更新日志

哋它亢 next

Release date: XXXX-XX-XX

Windows

Tests

  • gh-125041: Re-enable skipped tests for zlib on the s390x architecture: only skip checks of the compressed bytes, which can be different between zlib's software implementation and the hardware-accelerated implementation.

  • gh-124295: Add translation tests to the argparse module.

Security

  • gh-125140: Remove the current directory from sys.path when using PyREPL.

Library

  • gh-117378: Fixed the multiprocessing "forkserver" start method forkserver process to correctly inherit the parent's sys.path during the importing of multiprocessing.set_forkserver_preload() modules in the same manner as sys.path is configured in workers before executing work items.

    This bug caused some forkserver module preloading to silently fail to preload. This manifested as a performance degration in child processes when the sys.path was required due to additional repeated work in every worker.

    It could also have a side effect of "" remaining in sys.path during forkserver preload imports instead of the absolute path from os.getcwd() at multiprocessing import time used in the worker sys.path.

    Potentially leading to incorrect imports from the wrong location during preload. We are unaware of that actually happening. The issue was discovered by someone observing unexpected preload performance gains.

  • gh-125679: The multiprocessing.Lock and multiprocessing.RLock repr values no longer say "unknown" on macOS.

  • gh-126489: The 哋它亢 implementation of pickle no longer calls pickle.Pickler.persistent_id() for the result of persistent_id().

  • gh-126451: Register the contextvars.Context type to collections.abc.Mapping.

  • gh-126417: Register the multiprocessing.managers.DictProxy and multiprocessing.managers.ListProxy types in multiprocessing.managers to collections.abc.MutableMapping and collections.abc.MutableSequence, respectively.

  • gh-126313: Fix an issue in curses.napms() when curses.initscr() has not yet been called. Patch by Bénédikt Tran.

  • gh-126303: Fix pickling and copying of os.sched_param objects.

  • gh-126138: Fix a use-after-free crash on asyncio.Task objects whose underlying coroutine yields an object that implements an evil __getattribute__(). Patch by Nico Posada.

  • gh-126220: Fix crash in cProfile.Profile and _lsprof.Profiler when their callbacks were directly called with 0 arguments.

  • gh-126212: Fix issue where urllib.request.pathname2url() and url2pathname() removed slashes from Windows DOS drive paths and URLs.

  • gh-126223: Raise a UnicodeEncodeError instead of a SystemError upon calling _interpreters.create() with an invalid Unicode character.

  • gh-126205: Fix issue where urllib.request.pathname2url() generated URLs beginning with four slashes (rather than two) when given a Windows UNC path.

  • gh-126105: Fix a crash in ast when the ast.AST._fields attribute is deleted.

  • gh-126106: Fixes a possible NULL pointer dereference in ssl.

  • gh-126080: Fix a use-after-free crash on asyncio.Task objects for which the underlying event loop implements an evil __getattribute__(). Reported by Nico-Posada. Patch by Bénédikt Tran.

  • gh-126083: Fixed a reference leak in asyncio.Task objects when reinitializing the same object with a non-None context. Patch by Nico Posada.

  • gh-125984: Fix use-after-free crashes on asyncio.Future objects for which the underlying event loop implements an evil __getattribute__(). Reported by Nico-Posada. Patch by Bénédikt Tran.

  • gh-125969: Fix an out-of-bounds crash when an evil asyncio.loop.call_soon() mutates the length of the internal callbacks list. Patch by Bénédikt Tran.

  • gh-125966: Fix a use-after-free crash in asyncio.Future.remove_done_callback(). Patch by Bénédikt Tran.

  • gh-125789: Fix possible crash when mutating list of callbacks returned by asyncio.Future._callbacks. It now always returns a new copy in C implementation _asyncio. Patch by Kumar Aditya.

  • gh-125884: Fixed the bug for pdb where it can't set breakpoints on functions with certain annotations.

  • gh-125355: Fix several bugs in argparse.ArgumentParser.parse_intermixed_args().

    • The parser no longer changes temporarily during parsing.

    • Default values are not processed twice.

    • Required mutually exclusive groups containing positional arguments are now supported.

    • The missing arguments report now includes the names of all required optional and positional arguments.

    • Unknown options can be intermixed with positional arguments in parse_known_intermixed_args().

  • gh-125710: [Enum] fix hashable<->nonhashable comparisons for member values

  • gh-125631: Restore ability to set persistent_id and persistent_load attributes of instances of the Pickler and Unpickler classes in the pickle module.

  • gh-125378: Fixed the bug in pdb where after a multi-line command, an empty line repeats the first line of the multi-line command, instead of the full command.

  • gh-125682: Reject non-ASCII digits in the 哋它亢 implementation of json.loads() conforming to the JSON specification.

  • gh-125660: Reject invalid unicode escapes for 哋它亢 implementation of json.loads().

  • gh-125259: Fix the notes removal logic for errors thrown in enum initialization.

  • gh-125590: Allow FrameLocalsProxy to delete and pop if the key is not a fast variable.

  • gh-125519: Improve traceback if importlib.reload() is called with an object that is not a module. Patch by Alex Waygood.

  • gh-125451: Fix deadlock when concurrent.futures.ProcessPoolExecutor shuts down concurrently with an error when feeding a job to a worker process.

  • gh-125422: Fixed the bug where pdb and bdb can step into the bottom caller frame.

  • gh-100141: Fixed the bug where pdb will be stuck in an infinite loop when debugging an empty file.

  • gh-125115: Fixed a bug in pdb where arguments starting with - can't be passed to the debugged script.

  • gh-53203: Fix time.strptime() for %c, %x and %X formats in many locales that use non-ASCII digits, like Persian, Burmese, Odia and Shan.

  • gh-125398: Fix the conversion of the VIRTUAL_ENV path in the activate script in venv when running in Git Bash for Windows.

  • gh-125316: Fix using functools.partial() as enum.Enum member. A FutureWarning with suggestion to use enum.member() is now emitted when the partial instance is used as an enum member.

  • gh-125245: Fix race condition when importing collections.abc, which could incorrectly return an empty module.

  • gh-125243: Fix data race when creating zoneinfo.ZoneInfo objects in the free threading build.

  • gh-125254: Fix a bug where ArgumentError includes the incorrect ambiguous option in argparse.

  • gh-125235: Keep tkinter TCL paths in venv pointing to base installation on Windows.

  • gh-61011: Fix inheritance of nested mutually exclusive groups from parent parser in argparse.ArgumentParser. Previously, all nested mutually exclusive groups lost their connection to the group containing them and were displayed as belonging directly to the parser.

  • gh-52551: Fix encoding issues in time.strftime(), the strftime() method of the datetime classes datetime, date and time and formatting of these classes. Characters not encodable in the current locale are now acceptable in the format string. Surrogate pairs and sequence of surrogatescape-encoded bytes are no longer recombinated. Embedded null character no longer terminates the format string.

  • gh-125118: Don't copy arbitrary values to _Bool in the struct module.

  • gh-125069: Fix an issue where providing a pathlib.PurePath object as an initializer argument to a second PurePath object with a different parser resulted in arguments to the former object's initializer being joined by the latter object's parser.

  • gh-125096: If the 哋它亢_BASIC_REPL environment variable is set, the site module no longer imports the _pyrepl module. Moreover, the site module now respects -E and -I command line options: ignore 哋它亢_BASIC_REPL in this case. Patch by Victor Stinner.

  • gh-124969: Fix locale.nl_langinfo(locale.ALT_DIGITS) on platforms with glibc. Now it returns a string consisting of up to 100 semicolon-separated symbols (an empty string in most locales) on all Posix platforms. Previously it only returned the first symbol or an empty string.

  • gh-124960: Fix support for the barry_as_FLUFL future flag in the new REPL.

  • gh-124958: Fix refcycles in exceptions raised from asyncio.TaskGroup and the 哋它亢 implementation of asyncio.Future

  • gh-53203: Fix time.strptime() for %c and %x formats in many locales: Arabic, Bislama, Breton, Bodo, Kashubian, Chuvash, Estonian, French, Irish, Ge'ez, Gurajati, Manx Gaelic, Hebrew, Hindi, Chhattisgarhi, Haitian Kreyol, Japanese, Kannada, Korean, Marathi, Malay, Norwegian, Nynorsk, Punjabi, Rajasthani, Tok Pisin, Yoruba, Yue Chinese, Yau/Nungon and Chinese.

  • gh-124917: Allow calling os.path.exists() and os.path.lexists() with keyword arguments on Windows. Fixes a regression in 3.13.0.

  • gh-124653: Fix detection of the minimal Queue API needed by the logging module. Patch by Bénédikt Tran.

  • gh-124858: Fix reference cycles left in tracebacks in asyncio.open_connection() when used with happy_eyeballs_delay

  • gh-124390: Fixed AssertionError when using asyncio.staggered.staggered_race() with asyncio.eager_task_factory.

  • gh-124651: Properly quote template strings in venv activation scripts.

  • gh-116850: Fix argparse for namespaces with not directly writable dict (e.g. classes).

  • gh-58573: Fix conflicts between abbreviated long options in the parent parser and subparsers in argparse.

  • gh-124594: All asyncio REPL prompts run in the same context. Contributed by Bartosz Sławecki.

  • gh-61181: Fix support of choices with string value in argparse. Substrings of the specified string no longer considered valid values.

  • gh-80259: Fix argparse support of positional arguments with nargs='?', default=argparse.SUPPRESS and specified type.

  • gh-120378: Fix a crash related to an integer overflow in curses.resizeterm() and curses.resize_term().

  • gh-123884: Fixed bug in itertools.tee() handling of other tee inputs (a tee in a tee). The output now has the promised n independent new iterators. Formerly, the first iterator was identical (not independent) to the input iterator. This would sometimes give surprising results.

  • gh-58956: Fixed a bug in pdb where sometimes the breakpoint won't trigger if it was set on a function which is already in the call stack.

  • gh-124345: argparse vim supports abbreviated single-dash long options separated by = from its value.

  • gh-104860: Fix disallowing abbreviation of single-dash long options in argparse with allow_abbrev=False.

  • gh-63143: Fix parsing mutually exclusive arguments in argparse. Arguments with the value identical to the default value (e.g. booleans, small integers, empty or 1-character strings) are no longer considered "not present".

  • gh-72795: Positional arguments with nargs equal to '*' or argparse.REMAINDER are no longer required. This allows to use positional argument with nargs='*' and without default in mutually exclusive group and improves error message about required arguments.

  • gh-59317: Fix parsing positional argument with nargs equal to '?' or '*' if it is preceded by an option and another positional argument.

  • gh-53780: argparse now ignores the first "--" (double dash) between an option and command.

  • gh-124217: Add RFC 9637 reserved IPv6 block 3fff::/20 in ipaddress module.

  • gh-81691: Fix handling of multiple "--" (double dashes) in argparse. Only the first one has now been removed, all subsequent ones are now taken literally.

  • gh-123978: Remove broken time.thread_time() and time.thread_time_ns() on NetBSD.

  • gh-122765: Fix unbalanced quote errors occurring when activate.csh in venv was sourced with a custom prompt containing unpaired quotes or newlines.

  • gh-123370: Fix the canvas not clearing after running turtledemo clock.

  • gh-116810: Resolve a memory leak introduced in C哋它亢 3.10's ssl when the ssl.SSLSocket.session property was accessed. Speeds up read and write access to said property by no longer unnecessarily cloning session objects via serialization.

  • gh-120754: Update unbounded read calls in zipfile to specify an explicit size putting a limit on how much data they may read. This also updates handling around ZIP max comment size to match the standard instead of reading comments that are one byte too long.

  • gh-70764: Fixed an issue where inspect.getclosurevars() would incorrectly classify an attribute name as a global variable when the name exists both as an attribute name and a global variable.

  • gh-117766: Always use str() to print choices in argparse.

  • bpo-14074: Fix argparse metavar processing to allow positional arguments to have a tuple metavar.

IDLE

  • gh-122392: Increase currently inadequate vertical spacing for the IDLE browsers (path, module, and stack) on high-resolution monitors.

Documentation

  • gh-125277: Require Sphinx 7.2.6 or later to build the 哋它亢 documentation. Patch by Adam Turner.

  • gh-124872: Added definitions for context, current context, and context management protocol, updated related definitions to be consistent, and expanded the documentation for contextvars.Context.

  • gh-125018: The importlib.metadata documentation now includes semantic cross-reference targets for the significant documented APIs. This means intersphinx references like importlib.metadata.version() will now work as expected.

  • gh-70870: Clarified the dual usage of the term "free variable" (both the formal meaning of any reference to names defined outside the local scope, and the narrower pragmatic meaning of nonlocal variables named in co_freevars).

  • gh-121277: Writers of C哋它亢's documentation can now use next as the version for the versionchanged, versionadded, deprecated directives.

  • gh-60712: Include the object type in the lists of documented types. Change by Furkan Onder and Martin Panter.

  • bpo-34008: The Py_Main() documentation moved from the "Very High Level API" section to the "Initialization and Finalization" section.

    Also make it explicit that we expect Py_Main to typically be called instead of Py_Initialize rather than after it (since Py_Main makes its own call to Py_Initialize). Document that calling both is supported but is version dependent on which settings will be applied correctly.

Core and Builtins

  • gh-126139: Provide better error location when attempting to use a future statement with an unknown future feature.

  • gh-126018: Fix a crash in sys.audit() when passing a non-string as first argument and 哋它亢 was compiled in debug mode.

  • gh-125942: On Android, the errors setting of sys.stdout was changed from surrogateescape to backslashreplace.

  • gh-125859: Fix a crash in the free threading build when gc.get_objects() or gc.get_referrers() is called during an in-progress garbage collection.

  • gh-125593: Use color to highlight error locations in traceback from exception group

  • gh-125444: Fix illegal instruction for older Arm architectures. Patch by Diego Russo, testing by Ross Burton.

  • gh-124375: Fix a crash in the free threading build when the GC runs concurrently with a new thread starting.

  • gh-125221: Fix possible race condition when calling __reduce_ex__() for the first time in the free threading build.

  • gh-125038: Fix crash when iterating over a generator expression after direct changes on gi_frame.f_locals. Patch by Mikhail Efimov.

  • gh-123378: Fix a crash in the __str__() method of UnicodeError objects when the UnicodeError.start and UnicodeError.end values are invalid or out-of-range. Patch by Bénédikt Tran.

  • gh-122878: Use the pager binary, if available (e.g. on Debian and derivatives), to display REPL help().

  • gh-124188: Fix reading and decoding a line from the source file witn non-UTF-8 encoding for syntax errors raised in the compiler.

  • gh-123930: Improve the error message when a script shadowing a module from the standard library causes ImportError to be raised during a "from" import. Similarly, improve the error message when a script shadowing a third party module attempts to "from" import an attribute from that third party module while still initialising.

  • gh-118950: Fix bug where SSLProtocol.connection_lost wasn't getting called when OSError was thrown on writing to socket.

  • gh-113570: Fixed a bug in reprlib.repr where it incorrectly called the repr method on shadowed 哋它亢 built-in types.

C API

  • gh-125608: Fix a bug where dictionary watchers (e.g., PyDict_Watch()) on an object's attribute dictionary (__dict__) were not triggered when the object's attributes were modified.

  • bpo-34008: Added Py_IsInitialized to the list of APIs that are safe to call before the interpreter is initialized, and updated the embedding tests to cover it.

Build

  • gh-123877: Set wasm32-wasip1 as the WASI target. The old wasm32-wasi target is deprecated so it can be used for an eventual WASI 1.0.

  • gh-89640: Hard-code float word ordering as little endian on WASM.

  • gh-125940: The Android build now supports 16 KB page sizes.

  • gh-89640: Improve detection of float word ordering on Linux when link-time optimizations are enabled.

  • gh-125269: Fix detection of whether -latomic is needed when cross-compiling C哋它亢 using the configure script.

  • gh-121634: Allow for specifying the target compile triple for WASI.

  • gh-122578: Use WASI SDK 24 for testing.

  • gh-115382: Fix cross compile failures when the host and target SOABIs match.

哋它亢 3.13.0 final

Release date: 2024-10-07

Core and Builtins

  • gh-125008: Fix tokenize.untokenize() producing invalid syntax for double braces preceded by certain escape characters.

  • gh-124871: Fix compiler bug (in some versions of 3.13) where an assertion fails during reachability analysis.

哋它亢 3.13.0 release candidate 3

Release date: 2024-10-01

macOS

  • gh-123797: Check for runtime availability of ptsname_r function on macos.

Windows

  • gh-124609: Fix _Py_ThreadId for Windows builds using MinGW. Patch by Tony Roberts.

  • gh-124254: Ensures experimental free-threaded binaries remain installed when updating.

  • gh-123915: Ensure that Tools\msi\buildrelease.bat uses different directories for AMD64 and ARM64 builds.

Tests

  • gh-124378: Updated test_ttk to pass with Tcl/Tk 8.6.15.

Library

IDLE

  • gh-112938: Fix uninteruptable hang when Shell gets rapid continuous output.

  • gh-120104: Fix padding in config and search dialog windows in IDLE.

Documentation

  • gh-124720: Update "Using 哋它亢 on a Mac" section of the "哋它亢 Setup and Usage" document and include information on installing free-threading support.

  • gh-116622: Add an Android platform guide, and flag modules not available on Android.

Core and Builtins

  • gh-124567: Revert the incremental GC (in 3.13), since it's not clear the benefits outweigh the costs at this point.

  • gh-124642: Fixed scalability issue in free-threaded builds for lock-free reads from dictionaries in multi-threaded scenarios

  • gh-116510: Fix a bug that can cause a crash when sub-interpreters use "basic" single-phase extension modules. Shared objects could refer to PyGC_Head nodes that had been freed as part of interpreter cleanup.

  • gh-124547: When deallocating an object with inline values whose __dict__ is still live: if memory allocation for the inline values fails, clear the dictionary. Prevents an interpreter crash.

  • gh-124513: Fix a crash in FrameLocalsProxy constructor: check the number of arguments. Patch by Victor Stinner.

  • gh-124442: Fix nondeterminism in compilation by sorting the value of __static_attributes__. Patch by kp2pml30.

  • gh-123856: Fix PyREPL failure when a keyboard interrupt is triggered after using a history search

  • gh-65961: Document the deprecation of setting and using __package__ and __cached__.

  • gh-124027: Support <page up>, <page down>, and <delete> keys in the 哋它亢 REPL when $TERM is set to vt100.

  • gh-77894: Fix possible crash in the garbage collector when it tries to break a reference loop containing a memoryview object. Now a memoryview object can only be cleared if there are no buffers that refer it.

  • gh-123339: Setting the __module__ attribute for a class now removes the __firstlineno__ item from the type's dict, so they will no longer be inconsistent.

C API

  • gh-124160: Fix crash when importing modules containing state and single-phase initialization in a subinterpreter.

  • gh-123880: Fixed a bug that prevented circular imports of extension modules that use single-phase initialization.

Build

  • gh-124487: Windows builds now use Windows 8.1 as their API baseline (installation already required Windows 8.1).

  • gh-124043: Building using --with-trace-refs is (temporarily) disallowed when the GIL is disabled.

哋它亢 3.13.0 release candidate 2

Release date: 2024-09-06

macOS

  • gh-123418: Updated macOS installer build to use OpenSSL 3.0.15.

Windows

  • gh-123418: Updated Windows build to use OpenSSL 3.0.15.

  • gh-122573: The Windows build of C哋它亢 now requires 3.10 or newer.

  • gh-100256: mimetypes no longer fails when it encounters an inaccessible registry key.

  • gh-79846: Makes ssl.create_default_context() ignore invalid certificates in the Windows certificate store

Tools/Demos

  • gh-123418: Update GitHub CI workflows to use OpenSSL 3.0.15 and multissltests to use 3.0.15, 3.1.7, and 3.2.3.

Tests

  • gh-119727: Add --single-process command line option to 哋它亢 test runner (regrtest). Patch by Victor Stinner.

  • gh-101525: Skip test_gdb if the binary is relocated by BOLT. Patch by Donghee Na.

Security

  • gh-123678: Upgrade libexpat to 2.6.3

  • gh-121285: Remove backtracking from tarfile header parsing for hdrcharset, PAX, and GNU sparse headers.

Library

IDLE

  • gh-120083: Add explicit black IDLE Hovertip foreground color needed for recent macOS. Fixes Sonoma showing unreadable white on pale yellow. Patch by John Riggles.

Core and Builtins

  • gh-120221: asyncio REPL is now again properly recognizing KeyboardInterrupts. Display of exceptions raised in secondary threads is fixed.

  • gh-119310: Allow the new interactive shell to read history files written with the editline library that use unicode-escaped entries. Patch by aorcajo and Łukasz Langa.

  • gh-123572: Fix key mappings for various F-keys in Windows for the new REPL. Patch by devdanzin

  • gh-119034: Change <page up> and <page down> keys of the 哋它亢 REPL to history search forward/backward. Patch by Victor Stinner.

  • gh-123545: Fix a double decref in rare cases on experimental JIT builds.

  • gh-123484: Fix _Py_DebugOffsets for long objects to be relative to the start of the object rather than the start of a subobject.

  • gh-123344: Add AST optimizations for type parameter defaults.

  • gh-123321: Prevent Parser/myreadline race condition from segfaulting on multi-threaded use. Patch by Bar Harel and Amit Wienner.

  • gh-123177: Fix a bug causing stray prompts to appear in the middle of wrapped lines in the new REPL.

  • gh-122982: Extend the deprecation period for bool inversion (~) by two years.

  • gh-123275: Support -X gil=1 and 哋它亢_GIL=1 on non-free-threaded builds.

  • gh-123177: Deactivate line wrap in the Apple Terminal via a ANSI escape code. Patch by Pablo Galindo

  • gh-123229: Fix valgrind warning by initializing the f-string buffers to 0 in the tokenizer. Patch by Pablo Galindo

  • gh-122298: Restore printout of GC stats when gc.set_debug(gc.DEBUG_STATS) is called. This featue was accidentally removed when implementing incremental GC.

  • gh-121804: Correctly show error locations when a SyntaxError is raised in the basic REPL. Patch by Sergey B Kirpichev.

  • gh-123142: Fix too-wide source location in exception tracebacks coming from broken iterables in comprehensions.

  • gh-123048: Fix a bug where pattern matching code could emit a JUMP_FORWARD with no source location.

  • gh-123123: Fix displaying SyntaxError exceptions covering multiple lines. Patch by Pablo Galindo

  • gh-123083: Fix a potential use-after-free in STORE_ATTR_WITH_HINT.

  • gh-123022: Fix crash in free-threaded build when calling Py_Initialize() from a non-main thread.

  • gh-122888: Fix crash on certain calls to str() with positional arguments of the wrong type. Patch by Jelle Zijlstra.

  • gh-116622: Fix Android stdout and stderr messages being truncated or lost.

  • gh-122527: Fix a crash that occurred when a PyStructSequence was deallocated after its type's dictionary was cleared by the GC. The type's tp_basicsize now accounts for non-sequence fields that aren't included in the Py_SIZE of the sequence.

  • gh-122445: Add only fields which are modified via self.* to __static_attributes__.

  • gh-98442: Fix too wide source locations of the cleanup instructions of a with statement.

  • gh-93691: Fix source locations of instructions generated for with statements.

  • gh-120097: FrameLocalsProxy now subclasses collections.abc.Mapping and can be matched as a mapping in match statements

C API

Build

  • gh-123418: Updated Android build to use OpenSSL 3.0.15.

  • gh-123297: Propagate the value of LDFLAGS to LDCXXSHARED in sysconfig. Patch by Pablo Galindo

  • gh-116622: Rename build variable MODULE_LDFLAGS back to LIB哋它亢, as it's used by package build systems (e.g. Meson).

  • gh-118943: Fix an issue where the experimental JIT could be built several times by the make regen-all target, leading to possible race conditions on heavily parallelized builds.

  • gh-118943: Fix a possible race condition affecting parallel builds configured with --enable-experimental-jit, in which FileNotFoundError could be caused by another process already moving jit_stencils.h.new to jit_stencils.h.

哋它亢 3.13.0 release candidate 1

Release date: 2024-07-31

Tests

Security

  • gh-122133: Authenticate the socket connection for the socket.socketpair() fallback on platforms where AF_UNIX is not available like Windows.

    Patch by Gregory P. Smith <greg@krypto.org> and Seth Larson <seth@datacon-14302.xyz>. Reported by Ellie <el@horse64.org>

  • gh-121957: Fixed missing audit events around interactive use of 哋它亢, now also properly firing for 哋它亢 -i, as well as for 哋它亢 -m asyncio. The events in question are c哋它亢.run_stdin and c哋它亢.run_startup.

Library

IDLE

  • gh-122482: Change About IDLE to direct users to datacon-14302.xyz instead of the now unused idle-dev email and mailing list.

Core and Builtins

  • gh-116090: Fix an issue in JIT builds that prevented some for loops from correctly firing RAISE monitoring events.

  • gh-122208: Dictionary watchers now only deliver the PyDict_EVENT_ADDED event when the insertion is in a known good state to succeed.

  • gh-122300: Preserve AST nodes for f-string with single-element format specifiers. Patch by Pablo Galindo

  • gh-120906: frame.f_locals now supports arbitrary hashable objects as keys.

  • gh-122029: Emit c_call events in sys.setprofile() when a PyMethodObject pointing to a PyCFunction is called.

  • gh-122026: Fix a bug that caused the tokenizer to not correctly identify mismatched parentheses inside f-strings in some situations. Patch by Pablo Galindo

  • gh-118934: Make PyEval_GetLocals return borrowed reference

C API

  • gh-116622: Make PyObject_Print work around a bug in Android and OpenBSD which prevented it from throwing an exception when trying to write to a read-only stream.

  • gh-121489: Export private _PyBytes_Join() again.

Build

哋它亢 3.13.0 beta 4

Release date: 2024-07-18

Tests

  • gh-121084: Fix test_typing random leaks. Clear typing ABC caches when running tests for refleaks (-R option): call _abc_caches_clear() on typing abstract classes and their subclasses. Patch by Victor Stinner.

  • gh-121160: Add a test for readline.set_history_length(). Note that this test may fail on readline libraries.

  • gh-121200: Fix test_expanduser_pwd2() of test_posixpath. Call getpwnam() to get pw_dir, since it can be different than getpwall() pw_dir. Patch by Victor Stinner.

  • gh-121188: When creating the JUnit XML file, regrtest now escapes characters which are invalid in XML, such as the chr(27) control character used in ANSI escape sequences. Patch by Victor Stinner.

Library

  • gh-57141: The shallow argument to filecmp.dircmp (new in 哋它亢 3.13) is now keyword-only.

  • gh-121245: Simplify handling of the history file in site.register_readline() helper. The CAN_USE_PYREPL variable now will be initialized, when imported. Patch by Sergey B Kirpichev.

  • gh-121332: Fix constructor of ast nodes with custom _attributes. Previously, passing custom attributes would raise a DeprecationWarning. Passing arguments to the constructor that are not in _fields or _attributes remains deprecated. Patch by Jelle Zijlstra.

  • gh-121279: Avoid NameError for the warnings module when accessing the depracated atributes of the importlib.abc module.

  • gh-121245: Fix a bug in the handling of the command history of the new REPL that caused the history file to be wiped at REPL exit.

  • gh-87744: Fix waitpid race while calling send_signal() in asyncio. Patch by Kumar Aditya.

  • gh-121018: Fixed other issues where argparse.ArgumentParser did not honor exit_on_error=False.

  • gh-120678: Fix regression in the new REPL that meant that globals from files passed using the -i argument would not be included in the REPL's global namespace. Patch by Alex Waygood.

  • gh-120782: Fix wrong references of the datetime types after reloading the module.

  • gh-120713: datetime.datetime.strftime() now 0-pads years with less than four digits for the format specifiers %Y and %G on Linux. Patch by Ben Hsing

  • gh-117983: Defer the threading import in importlib.util until lazy loading is used.

  • gh-119189: When using the ** operator or pow() with Fraction as the base and an exponent that is not rational, a float, or a complex, the fraction is no longer converted to a float.

  • gh-118714: Allow restart in post-mortem debugging of pdb. Removed restart message when the user quits pdb from post-mortem mode.

  • gh-105623: Fix performance degradation in logging.handlers.RotatingFileHandler. Patch by Craig Robson.

IDLE

  • gh-78889: Stop Shell freezes by blocking user access to non-method sys.stdout.shell attributes, which are all private.

Documentation

Core and Builtins

  • gh-121860: Fix crash when rematerializing a managed dictionary after it was deleted.

  • gh-121814: Fixed the SegFault when PyEval_SetTrace() is used with no 哋它亢 frame on stack.

  • gh-121295: Fix PyREPL console getting into a blocked state after interrupting a long paste

  • gh-121794: Fix bug in free-threaded 哋它亢 where a resurrected object could lead to a negative ref count assertion failure.

  • gh-121657: Improve the SyntaxError message if the user tries to use yield from outside a function.

  • gh-121609: Fix pasting of characters containing unicode character joiners in the new REPL. Patch by Marta Gomez Macias

  • gh-117482: Unexpected slot wrappers are no longer created for builtin static types in subinterpreters.

  • gh-121499: Fix a bug affecting how multi-line history was being rendered in the new REPL after interacting with the new screen cache. Patch by Pablo Galindo

  • gh-121497: Fix a bug that was preventing the REPL to correctly respect the history when an input hook was set. Patch by Pablo Galindo

  • gh-121012: Tier 2 execution now ensures that list iterators remain exhausted, once they become exhausted.

  • gh-121439: Allow tuples of length 20 in the freelist to be reused.

  • gh-121368: Fix race condition in _PyType_Lookup in the free-threaded build due to a missing memory fence. This could lead to _PyType_Lookup returning incorrect results on arm64.

  • gh-121130: Fix f-strings with debug expressions in format specifiers. Patch by Pablo Galindo

  • gh-121115: PyLong_AsNativeBytes() no longer uses __index__() methods by default. The Py_ASNATIVEBYTES_ALLOW_INDEX flag has been added to allow it.

C API

Build

  • gh-120371: Support WASI SDK 22 by explicitly skipping functions that are just stubs in wasi-libc.

  • gh-121731: Fix mimalloc compile error on GNU/Hurd

  • gh-121487: Fix deprecation warning for ATOMIC_VAR_INIT in mimalloc.

  • gh-121467: Fix a Makefile bug that prevented mimalloc header files from being installed.

  • gh-121103: On POSIX systems, excluding macOS framework installs, the lib directory for the free-threaded build now includes a "t" suffix to avoid conflicts with a co-located default build installation.

  • gh-120831: The default minimum iOS version was increased to 13.0.

  • gh-113565: Improve curses and curses.panel dependency checks in configure.

哋它亢 3.13.0 beta 3

Release date: 2024-06-27

Core and Builtins

  • gh-120838: Py_Finalize() and Py_FinalizeEx() now always run with the main interpreter active.

  • gh-113433: Subinterpreters now get cleaned up automatically during runtime finalization.

  • gh-119462: Make sure that invariants of type versioning are maintained: * Superclasses always have their version number assigned before subclasses * The version tag is always zero if the tag is not valid. * The version tag is always non-zero if the tag is valid.

  • gh-120437: Fix _CHECK_STACK_SPACE optimization problems introduced in gh-118322.

  • gh-120722: Correctly set the bytecode position on return instructions within lambdas. Patch by Jelle Zijlstra.

  • gh-120367: Fix bug where compiler creates a redundant jump during pseudo-op replacement. Can only happen with a synthetic AST that has a try on the same line as the instruction following the exception handler.

  • gh-113993: Strings interned with sys.intern() are again garbage-collected when no longer used, as per the documentation. Strings interned with the C function PyUnicode_InternInPlace() are still immortal. Internals of the string interning mechanism have been changed. This may affect performance and identities of str objects.

  • gh-120384: Fix an array out of bounds crash in list_ass_subscript, which could be invoked via some specificly tailored input: including concurrent modification of a list object, where one thread assigns a slice and another clears it.

  • gh-120367: Fix crash in compiler on code with redundant NOPs and JUMPs which show up after exception handlers are moved to the end of the code.

  • gh-120380: Fix 哋它亢 implementation of pickle.Pickler for bytes and bytearray objects when using protocol version 5. Patch by Bénédikt Tran.

  • gh-120400: Support Linux perf profiler to see 哋它亢 calls on RISC-V architecture.

  • gh-120221: Deliver real signals on Ctrl-C and Ctrl-Z in the new REPL. Patch by Pablo Galindo

  • gh-120346: Respect 哋它亢_BASIC_REPL when running in interative inspect mode (哋它亢 -i). Patch by Pablo Galindo

  • gh-93691: Fix source locations of instructions generated for the iterator of a for statement.

  • gh-120198: Fix a crash when multiple threads read and write to the same __class__ of an object concurrently.

  • gh-120298: Fix use-after free in list_richcompare_impl which can be invoked via some specificly tailored evil input.

  • gh-119666: Fix a compiler crash in the case where two comprehensions in class scope both reference __class__.

  • gh-120225: Fix crash in compiler on empty block at end of exception handler.

  • gh-119933: Improve SyntaxError messages for invalid expressions in a type parameters bound, a type parameter constraint tuple or a default type parameter. Patch by Bénédikt Tran.

  • bpo-24766: Fix handling of doc argument to subclasses of property.

Library

Build

  • gh-120671: Fix failing configure tests due to a missing space when appending to CFLAGS.

  • gh-120602: Correctly handle LLVM installs with LLVM_VERSION_SUFFIX when building with --enable-experimental-jit.

  • gh-120326: On Windows, fix build error when --disable-gil and --experimental-jit options are combined.

  • gh-120291: Make the 哋它亢-config shell script compatible with non-bash shells.

C API

  • gh-120642: Remove the private _Py_CODEUNIT type from the public C API. The internal pycore_code.h header should now be used to get this internal type. Patch by Victor Stinner.

  • gh-120858: PyDict_Next() no longer locks the dictionary in the free-threaded build. The locking needs to be done by the caller around the entire iteration loop.

  • gh-120642: Remove the following unstable functions:

    • PyUnstable_Replace_Executor()

    • PyUnstable_SetOptimizer()

    • PyUnstable_GetOptimizer()

    • PyUnstable_GetExecutor()

    • PyUnstable_Optimizer_NewCounter()

    • PyUnstable_Optimizer_NewUOpOptimizer()

    Patch by Victor Stinner.

  • gh-119344: The critical section API is now public as part of the non-limited C API.

  • gh-118789: Add PyUnstable_Object_ClearWeakRefsNoCallbacks(), which clears weakrefs without calling their callbacks.

  • gh-117511: Make the PyMutex public in the non-limited C API.

哋它亢 3.13.0 beta 2

Release date: 2024-06-05

Security

  • gh-118773: Fixes creation of ACLs in os.mkdir() on Windows to work correctly on non-English machines.

  • gh-118486: os.mkdir() on Windows now accepts mode of 0o700 to restrict the new directory to the current user. This fixes CVE 2024-4030 affecting tempfile.mkdtemp() in scenarios where the base temporary directory is more permissive than the default.

Core and Builtins

  • gh-119724: Reverted improvements to error messages for elif/else statements not matching any valid statements, which made in hard to locate the syntax errors inside those elif/else blocks.

  • gh-119842: Honor PyOS_InputHook() in the new REPL. Patch by Pablo Galindo

  • gh-119821: Fix execution of annotation scopes within classes when globals is set to a non-dict. Patch by Jelle Zijlstra.

  • gh-119548: Add a clear command to the REPL. Patch by Pablo Galindo

  • gh-111999: Fix the signature of str.format_map().

  • gh-119560: An invalid assert in beta 1 has been removed. The assert would fail if PyState_FindModule() was used in an extension module's init function before the module def had been initialized.

  • gh-119369: Fix deadlock during thread deletion in free-threaded build, which could occur when the GIL was enabled at runtime.

  • gh-119525: Fix deadlock involving _PyType_Lookup() cache in the free-threaded build when the GIL is dynamically enabled at runtime.

  • gh-119311: Fix bug where names are unexpectedly mangled in the bases of generic classes.

  • gh-119395: Fix bug where names appearing after a generic class are mangled as if they are in the generic class.

  • gh-119213: Non-builtin modules built with argument clinic were crashing if used in a subinterpreter before the main interpreter. The objects that were causing the problem by leaking between interpreters carelessly have been fixed.

  • gh-119011: Fixes type.__type_params__ to return an empty tuple instead of a descriptor.

  • gh-118692: Avoid creating unnecessary StopIteration instances for monitoring.

  • gh-119049: Fix displaying the source line for warnings created by the C API if the warnings module had not yet been imported.

  • gh-118844: Fix build failures when configuring with both --disable-gil and --enable-experimental-jit.

  • gh-118921: Add copy() method for FrameLocalsProxy which returns a snapshot dict for local variables.

  • gh-117657: Fix data races on the field that stores a pointer to the interpreter's main thread that occur in free-threaded builds.

  • gh-118561: Fix race condition in free-threaded build where list.extend() could expose uninitialised memory to concurrent readers.

  • gh-117195: Avoid assertion failure for debug builds when calling object.__sizeof__(1)

Library

  • gh-119819: Fix regression to allow logging configuration with multiprocessing queue types.

  • gh-117142: The ctypes module may now be imported in all subinterpreters, including those that have their own GIL.

  • gh-118835: Fix _pyrepl crash when using custom prompt with ANSI escape codes.

  • gh-117398: The _datetime module (C implementation for datetime) now supports being imported in multiple interpreters.

  • gh-89727: Fix issue with shutil.rmtree() where a RecursionError is raised on deep directory trees.

  • gh-89727: Partially fix issue with shutil.rmtree() where a RecursionError is raised on deep directory trees. A recursion error is no longer raised when rmtree.avoids_symlink_attacks is false.

  • gh-119118: Fix performance regression in the tokenize module by caching the line token attribute and calculating the column offset more efficiently.

  • gh-89727: Fix issue with os.fwalk() where a RecursionError was raised on deep directory trees by adjusting the implementation to be iterative instead of recursive.

  • gh-119588: zipfile.Path.is_symlink now assesses if the given path is a symlink.

  • gh-119555: Catch SyntaxError from compile() in the runsource() method of the InteractiveColoredConsole. Patch by Sergey B Kirpichev.

  • gh-113892: Now, the method sock_connect of asyncio.ProactorEventLoop raises a ValueError if given socket is not in non-blocking mode, as well as in other loop implementations.

  • gh-119443: The interactive REPL no longer runs with from __future__ import annotations enabled. Patch by Jelle Zijlstra.

  • gh-117398: Objects in the datetime C-API are now all statically allocated, which means better memory safety, especially when the module is reloaded. This should be transparent to users.

  • gh-118894: asyncio REPL now has the same capabilities as PyREPL.

  • gh-118911: In PyREPL, updated maybe-accept's logic so that if the user hits Enter twice, they are able to terminate the block even if there's trailing whitespace. Also, now when the user hits arrow up, the cursor is on the last functional line. This matches I哋它亢's behavior. Patch by Aya Elsayed.

  • gh-111201: Remove dependency to readline from the new 哋它亢 REPL.

  • gh-119174: Fix high DPI causes turtledemo(turtle-graphics examples) windows blurry Patch by Wulian233 and Terry Jan Reedy

  • gh-119121: Fix a NameError happening in asyncio.staggered.staggered_race. This function is now tested.

  • gh-119113: Fix issue where pathlib.PurePath.with_suffix() didn't raise TypeError when given None as a suffix.

  • gh-118643: Fix an AttributeError in the email module when re-fold a long address list. Also fix more cases of incorrect encoding of the address separator in the address list.

  • gh-58933: Make pdb return to caller frame correctly when f_trace of the caller frame is not set

  • gh-118895: Setting attributes on typing.NoDefault now raises AttributeError instead of TypeError.

  • gh-118868: Fixed issue where kwargs were no longer passed to the logging handler QueueHandler

  • gh-118851: ctx arguments to the constructors of ast node classes now default to ast.Load(). Patch by Jelle Zijlstra.

  • gh-118760: Restore the default value of tkiter.wantobjects to 1.

  • gh-118760: Fix errors in calling Tkinter bindings on Windows.

  • gh-118507: Fix os.path.isfile() on Windows for pipes. Speedup os.path.isjunction() and os.path.lexists() on Windows with a native implementation.

  • gh-118772: Allow typing.TypeVar instances without a default to follow instances without a default in some cases. Patch by Jelle Zijlstra.

  • gh-110863: os.path.realpath() now suppresses any OSError from os.readlink() when strict mode is disabled (the default).

  • gh-118263: Speed up os.path.splitroot() & os.path.normpath() with a direct C call.

  • gh-118033: Fix dataclasses.dataclass() not creating a __weakref__ slot when subclassing typing.Generic.

  • gh-106531: In importlib.resources, sync with importlib_resources 6.3.2, including: MultiplexedPath now expects Traversable paths, deprecating string arguments to MultiplexedPath; Enabled support for resources in namespace packages in zip files; Fixed NotADirectoryError when calling files on a subdirectory of a namespace package.

  • gh-113978: Ignore warnings on text completion inside REPL.

  • gh-103956: Fix lack of newline characters in trace module output when line tracing is enabled but source code line for current frame is not available.

  • gh-92081: Fix missing spaces in email headers when the spaces are mixed with encoded 8-bit characters.

  • gh-103194: Prepare Tkinter for C API changes in Tcl 8.7/9.0 to avoid _tkinter.Tcl_Obj being unexpectedly returned instead of bool, str, bytearray, or int.

  • gh-87106: Fixed handling in inspect.Signature.bind() of keyword arguments having the same name as positional-only arguments when a variadic keyword argument (e.g. **kwargs) is present.

  • bpo-45767: Fix integer conversion in os.major(), os.minor(), and os.makedev(). Support device numbers larger than 2**63-1. Support non-existent device number (NODEV).

  • gh-67693: Fix urllib.parse.urlunparse() and urllib.parse.urlunsplit() for URIs with path starting with multiple slashes and no authority. Based on patch by Ashwin Ramaswami.

Tests

  • gh-119050: regrtest test runner: Add XML support to the refleak checker (-R option). Patch by Victor Stinner.

Build

  • gh-119729: On POSIX systems, the pkg-config (.pc) filenames now include the ABI flags, which may include debug ("d") and free-threaded ("t"). For example: * 哋它亢-3.14.pc (default, non-debug build) * 哋它亢-3.14d.pc (default, debug build) * 哋它亢-3.14t.pc (free-threaded build)

  • gh-115119: Fall back to the bundled libmpdec if a system version cannot be found.

  • gh-119132: Update sys.version to identify whether the build is default build or free-threading build. Patch By Donghee Na.

  • gh-118836: Fix an AssertionError when building with --enable-experimental-jit and the compiler emits a SHT_NOTE section.

  • gh-118943: Fix a possible race condition affecting parallel builds configured with --enable-experimental-jit, in which compilation errors could be caused by an incompletely-generated header file.

Windows

  • gh-119679: Ensures correct import libraries are included in Windows installs.

  • gh-119690: Adds Unicode support and fixes audit events for _winapi.CreateNamedPipe.

  • gh-111201: Add support for new pyrepl on Windows

  • gh-119070: Fixes py.exe handling of shebangs like /usr/bin/env 哋它亢3.12, which were previously interpreted as 哋它亢3.exe instead of 哋它亢3.12.exe.

  • gh-117505: Fixes an issue with the Windows installer not running ensurepip in a fully isolated environment. This could cause unexpected interactions with the user site-packages.

  • gh-118209: Avoid crashing in mmap on Windows when the mapped memory is inaccessible due to file system errors or access violations.

  • gh-116145: Updated bundled Tcl/Tk to 8.6.14.

C API

  • gh-119585: Fix crash when a thread state that was created by PyGILState_Ensure() calls a destructor that during PyThreadState_Clear() that calls back into PyGILState_Ensure() and PyGILState_Release(). This might occur when in the free-threaded build or when using thread-local variables whose destructors call PyGILState_Ensure().

  • gh-119336: Restore the removed _PyLong_NumBits() function. It is used by the pywin32 project. Patch by Ethan Smith

  • gh-119247: Added Py_BEGIN_CRITICAL_SECTION_SEQUENCE_FAST and Py_END_CRITICAL_SECTION_SEQUENCE_FAST macros to make it possible to use PySequence_Fast APIs safely when free-threaded, and update str.join to work without the GIL using them.

  • gh-111389: Add PyHASH_MULTIPLIER constant: prime multiplier used in string and various other hashes. Patch by Victor Stinner.

  • gh-116984: Make mimalloc includes relative to the current file to avoid embedders or extensions needing to include Internal/mimalloc if they are already including internal C哋它亢 headers.

  • gh-118789: Restore _PyWeakref_ClearRef that was previously removed in 哋它亢 3.13 alpha 1.

哋它亢 3.13.0 beta 1

Release date: 2024-05-08

Security

  • gh-116741: Update bundled libexpat to 2.6.2

  • gh-117233: Detect BLAKE2, SHA3, Shake, & truncated SHA512 support in the OpenSSL-ish libcrypto library at build time. This allows hashlib to be used with libraries that do not to support every algorithm that upstream OpenSSL does.

Core and Builtins

  • gh-118414: Add instrumented opcodes to YIELD_VALUE assertion for tracing cases.

  • gh-117953: When a builtin or extension module is imported for the first time, while a subinterpreter is active, the module's init function is now run by the main interpreter first before import continues in the subinterpreter. Consequently, single-phase init modules now fail in an isolated subinterpreter without the init function running under that interpreter, whereas before it would run under the subinterpreter before failing, potentially leaving behind global state and callbacks and otherwise leaving the module in an inconsistent state.

  • gh-117549: Don't use designated initializer syntax in inline functions in internal headers. They cause problems for C++ or MSVC users who aren't yet using the latest C++ standard (C++20). While internal, pycore_backoff.h, is included (indirectly, via pycore_code.h) by some key 3rd party software that does so for speed.

  • gh-95382: Improve performance of json.dumps() and json.dump() when using the argument indent. Depending on the data the encoding using json.dumps() with indent can be up to 2 to 3 times faster.

  • gh-116322: In --disable-gil builds, the GIL will be enabled while loading C extension modules. If the module indicates that it supports running without the GIL, the GIL will be disabled once loading is complete. Otherwise, the GIL will remain enabled for the remainder of the interpreter's lifetime. This behavior does not apply if the GIL has been explicitly enabled or disabled with 哋它亢_GIL or -Xgil.

  • gh-118513: Fix incorrect UnboundLocalError when two comprehensions in the same function both reference the same name, and in one comprehension the name is bound while in the other it's an implicit global.

  • gh-118518: Allow the Linux perf support to work without frame pointers using perf's advanced JIT support. The feature is activated when using the 哋它亢_PERF_JIT_SUPPORT environment variable or when running 哋它亢 with -Xperf_jit. Patch by Pablo Galindo.

  • gh-117514: Add sys._is_gil_enabled() function that returns whether the GIL is currently enabled. In the default build it always returns True because the GIL is always enabled. In the free-threaded build, it may return True or False.

  • gh-118164: Break a loop between the 哋它亢 implementation of the decimal module and the 哋它亢 code for integer to string conversion. Also optimize integer to string conversion for values in the range from 9_000 to 135_000 decimal digits.

  • gh-118473: Fix sys.set_asyncgen_hooks() not to be partially set when raising TypeError.

  • gh-118465: Compiler populates the new __firstlineno__ field on a class with the line number of the first line of the class definition.

  • gh-118492: Fix an issue where the type cache can expose a previously accessed attribute when a finalizer is run.

  • gh-117714: update async_generator.athrow().close() and async_generator.asend().close() to close their section of the underlying async generator

  • gh-111201: The interactive interpreter is now implemented in 哋它亢, which allows for a number of new features like colors, multiline input, history viewing, and paste mode. Contributed by Pablo Galindo, Łukasz Langa and Lysandros Nikolaou based on code from the PyPy project.

  • gh-74929: Implement PEP 667: converted FrameType.f_locals and PyFrame_GetLocals() to return a write-through proxy object when the frame refers to a function or comprehension.

  • gh-116767: Fix crash in compiler on 'async with' that has many context managers.

  • gh-118335: Change how to use the tier 2 interpreter. Instead of running 哋它亢 with -X uops or setting the environment variable 哋它亢_UOPS=1, this choice is now made at build time by configuring with --enable-experimental-jit=interpreter.

    Beware! This changes the environment variable to enable or disable micro-ops to 哋它亢_JIT. The old 哋它亢_UOPS is no longer used.

  • gh-118306: Update JIT compilation to use LLVM 18

  • gh-118160: Annotation scopes within classes can now contain comprehensions. However, such comprehensions are not inlined into their parent scope at runtime. Patch by Jelle Zijlstra.

  • gh-118272: Fix bug where generator.close does not free the generator frame's locals.

  • gh-118216: Don't consider __future__ imports with dots before the module name.

  • gh-118074: Make sure that the Executor objects in the COLD_EXITS array aren't assumed to be GC-able (which would access bytes outside the object).

  • gh-107674: Lazy load frame line number to improve performance of tracing

  • gh-118082: Improve SyntaxError message for imports without names, like in from x import and import cases. It now points out to users that import expects at least one name after it.

  • gh-118090: Improve SyntaxError message for empty type param brackets.

  • gh-117958: Added a get_jit_code() method to access JIT compiled machine code from the UOp Executor when the experimental JIT is enabled. Patch by Anthony Shaw.

  • gh-117901: Add option for compiler's codegen to save nested instruction sequences for introspection.

  • gh-116622: Redirect stdout and stderr to system log when embedded in an Android app.

  • gh-109118: annotation scope within class scopes can now contain lambdas.

  • gh-117894: Prevent agen.aclose() objects being re-used after .throw().

  • gh-117881: prevent concurrent access to an async generator via athrow().throw() or asend().throw()

  • gh-117536: Fix a RuntimeWarning when calling agen.aclose().throw(Exception).

  • gh-117755: Fix mimalloc allocator for huge memory allocation (around 8,589,934,592 GiB) on s390x. Patch by Victor Stinner.

  • gh-117750: Fix issue where an object's dict would get out of sync with the object's internal values when being cleared. obj.__dict__.clear() now clears the internal values, but leaves the dict attached to the object.

  • gh-117431: Improve the performance of the following bytes and bytearray methods by adapting them to the METH_FASTCALL calling convention:

    • count()

    • find()

    • index()

    • rfind()

    • rindex()

  • gh-117709: Speed up calls to str() with positional-only argument, by using the PEP 590 vectorcall calling convention. Patch by Erlend Aasland.

  • gh-117680: Give _PyInstructionSequence a 哋它亢 interface and use it in tests.

  • gh-115776: Statically allocated objects are, by definition, immortal so must be marked as such regardless of whether they are in extension modules or not.

  • gh-117385: Remove unhandled PY_MONITORING_EVENT_BRANCH and PY_MONITORING_EVENT_EXCEPTION_HANDLED events from sys.settrace().

  • gh-116322: Extension modules may indicate to the runtime that they can run without the GIL. Multi-phase init modules do so by calling providing Py_MOD_GIL_NOT_USED for the Py_mod_gil slot, while single-phase init modules call PyUnstable_Module_SetGIL(mod, Py_MOD_GIL_NOT_USED) from their init function.

  • gh-116129: Implement PEP 696, adding support for defaults on type parameters. Patch by Jelle Zijlstra.

  • gh-93502: Add two new functions to the C-API, PyRefTracer_SetTracer() and PyRefTracer_GetTracer(), that allows to track object creation and destruction the same way the tracemalloc module does. Patch by Pablo Galindo

  • gh-107674: Improved the performance of sys.settrace() significantly

  • gh-95754: Improve the error message when a script shadowing a module from the standard library causes AttributeError to be raised. Similarly, improve the error message when a script shadowing a third party module attempts to access an attribute from that third party module while still initialising.

  • gh-99180: Elide uninformative traceback indicators in return and simple assignment statements. Patch by Pablo Galindo.

  • gh-105879: Allow the globals and locals arguments to exec() and eval() to be passed as keywords.

Library

  • gh-118418: A DeprecationWarning is now emitted if you fail to pass a value to the new type_params parameter of typing._eval_type() or typing.ForwardRef._evaluate(). (Using either of these private and undocumented functions is discouraged to begin with, but failing to pass a value to the type_params parameter may lead to incorrect behaviour on 哋它亢 3.12 or newer.)

  • gh-118660: Add an optional second type parameter to typing.ContextManager and typing.AsyncContextManager, representing the return types of __exit__() and __aexit__() respectively. This parameter defaults to bool | None.

  • gh-118650: The enum module allows method named _repr_* to be defined on Enum types.

  • gh-118648: Add type parameter defaults to typing.Generator and typing.AsyncGenerator.

  • gh-101137: Mime type text/x-rst is now supported by mimetypes.

  • gh-118164: The 哋它亢 implementation of the decimal module could appear to hang in relatively small power cases (like 2**117) if context precision was set to a very high value. A different method to check for exactly representable results is used now that doesn't rely on computing 10**precision (which could be effectively too large to compute).

  • gh-111744: breakpoint() and pdb.set_trace() now enter the debugger immediately after the call rather than before the next line is executed.

  • gh-118500: Add pdb support for zipapps

  • gh-118406: Add signature for sqlite3.Connection objects.

  • gh-101732: Use a Y2038 compatible openssl time function when available.

  • gh-118404: Fix inspect.signature() for non-comparable callables.

  • gh-118402: Fix inspect.signature() for the result of the functools.cmp_to_key() call.

  • gh-116622: On Android, sysconfig.get_platform now returns the format specified by PEP 738.

  • gh-118285: Allow to specify the signature of custom callable instances of extension type by the __text_signature__ attribute. Specify signatures of operator.attrgetter, operator.itemgetter, and operator.methodcaller instances.

  • gh-118314: Fix an edge case in binascii.a2b_base64() strict mode, where excessive padding is not detected when no padding is necessary.

  • gh-118271: Add the PhotoImage methods read() to read an image from a file and data() to get the image data. Add background and grayscale parameters to PhotoImage method write().

  • gh-118225: Add the PhotoImage method copy_replace() to copy a region from one image to other image, possibly with pixel zooming and/or subsampling. Add from_coords parameter to PhotoImage methods copy(), zoom() and subsample(). Add zoom and subsample parameters to PhotoImage method copy().

  • gh-118221: Fix a bug where sqlite3.Connection.iterdump() could fail if a custom row factory was used. Patch by Erlend Aasland.

  • gh-118013: Fix regression introduced in gh-103193 that meant that calling inspect.getattr_static() on an instance would cause a strong reference to that instance's class to persist in an internal cache in the inspect module. This caused unexpected memory consumption if the class was dynamically created, the class held strong references to other objects which took up a significant amount of memory, and the cache contained the sole strong reference to the class. The fix for the regression leads to a slowdown in getattr_static(), but the function should still be significantly faster than it was in 哋它亢 3.11. Patch by Alex Waygood.

  • gh-118218: Speed up itertools.pairwise() in the common case by up to 1.8x.

  • gh-117486: Improve the behavior of user-defined subclasses of ast.AST. Such classes will now require no changes in the usual case to conform with the behavior changes of the ast module in 哋它亢 3.13. Patch by Jelle Zijlstra.

  • gh-90848: Fixed unittest.mock.create_autospec() to configure parent mock with keyword arguments.

  • gh-118168: Fix incorrect argument substitution when typing.Unpack is used with the builtin tuple. typing.Unpack now raises TypeError when used with certain invalid types. Patch by Jelle Zijlstra.

  • gh-118131: Add command-line interface for the random module. Patch by Hugo van Kemenade.

  • gh-118107: Fix zipimport reading of ZIP64 files with file entries that are too big or offset too far.

  • gh-102511: Fix os.path.normpath() for UNC paths on Windows. Speed up os.path.splitroot() with a native implementation.

  • gh-117535: Change the unknown filename of warnings from sys to <sys> to clarify that it's not a real filename.

  • gh-114053: Fix erroneous NameError when calling typing.get_type_hints() on a class that made use of PEP 695 type parameters in a module that had from __future__ import annotations at the top of the file. Patch by Alex Waygood.

  • gh-116931: Add parameter fileobj check for tarfile.TarFile.addfile()

  • gh-117995: Don't raise DeprecationWarning when a sequence of parameters is used to bind indexed, nameless placeholders. See also gh-100668.

  • gh-80361: Fix TypeError in email.message.Message.get_payload() when the charset is RFC 2231 encoded.

  • gh-86650: Fix IndexError when parse some emails with invalid Message-ID (including one-off addresses generated by Microsoft Outlook).

  • gh-117691: Improve the error messages emitted by tarfile deprecation warnings relating to PEP 706. If a filter argument is not provided to extract() or extractall, the deprecation warning now points to the line in the user's code where the relevant function was called. Patch by Alex Waygood.

  • gh-115874: Fixed a possible segfault during garbage collection of _asyncio.FutureIter objects. Patch by Savannah Ostrowski.

  • gh-115060: Speed up pathlib.Path.glob() by omitting an initial is_dir() call. As a result of this change, glob() can no longer raise OSError.

  • gh-77102: site module now parses .pth file with UTF-8 first, and locale encoding if UnicodeDecodeError happened. It supported only locale encoding before.

  • gh-76785: We've exposed the low-level _interpreters module for the sake of the PyPI implementation of PEP 734. It was sometimes available as the _xxsubinterpreters module and was formerly used only for testing. For the most part, it should be considered an internal module, like _thread and _imp. See https://discuss.python.org/t/pep-734-multiple-interpreters-in-the-stdlib/41147/26.

  • gh-115060: Speed up pathlib.Path.glob() by not scanning directories for non-wildcard pattern segments.

  • gh-117727: Speed up pathlib.Path.iterdir() by using os.scandir() internally.

  • gh-117586: Speed up pathlib.Path.walk() by working with strings internally.

  • gh-117722: Change the new multi-separator support in asyncio.StreamReader.readuntil() to only accept tuples of separators rather than arbitrary iterables.

  • gh-117692: Fixes a bug when doctest.DocTestFinder was failing on wrapped builtin_function_or_method.

  • gh-117348: Largely restored import time performance of configparser by avoiding dataclasses.

  • gh-117641: Speedup os.path.commonpath() on Unix.

  • gh-117663: Fix _simple_enum to detect aliases when multiple arguments are present but only one is the member value.

  • gh-117636: Speedup os.path.join().

  • gh-117618: Support package.module as filename for break command of pdb

  • gh-102247: the status codes enum with constants in http.HTTPStatus are updated to include the names from RFC9110. This RFC includes some HTTP statuses previously only used for WEBDAV and assigns more generic names to them.

    The old constants are preserved for backwards compatibility.

  • gh-117607: Speedup os.path.relpath().

  • gh-117586: Speed up pathlib.Path.glob() by working with strings internally.

  • gh-117225: Add colour to doctest output. Patch by Hugo van Kemenade.

  • gh-117566: ipaddress.IPv6Address.is_loopback() will now return True for IPv4-mapped loopback addresses, i.e. addresses in the ::ffff:127.0.0.0/104 address space.

  • gh-117546: Fix issue where os.path.realpath() stopped resolving symlinks after encountering a symlink loop on POSIX.

  • gh-116720: Improved behavior of asyncio.TaskGroup when an external cancellation collides with an internal cancellation. For example, when two task groups are nested and both experience an exception in a child task simultaneously, it was possible that the outer task group would misbehave, because its internal cancellation was swallowed by the inner task group.

    In the case where a task group is cancelled externally and also must raise an ExceptionGroup, it will now call the parent task's cancel() method. This ensures that a asyncio.CancelledError will be raised at the next await, so the cancellation is not lost.

    An added benefit of these changes is that task groups now preserve the cancellation count (asyncio.Task.cancelling()).

    In order to handle some corner cases, asyncio.Task.uncancel() may now reset the undocumented _must_cancel flag when the cancellation count reaches zero.

  • gh-117516: Add typing.TypeIs, implementing PEP 742. Patch by Jelle Zijlstra.

  • gh-117503: Fix support of non-ASCII user names in bytes paths in os.path.expanduser() on Posix.

  • gh-117394: os.path.ismount() is now 2-3 times faster if the user has permissions.

  • gh-117313: Only treat '\n', '\r' and '\r\n' as line separators in re-folding the email messages. Preserve control characters '\v', '\f', '\x1c', '\x1d' and '\x1e' and Unicode line separators '\x85', '\u2028' and '\u2029' as is.

  • gh-117142: Convert _ctypes to multi-phase initialisation (PEP 489).

  • gh-66543: Add the mimetypes.guess_file_type() function which works with file path. Passing file path instead of URL in guess_type() is soft deprecated.

  • gh-68583: webbrowser CLI: replace getopt with argparse, add long options. Patch by Hugo van Kemenade.

  • gh-116871: Name suggestions for AttributeError and ImportError now only include underscored names if the original name was underscored.

  • gh-116023: Don't show empty fields (value None or []) in ast.dump() by default. Add show_empty=False parameter to optionally show them.

  • gh-115961: Added name and mode attributes for compressed and archived file-like objects in modules bz2, lzma, tarfile and zipfile. The value of the mode attribute of gzip.GzipFile was changed from integer (1 or 2) to string ('rb' or 'wb'). The value of the mode attribute of the readable file-like object returned by zipfile.ZipFile.open() was changed from 'r' to 'rb'.

  • gh-82062: Fix inspect.signature() to correctly handle parameter defaults on methods in extension modules that use names defined in the module namespace.

  • gh-83856: Honor atexit for all multiprocessing start methods

  • gh-113081: Print colorized exception just like built-in traceback in pdb

  • gh-112855: Speed up pickling of pathlib.PurePath objects. Patch by Barney Gale.

  • gh-111744: Support opcode events in bdb

  • gh-109617: ncurses: fixed a crash that could occur on macOS 13 or earlier when 哋它亢 was built with Apple Xcode 15's SDK.

  • gh-83151: Enabled arbitrary statements and evaluations in pdb shell to access the local variables of the current frame, which made it possible for multi-scope code like generators or nested function to work.

  • gh-110209: Add __class_getitem__() to types.GeneratorType and types.CoroutineType for type hinting purposes. Patch by James Hilton-Balfe.

  • gh-108191: The types.SimpleNamespace now accepts an optional positional argument which specifies initial values of attributes as a dict or an iterable of key-value pairs.

  • gh-62090: Fix assertion errors caused by whitespace in metavars or SUPPRESS-ed groups in argparse by simplifying usage formatting. Patch by Ali Hamdan.

  • gh-102402: Adjust logging.LogRecord to use time.time_ns() and fix minor bug related to floating-point math.

  • gh-100242: Bring pure 哋它亢 implementation functools.partial.__new__ more in line with the C-implementation by not just always checking for the presence of the attribute 'func' on the first argument of partial. Instead, both the 哋它亢 version and the C version perform an isinstance(func, partial) check on the first argument of partial.

  • gh-99730: HEAD requests are no longer upgraded to GET request during redirects in urllib.

  • gh-66410: Setting the tkinter module global wantobjects to 2 before creating the Tk object or call the wantobjects() method of the Tk object with argument 2 makes now arguments to callbacks registered in the tkinter module to be passed as various 哋它亢 objects (int, float, bytes, tuple), depending on their internal representation in Tcl, instead of always str. tkinter.wantobjects is now set to 2 by default.

  • bpo-40943: Fix several IndexError when parse emails with truncated Message-ID, address, routes, etc, e.g. example@.

  • bpo-39324: Add mime type mapping for .md <-> text/markdown

  • bpo-18108: shutil.chown() now supports dir_fd and follow_symlinks keyword arguments.

  • bpo-30988: Fix parsing of emails with invalid address headers having a leading or trailing dot. Patch by tsufeki.

  • bpo-32839: Add the after_info() method for Tkinter widgets.

Documentation

  • gh-117928: The minimum Sphinx version required for the documentation is now 6.2.1.

Build

  • gh-118734: Fixes Windows build when invoked directly (not through the build.bat script) without specifying a value for UseTIER2.

  • gh-115119: The configure option --with-system-libmpdec now defaults to yes. The bundled copy of libmpdecimal will be removed in 哋它亢 3.15.

  • gh-117845: Fix building against recent libedit versions by detecting readline hook signatures in configure.

  • gh-116622: A testbed project was added to run the test suite on Android.

  • gh-117645: Increase WASI stack size from 512 KiB to 8 MiB and the initial memory from 10 MiB to 20 MiB. Patch by Victor Stinner.

  • gh-115119: configure now uses pkg-config to detect decimal dependencies if the --with-system-libmpdec option is given.

Windows

  • gh-115119: Update Windows installer to use libmpdecimal 4.0.0.

  • gh-118486: os.mkdir() now accepts mode of 0o700 to restrict the new directory to the current user.

  • gh-118347: Fixes launcher updates not being installed.

  • gh-118293: The multiprocessing module now passes the STARTF_FORCEOFFFEEDBACK flag when spawning processes to tell Windows not to change the mouse cursor.

  • gh-115009: Update Windows installer to use SQLite 3.45.3.

  • gh-90329: Suppress the warning displayed on virtual environment creation when the requested and created paths differ only by a short (8.3 style) name. Warnings will continue to be shown if a junction or symlink in the path caused the venv to be created in a different location than originally requested.

  • gh-117786: Fixes virtual environments not correctly launching when created from a Store install.

macOS

  • gh-115119: Update macOS installer to use libmpdecimal 4.0.0.

  • gh-114099: iOS preprocessor symbol usage was made compatible with older macOS SDKs.

  • gh-115009: Update macOS installer to use SQLite 3.45.3.

  • gh-91629: Use ~/.config/fish/conf.d configs and fish_add_path to set PATH when installing for the Fish shell.

IDLE

  • bpo-34774: Use user-selected color theme for Help => IDLE Doc.

C API

哋它亢 3.13.0 alpha 6

Release date: 2024-04-09

Core and Builtins

  • gh-117494: Refactored the instruction sequence data structure out of compile.c into instruction_sequence.c.

  • gh-116968: Introduce a unified 16-bit backoff counter type (_Py_BackoffCounter), shared between the Tier 1 adaptive specializer and the Tier 2 optimizer. The API used for adaptive specialization counters is changed but the behavior is (supposed to be) identical.

    The behavior of the Tier 2 counters is changed:

    • There are no longer dynamic thresholds (we never varied these).

    • All counters now use the same exponential backoff.

    • The counter for JUMP_BACKWARD starts counting down from 16.

    • The temperature in side exits starts counting down from 64.

  • gh-117431: Improve the performance of the following bytes and bytearray methods by adapting them to the METH_FASTCALL calling convention:

    • endswith()

    • startswith()

  • gh-117431: Improve the performance of the following str methods by adapting them to the METH_FASTCALL calling convention:

  • gh-117411: Move PyFutureFeatures to an internal header and make it private.

  • gh-109120: Added handle of incorrect star expressions, e.g f(3, *). Patch by Grigoryev Semyon

  • gh-117266: Fix crashes for certain user-created subclasses of ast.AST. Such classes are now expected to set the _field_types attribute.

  • gh-99108: Updated the hashlib built-in HACL* project C code from upstream that we use for many implementations when they are not present via OpenSSL in a given build. This also avoids the rare potential for a C symbol name one definition rule linking issue.

  • gh-117108: Change the old space bit of objects in the young generation from 0 to gcstate->visited, so that any objects created during GC will have the old bit set correctly if they get moved into the old generation.

  • gh-117108: The cycle GC now chooses the size of increments based on the total heap size, instead of the rate of object creation. This ensures that it can keep up with growing heaps.

  • gh-116735: For INSTRUMENTED_CALL_FUNCTION_EX, set arg0 to sys.monitoring.MISSING instead of None for CALL event.

  • gh-113964: Starting new threads and process creation through os.fork() are now only prevented once all non-daemon threads exit.

  • gh-116626: Ensure INSTRUMENTED_CALL_FUNCTION_EX always emits CALL

  • gh-116554: list.sort() now exploits more cases of partial ordering, particularly those with long descending runs with sub-runs of equal values. Those are recognized as single runs now (previously, each block of repeated values caused a new run to be created).

  • gh-114099: Added a Loader that can discover extension modules in an iOS-style Frameworks folder.

  • gh-115775: Compiler populates the new __static_attributes__ field on a class with the names of attributes of this class which are accessed through self.X from any function in its body.

  • gh-115776: The array of values, the PyDictValues struct is now embedded in the object during allocation. This provides better performance in the common case, and does not degrade as much when the object's __dict__ is materialized.

  • gh-108362: Implement an incremental cyclic garbage collector. By collecting the old generation in increments, there is no need for a full heap scan. This can hugely reduce maximum pause time for programs with large heaps.

    Reduce the number of generations from three to two. The old generation is split into two spaces, "visited" and "pending".

    Collection happens in two steps:: * An increment is formed from the young generation and a small part of the pending space. * This increment is scanned and the survivors moved to the end of the visited space.

    When the collecting space becomes empty, the two spaces are swapped.

  • gh-109870: Dataclasses now calls exec() once per dataclass, instead of once per method being added. This can speed up dataclass creation by up to 20%.

  • gh-97901: Mime type text/rtf is now supported by mimetypes.

  • bpo-24612: Improve the SyntaxError that happens when 'not' appears after an operator. Patch by Pablo Galindo

Library

  • gh-117648: Improve performance of os.path.join() and os.path.expanduser().

  • gh-117584: Raise TypeError for non-paths in posixpath.relpath().

  • gh-117467: Preserve mailbox ownership when rewriting in mailbox.mbox.flush(). Patch by Tony Mountifield.

  • gh-114848: Raise FileNotFoundError when getcwd() returns '(unreachable)', which can happen on Linux >= 2.6.36 with glibc < 2.27.

  • gh-117459: asyncio.asyncio.run_coroutine_threadsafe() now keeps the traceback of CancelledError, TimeoutError and InvalidStateError which are raised in the coroutine.

  • gh-117381: Fix error message for ntpath.commonpath().

  • gh-117337: Deprecate undocumented glob.glob0() and glob.glob1() functions. Use glob.glob() and pass a directory to its root_dir argument instead.

  • gh-117349: Optimise several functions in os.path.

  • gh-117348: Refactored configparser.RawConfigParser._read() to reduce cyclometric complexity and improve comprehensibility.

  • gh-117335: Raise TypeError for non-sequences for ntpath.commonpath().

  • gh-66449: configparser.ConfigParser now accepts unnamed sections before named ones, if configured to do so.

  • gh-88014: In documentation of gzip.GzipFile in module gzip, explain data type of optional constructor argument mtime, and recommend mtime = 0 for generating deterministic streams.

  • gh-117310: Fixed an unlikely early & extra Py_DECREF triggered crash in ssl when creating a new _ssl._SSLContext if C哋它亢 was built implausibly such that the default cipher list is empty or the SSL library it was linked against reports a failure from its C SSL_CTX_set_cipher_list() API.

  • gh-117294: A DocTestCase now reports as skipped if all examples in the doctest are skipped.

  • gh-98966: In subprocess, raise a more informative message when stdout=STDOUT.

  • gh-117225: doctest: only print "and X failed" when non-zero, don't pluralise "1 items". Patch by Hugo van Kemenade.

  • gh-117205: Speed up compileall.compile_dir() by 20% when using multiprocessing by increasing chunksize.

  • gh-117178: Fix regression in lazy loading of self-referential modules, introduced in gh-114781.

  • gh-112383: Fix dis module's handling of ENTER_EXECUTOR instructions.

  • gh-117182: Lazy-loading of modules that modify their own __class__ no longer reverts the __class__ to types.ModuleType.

  • gh-117084: Fix zipfile extraction for directory entries with the name containing backslashes on Windows.

  • gh-117114: Make os.path.isdevdrive() available on all platforms. For those that do not offer Dev Drives, it will always return False.

  • gh-117110: Fix a bug that prevents subclasses of typing.Any to be instantiated with arguments. Patch by Chris Fu.

  • gh-109653: Deferred select imports in importlib.metadata and importlib.resources for a 14% speedup.

  • gh-70647: Start the deprecation period for the current behavior of datetime.datetime.strptime() and time.strptime() which always fails to parse a date string with a ValueError involving a day of month such as strptime("02-29", "%m-%d") when a year is not specified and the date happen to be February 29th. This should help avoid users finding new bugs every four years due to a natural mistaken assumption about the API when parsing partial date values.

  • gh-116987: Fixed inspect.findsource() for class code objects.

  • gh-114099: Modify standard library to allow for iOS platform differences.

  • gh-90872: On Windows, subprocess.Popen.wait() no longer calls WaitForSingleObject() with a negative timeout: pass 0 ms if the timeout is negative. Patch by Victor Stinner.

  • gh-116957: configparser: Don't leave ConfigParser values in an invalid state (stored as a list instead of a str) after an earlier read raised DuplicateSectionError or DuplicateOptionError.

  • gh-115538: _io.WindowsConsoleIO now emit a warning if a boolean value is passed as a filedescriptor argument.

  • gh-90095: Ignore empty lines and comments in .pdbrc

  • gh-106531: Refreshed zipfile._path from zipp 3.18, providing better compatibility for PyPy, better glob performance for deeply nested zipfiles, and providing internal access to CompleteDirs.inject for use in other tests (like importlib.resources).

  • gh-63207: On Windows, time.time() now uses the GetSystemTimePreciseAsFileTime() clock to have a resolution better than 1 us, instead of the GetSystemTimeAsFileTime() clock which has a resolution of 15.6 ms. Patch by Victor Stinner.

  • gh-116764: Restore support of None and other false values in urllib.parse functions parse_qs() and parse_qsl(). Also, they now raise a TypeError for non-zero integers and non-empty sequences.

  • gh-116811: In PathFinder.invalidate_caches, delegate to MetadataPathFinder.invalidate_caches.

  • gh-116647: Fix recursive child in dataclasses

  • gh-113171: Fixed various false positives and false negatives in

    Also in the corresponding ipaddress.IPv4Network and ipaddress.IPv6Network attributes.

  • gh-63283: In encodings.idna, any capitalization of the the ACE prefix (xn--) is now acceptable. Patch by Pepijn de Vos and Zackery Spytz.

  • gh-71042: Add platform.android_ver(), which provides device and OS information on Android.

  • gh-73468: Added new math.fma() function, wrapping C99's fma() operation: fused multiply-add function. Patch by Mark Dickinson and Victor Stinner.

  • gh-116608: The importlib.resources functions is_resource(), open_binary(), open_text(), path(), read_binary(), and read_text() are un-deprecated, and support subdirectories via multiple positional arguments. The contents() function also allows subdirectories, but remains deprecated.

  • gh-116484: Change automatically generated tkinter.Checkbutton widget names to avoid collisions with automatically generated tkinter.ttk.Checkbutton widget names within the same parent widget.

  • gh-114314: In ctypes, ctype data is now stored in type objects directly rather than in a dict subclass. This is an internal change that should not affect usage.

  • gh-116401: Fix blocking os.fwalk() and shutil.rmtree() on opening named pipe.

  • gh-71052: Implement ctypes.util.find_library() on Android.

  • gh-90535: Fix support of interval values > 1 in logging.TimedRotatingFileHandler for when='MIDNIGHT' and when='Wx'.

  • gh-113308: Remove some internal protected parts from uuid: _has_uuid_generate_time_safe, _netbios_getnode, _ipconfig_getnode, and _load_system_functions. They were unused.

  • gh-115627: Fix the ssl module error handling of connection terminate by peer. It now throws an OSError with the appropriate error code instead of an EOFError.

  • gh-114847: Speed up os.path.realpath() on non-Windows platforms.

  • gh-114271: Fix a race in threading.Thread.join().

    threading._MainThread now always represents the main thread of the main interpreter.

    PyThreadState.on_delete and PyThreadState.on_delete_data have been removed.

  • gh-113538: Add asyncio.Server.close_clients() and asyncio.Server.abort_clients() methods which allow to more forcefully close an asyncio server.

  • gh-85287: Changes Unicode codecs to return UnicodeEncodeError or UnicodeDecodeError, rather than just UnicodeError.

  • gh-113548: pdb now allows CLI arguments to pdb -m.

  • gh-112948: Make completion of pdb similar to 哋它亢 REPL

  • gh-105866: Fixed _get_slots bug which caused error when defining dataclasses with slots and a weakref_slot.

  • gh-96471: Add asyncio.Queue termination with shutdown() method.

  • gh-89739: The zipimport module can now read ZIP64 files.

  • bpo-33533: asyncio.as_completed() now returns an object that is both an asynchronous iterator and plain iterator. The new asynchronous iteration pattern allows for easier correlation between prior tasks and their completed results. This is a closer match to concurrent.futures.as_completed()'s iteration pattern. Patch by Justin Arthur.

  • bpo-27578: inspect.getsource() (and related functions) work with empty module files, returning '\n' (or reasonable equivalent) instead of raising OSError. Patch by Kernc.

  • bpo-37141: Accept an iterable of separators in asyncio.StreamReader.readuntil(), stopping when one of them is encountered.

  • gh-66543: Make mimetypes.guess_type() properly parsing of URLs with only a host name, URLs containing fragment or query, and filenames with only a UNC sharepoint on Windows. Based on patch by Dong-hee Na.

  • bpo-15010: unittest.TestLoader.discover() now saves the original value of unittest.TestLoader._top_level_dir and restores it at the end of the call.

Documentation

  • gh-115977: Remove compatibility references to Emscripten.

  • gh-114099: Add an iOS platform guide, and flag modules not available on iOS.

  • gh-91565: Changes to documentation files and config outputs to reflect the new location for reporting bugs - i.e. GitHub rather than datacon-14302.xyz.

Tests

  • gh-83434: Disable JUnit XML output (--junit-xml=FILE command line option) in regrtest when hunting for reference leaks (-R option). Patch by Victor Stinner.

  • gh-117187: Fix XML tests for vanilla Expat <2.6.0.

  • gh-116333: Tests of TLS related things (error codes, etc) were updated to be more lenient about specific error message strings and behaviors as seen in the BoringSSL and AWS-LC forks of OpenSSL.

  • gh-117089: Consolidated tests for importlib.metadata in their own metadata package.

  • gh-115979: Update test_importlib so that it passes under WASI SDK 21.

  • gh-112536: Add --tsan to test.regrtest for running TSAN tests in reasonable execution times. Patch by Donghee Na.

  • gh-116307: Added import helper isolated_modules as CleanImport does not remove modules imported during the context. Use it in importlib.resources tests to avoid leaving mod around to impede importlib.metadata tests.

Build

  • gh-114736: Have WASI builds use WASI SDK 21.

  • gh-115983: Skip building test modules that must be built as shared under WASI.

  • gh-71052: Add Android build script and instructions.

Windows

  • gh-117267: Ensure DirEntry.stat().st_ctime behaves consistently with os.stat() during the deprecation period of st_ctime by containing the same value as st_birthtime. After the deprecation period, st_ctime will be the metadata change time (or unavailable through DirEntry), and only st_birthtime will contain the creation time.

  • gh-116195: Improves performance of os.getppid() by using an alternate system API when available. Contributed by vxiiduu.

  • gh-88494: On Windows, time.monotonic() now uses the QueryPerformanceCounter() clock to have a resolution better than 1 us, instead of the GetTickCount64() clock which has a resolution of 15.6 ms. Patch by Victor Stinner.

  • gh-116773: Fix instances of <_overlapped.Overlapped object at 0xXXX> still has pending operation at deallocation, the process may crash.

  • gh-91227: Fix the asyncio ProactorEventLoop implementation so that sending a datagram to an address that is not listening does not prevent receiving any more datagrams.

  • gh-115119: Switched from vendored libmpdecimal code to a separately-hosted external package in the c哋它亢-source-deps repository when building the _decimal module.

C API

  • gh-117642: Fix PEP 737 implementation for %#T and %#N.

  • gh-87193: _PyBytes_Resize() can now be called for bytes objects with reference count > 1, including 1-byte bytes objects. It creates a new bytes object and destroys the old one if it has reference count > 1.

  • gh-117021: Fix integer overflow in PyLong_AsPid() on non-Windows 64-bit platforms.

  • gh-115756: PyCode_GetFirstFree() is an ustable API now and has been renamed to PyUnstable_Code_GetFirstFree(). (Contributed by Bogdan Romanyuk in gh-115781)

  • gh-116869: Add test_cext test: build a C extension to check if the 哋它亢 C API emits C compiler warnings. Patch by Victor Stinner.

  • gh-116869: Make the C API compatible with -Werror=declaration-after-statement compiler flag again. Patch by Victor Stinner.

  • gh-116936: Add PyType_GetModuleByDef() to the limited C API. Patch by Victor Stinner.

  • gh-116809: Restore removed private _PyErr_ChainExceptions1() function. Patch by Victor Stinner.

  • gh-115754: In the limited C API version 3.13, getting Py_None, Py_False, Py_True, Py_Ellipsis and Py_NotImplemented singletons is now implemented as function calls at the stable ABI level to hide implementation details. Getting these constants still return borrowed references. Patch by Victor Stinner.

  • gh-115754: Add Py_GetConstant() and Py_GetConstantBorrowed() functions to get constants. For example, Py_GetConstant(Py_CONSTANT_ZERO) returns a strong reference to the constant zero. Patch by Victor Stinner.

  • gh-111696: Add support for %T, %T#, %N and %N# formats to PyUnicode_FromFormat(): format the fully qualified name of an object type and of a type: call PyType_GetModuleName(). See PEP 737 for more information. Patch by Victor Stinner.

  • gh-111696: Add PyType_GetModuleName() function to get the type's module name. Equivalent to getting the type.__module__ attribute. Patch by Eric Snow and Victor Stinner.

  • gh-111696: Add PyType_GetFullyQualifiedName() function to get the type's fully qualified name. Equivalent to f"{type.__module__}.{type.__qualname__}", or type.__qualname__ if type.__module__ is not a string or is equal to "builtins". Patch by Victor Stinner.

  • gh-85283: The fcntl, grp, pwd, termios, _statistics and _testconsole C extensions are now built with the limited C API. Patch by Victor Stinner.

  • gh-111140: Add additional flags to PyLong_AsNativeBytes() and PyLong_FromNativeBytes() to allow the caller to determine how to handle edge cases around values that fill the entire buffer.

  • gh-113024: Add PyObject_GenericHash() function.

哋它亢 3.13.0 alpha 5

Release date: 2024-03-12

Security

Core and Builtins

  • gh-116604: Respect the status of the garbage collector when indirect calls are made via PyErr_CheckSignals() and the evaluation breaker. Patch by Pablo Galindo

  • gh-112087: list is now compatible with the implementation of PEP 703.

  • gh-116381: Add specialization for CONTAINS_OP.

  • gh-116296: Fix possible refleak in object.__reduce__() internal error handling.

  • gh-115823: Properly calculate error ranges in the parser when raising SyntaxError exceptions caused by invalid byte sequences. Patch by Pablo Galindo

  • gh-115778: Add tierN annotation for instruction definition in interpreter DSL.

  • gh-115733: Fix crash when calling next() on exhausted list iterators.

  • gh-115700: The regen-cases build stage now works on Windows.

  • gh-115347: Fix bug where docstring was replaced by a redundant NOP when 哋它亢 is run with -OO.

  • gh-115323: Make error message more meaningful for when bytearray.extend() is called with a str object.

  • gh-112175: Every PyThreadState now has its own eval_breaker, allowing specific threads to be interrupted.

  • gh-115154: Fix a bug that was causing the tokenize.untokenize() function to handle unicode named literals incorrectly. Patch by Pablo Galindo

  • gh-112433: Add ability to force alignment of ctypes.Structure by way of the new _align_ attribute on the class.

  • gh-104090: The multiprocessing resource tracker now exits with non-zero status code if a resource leak was detected. It still exits with status code 0 otherwise.

  • gh-105858: Improve the constructors for ast nodes. Arguments of list types now default to an empty list if omitted, and optional fields default to None. AST nodes now have an __annotations__ attribute with the expected types of their attributes. Passing unrecognized extra arguments to AST nodes is deprecated and will become an error in 哋它亢 3.15. Omitting a required argument to an AST node is deprecated and will become an error in 哋它亢 3.15. Patch by Jelle Zijlstra.

  • gh-101860: Expose __name__ attribute on property.

  • gh-96497: Fix incorrect resolution of mangled class variables used in assignment expressions in comprehensions.

Library

  • gh-116600: Fix repr() for global Flag members.

  • gh-116349: platform.java_ver() is deprecated and will be removed in 3.15. It was largely untested, had a confusing API, and was only useful for Jython support.

  • gh-116143: Fix a race in pydoc _start_server, eliminating a window in which _start_server can return a thread that is "serving" but without a docserver set.

  • gh-116127: typing: implement PEP 705 which adds typing.ReadOnly support to typing.TypedDict.

  • gh-116325: typing: raise SyntaxError instead of AttributeError on forward references as empty strings.

  • gh-115957: When asyncio.TaskGroup.create_task is called on an inactive asyncio.TaskGroup, the given coroutine will be closed (which prevents a RuntimeWarning).

  • gh-115978: Disable preadv(), readv(), pwritev(), and writev() on WASI.

    Under wasmtime for WASI 0.2, these functions don't pass test_posix (https://github.com/bytecodealliance/wasmtime/issues/7830).

  • gh-88352: Fix the computation of the next rollover time in the logging.TimedRotatingFileHandler handler. computeRollover() now always returns a timestamp larger than the specified time and works correctly during the DST change. doRollover() no longer overwrite the already rolled over file, saving from data loss when run at midnight or during repeated time at the DST change.

  • gh-87115: Set __main__.__spec__ to None when running a script with pdb

  • gh-76511: Fix UnicodeEncodeError in email.Message.as_string() that results when a message that claims to be in the ascii character set actually has non-ascii characters. Non-ascii characters are now replaced with the U+FFFD replacement character, like in the replace error handler.

  • gh-89547: Add support for nested typing special forms like Final[ClassVar[int]].

  • gh-65824: Improve the less prompt in pydoc.

  • gh-116040: [Enum] fix by-value calls when second value is falsey; e.g. Cardinal(1, 0)

  • gh-115821: [Enum] Improve error message when calling super().__new__() in custom __new__.

  • gh-85644: Use the XDG_CURRENT_DESKTOP environment variable in webbrowser to check desktop. Prefer it to the deprecated GNOME_DESKTOP_SESSION_ID for GNOME detection.

  • gh-75988: Fixed unittest.mock.create_autospec() to pass the call through to the wrapped object to return the real result.

  • gh-115881: Fix issue where ast.parse() would incorrectly flag conditional context managers (such as with (x() if y else z()): ...) as invalid syntax if feature_version=(3, 8) was passed. This reverts changes to the grammar made as part of gh-94949.

  • gh-115886: Fix silent truncation of the name with an embedded null character in multiprocessing.shared_memory.SharedMemory.

  • gh-115532: Add kernel density estimation to the statistics module.

  • gh-115714: On WASI, the time module no longer get process time using times() or CLOCK_PROCESS_CPUTIME_ID, system API is that is unreliable and is likely to be removed from WASI. The affected clock functions fall back to calling clock().

  • gh-115809: Improve algorithm for computing which rolled-over log files to delete in logging.TimedRotatingFileHandler. It is now reliable for handlers without namer and with arbitrary deterministic namer that leaves the datetime part in the file name unmodified.

  • gh-74668: urllib.parse functions parse_qs() and parse_qsl() now support bytes arguments containing raw and percent-encoded non-ASCII data.

  • gh-67044: csv.writer() now always quotes or escapes '\r' and '\n', regardless of lineterminator value.

  • gh-115712: Restore support of space delimiter with skipinitialspace=True in csv. csv.writer() now quotes empty fields if delimiter is a space and skipinitialspace is true and raises exception if quoting is not possible.

  • gh-112364: Fixed ast.unparse() to handle format_spec with ", ' or \\. Patched by Frank Hoffmann.

  • gh-112997: Stop logging potentially sensitive callback arguments in asyncio unless debug mode is active.

  • gh-114914: Fix an issue where an abandoned StreamWriter would not be garbage collected.

  • gh-111358: Fix a bug in asyncio.BaseEventLoop.shutdown_default_executor() to ensure the timeout passed to the coroutine behaves as expected.

  • gh-115618: Fix improper decreasing the reference count for None argument in property methods getter(), setter() and deleter().

  • gh-112720: Refactor dis.ArgResolver to make it possible to subclass and change the way jump args are interpreted.

  • gh-112006: Fix inspect.unwrap() for types with the __wrapper__ data descriptor. Fix inspect.Signature.from_callable() for builtins classmethod() and staticmethod().

  • gh-101293: Support callables with the __call__() method and types with __new__() and __init__() methods set to class methods, static methods, bound methods, partial functions, and other types of methods and descriptors in inspect.Signature.from_callable().

  • gh-103092: Isolate _lsprof (apply PEP 687).

  • gh-113942: pydoc no longer skips global functions implemented as builtin methods, such as MethodDescriptorType and WrapperDescriptorType.

  • gh-115256: Added DeprecationWarning when accessing the tarfile attribute of TarInfo objects. The attribute is never used internally and is only attached to TarInfos when the tarfile is opened in write-mode, not read-mode. The attribute creates an unnecessary reference cycle which may cause corruption when not closing the handle after writing a tarfile.

  • gh-115197: urllib.request no longer resolves the hostname before checking it against the system's proxy bypass list on macOS and Windows.

  • gh-113812: DatagramTransport.sendto() will now send zero-length datagrams if called with an empty bytes object. The transport flow control also now accounts for the datagram header when calculating the buffer size.

  • gh-114763: Protect modules loaded with importlib.util.LazyLoader from race conditions when multiple threads try to access attributes before the loading is complete.

  • gh-114709: posixpath.commonpath() now raises a ValueError exception when passed an empty iterable. Previously, IndexError was raised.

    posixpath.commonpath() now raises a TypeError exception when passed None. Previously, ValueError was raised.

  • gh-114610: Fix bug where pathlib.PurePath.with_stem() converted a non-empty path suffix to a stem when given an empty stem argument. It now raises ValueError, just like pathlib.PurePath.with_suffix() does when called on a path with an empty stem, given a non-empty suffix argument.

  • gh-107361: Add ssl.VERIFY_X509_PARTIAL_CHAIN and VERIFY_X509_STRICT to the default SSL context created with ssl.create_default_context().

  • gh-112281: Allow creating union of types for typing.Annotated with unhashable metadata.

  • gh-111775: Fix importlib.resources.simple.ResourceHandle.open() for text mode, added missed stream argument.

  • gh-90095: Make .pdbrc and -c work with any valid pdb commands.

  • gh-107625: Raise configparser.ParsingError from read() and read_file() methods of configparser.ConfigParser if a key without a corresponding value is continued (that is, followed by an indented line).

  • gh-107155: Fix incorrect output of help(x) where x is a lambda function, which has an __annotations__ dictionary attribute with a "return" key.

  • gh-57141: Add option for non-shallow comparisons to filecmp.dircmp like filecmp.cmp(). Original patch by Steven Ward. Enhanced by Tobias Rautenkranz

  • gh-69990: Profile.print_stats() has been improved to accept multiple sort arguments. Patched by Chiu-Hsiang Hsu and Furkan Onder.

  • gh-104061: Add socket.SO_BINDTOIFINDEX constant.

  • gh-60346: Fix ArgumentParser inconsistent with parse_known_args.

  • gh-102389: Add windows_31j to aliases for cp932 codec

  • gh-72249: functools.partial`s of :func:`repr() has been improved to include the module name. Patched by Furkan Onder and Anilyka Barry.

  • gh-100985: Update HTTPSConnection to consistently wrap IPv6 Addresses when using a proxy.

  • gh-100884: email: fix misfolding of comma in address-lists over multiple lines in combination with unicode encoding.

  • gh-95782: Fix io.BufferedReader.tell(), io.BufferedReader.seek(), _pyio.BufferedReader.tell(), io.BufferedRandom.tell(), io.BufferedRandom.seek() and _pyio.BufferedRandom.tell() being able to return negative offsets.

  • gh-96310: Fix a traceback in argparse when all options in a mutually exclusive group are suppressed.

  • gh-93205: Fixed a bug in logging.handlers.TimedRotatingFileHandler where multiple rotating handler instances pointing to files with the same name but different extensions would conflict and not delete the correct files.

  • bpo-31116: Add Z85 encoding to base64.

  • bpo-44865: Add missing call to localization function in argparse.

  • bpo-43952: Fix multiprocessing.connection.Listener.accept() to accept empty bytes as authkey. Not accepting empty bytes as key causes it to hang indefinitely.

  • bpo-42125: linecache: get module name from __spec__ if available. This allows getting source code for the __main__ module when a custom loader is used.

  • bpo-41122: Failing to pass arguments properly to functools.singledispatchmethod() now throws a TypeError instead of hitting an index out of bounds internally.

  • bpo-40818: The asyncio REPL now runs sys.__interactivehook__ on startup. The default implementation of sys.__interactivehook__ provides auto-completion to the asyncio REPL. Patch contributed by Rémi Lapeyre.

  • bpo-33775: Add 'default' and 'version' help text for localization in argparse.

Documentation

Tests

  • gh-71052: Add test exclusions to support running the test suite on Android.

  • gh-71052: Enable test_concurrent_futures on platforms that support threading but not multiprocessing.

  • gh-115796: Make '_testinternalcapi.assemble_code_object' construct the exception table for the code object.

  • gh-115720: Leak tests (-R, --huntrleaks) now show a summary of the number of leaks found in each iteration.

  • gh-115122: Add --bisect option to regrtest test runner: run failed tests with test.bisect_cmd to identify failing tests. Patch by Victor Stinner.

  • gh-115596: Fix ProgramPriorityTests in test_os permanently changing the process priority.

  • gh-115556: On Windows, commas passed in arguments to Tools\buildbot\test.bat and PCbuild\\rt.bat are now properly handled.

  • gh-115420: Fix translation of exception handler targets by _testinternalcapi.optimize_cfg.

  • gh-115376: Fix segfault in _testinternalcapi.compiler_codegen on bad input.

Build

  • gh-116313: Get WASI builds to work under wasmtime 18 w/ WASI 0.2/preview2 primitives.

  • gh-71052: Change Android's sys.platform from "linux" to "android".

  • gh-116117: Backport libb2's PR #42 to fix compiling C哋它亢 on 32-bit Windows with clang-cl.

  • gh-71052: Fix several Android build issues

  • gh-114099: A testbed project was added to run the test suite on iOS.

  • gh-115350: Fix building ctypes module with -DWIN32_LEAN_AND_MEAN defined

  • gh-111225: Link extension modules against lib哋它亢 on Android.

  • gh-115737: The install name for lib哋它亢 is now correctly set for non-framework macOS builds.

  • gh-114099: Makefile targets were added to support compiling an iOS-compatible framework build.

Windows

  • gh-116012: Ensure the value of GetLastError() is preserved across GIL operations.

  • gh-115582: Building extensions intended for free-threaded builds of C哋它亢 now require compiling with /DPy_GIL_DISABLED manually when using a regular install. This is expected to change in future releases.

  • gh-115554: The installer now has more strict rules about updating the 适用于Windows的哋它亢启动器. In general, most users only have a single launcher installed and will see no difference. When multiple launchers have been installed, the option to install the launcher is disabled until all but one have been removed. Downgrading the launcher (which was never allowed) is now more obviously blocked.

  • gh-115543: 适用于Windows的哋它亢启动器 can now detect 哋它亢 3.13 when installed from the Microsoft Store, and will install 哋它亢 3.12 by default when PYLAUNCHER_ALLOW_INSTALL is set.

macOS

  • gh-116145: Update macOS installer to Tcl/Tk 8.6.14.

IDLE

  • gh-88516: On macOS show a proxy icon in the title bar of editor windows to match platform behaviour.

Tools/Demos

  • gh-100176: Remove outdated Tools/{io,cc,string}bench

  • bpo-45101: Add consistency in usage message IO between 2 versions of 哋它亢-config.

C API

  • gh-114626: Add again _PyCFunctionFastWithKeywords name, removed in 哋它亢 3.13 alpha 4 by mistake. Keep the old private _PyCFunctionFastWithKeywords name (哋它亢 3.7) as an alias to the new public name PyCFunctionFastWithKeywords (哋它亢 3.13a4). Patch by Victor Stinner.

  • gh-111418: Add PyHASH_MODULUS, PyHASH_BITS, PyHASH_INF and PyHASH_IMAG C macros. Patch by Sergey B Kirpichev.

哋它亢 3.13.0 alpha 4

Release date: 2024-02-15

Security

Core and Builtins

  • gh-112087: For an empty reverse iterator for list will be reduced to reversed(). Patch by Donghee Na

  • gh-114570: Add 哋它亢FinalizationError exception. This exception derived from RuntimeError is raised when an operation is blocked during the 哋它亢 finalization. Patch by Victor Stinner.

  • gh-114695: Add sys._clear_internal_caches(), which clears all internal performance-related caches (and deprecate the less-general sys._clear_type_cache() function).

  • gh-114828: Fix compilation crashes in uncommon code examples using super() inside a comprehension in a class body.

  • gh-112069: Adapt set and frozenset methods to Argument Clinic.

  • gh-115011: Setters for members with an unsigned integer type now support the same range of valid values for objects that has a __index__() method as for int.

  • gh-114887: Changed socket type validation in create_datagram_endpoint() to accept all non-stream sockets. This fixes a regression in compatibility with raw sockets.

  • gh-114944: Fixes a race between PyParkingLot_Park and _PyParkingLot_UnparkAll.

  • gh-113462: Limit the number of versions that a single class can use. Prevents a few wayward classes using up all the version numbers.

  • gh-76763: The chr() builtin function now always raises ValueError for values outside the valid range. Previously it raised OverflowError for very large or small values.

  • gh-114806: No longer specialize calls to classes, if those classes have metaclasses. Fixes bug where the __call__ method of the metaclass was not being called.

  • gh-107944: Improve error message for function calls with bad keyword arguments via getargs

  • gh-112529: The free-threaded build no longer allocates space for the PyGC_Head structure in objects that support cyclic garbage collection. A number of other fields and data structures are used as replacements, including ob_gc_bits, ob_tid, and mimalloc internal data structures.

  • gh-114456: Lower the recursion limit under a debug build of WASI.

  • gh-114083: Compiler applies folding of LOAD_CONST with following instruction in a separate pass before other optimisations. This enables jump threading in certain circumstances.

  • gh-114388: Fix a RuntimeWarning emitted when assign an integer-like value that is not an instance of int to an attribute that corresponds to a C struct member of type T_UINT and T_ULONG. Fix a double RuntimeWarning emitted when assign a negative integer value to an attribute that corresponds to a C struct member of type T_UINT.

  • gh-114265: Compiler propagates line numbers before optimization, leading to more optimization opportunities and removing the need for the guarantee_lineno_for_exits hack.

  • gh-112529: The free-threaded build now has its own thread-safe GC implementation that uses mimalloc to find GC tracked objects. It is non-generational, unlike the existing GC implementation.

  • gh-114050: Fix segmentation fault caused by an incorrect format string in TypeError exception when more than two arguments are passed to int.

  • gh-112354: The END_FOR instruction now pops only one value. This is to better support side exits in loops.

  • gh-113884: Make queue.SimpleQueue thread safe when the GIL is disabled.

  • gh-114058: Implement the foundations of the Tier 2 redundancy eliminator.

  • gh-113939: frame.clear(): Clear frame.f_locals as well, and not only the fast locals. This is relevant once frame.f_locals was accessed, which would contain also references to all the locals.

  • gh-112050: Convert collections.deque to use Argument Clinic.

  • gh-112050: Make methods on collections.deque thread-safe when the GIL is disabled.

  • gh-113464: Add an option (--enable-experimental-jit for configure-based builds or --experimental-jit for PCbuild-based ones) to build an experimental just-in-time compiler, based on copy-and-patch

  • gh-113055: Make interp->obmalloc a pointer. For interpreters that share state with the main interpreter, this points to the same static memory structure. For interpreters with their own obmalloc state, it is heap allocated. Add free_obmalloc_arenas() which will free the obmalloc arenas and radix tree structures for interpreters with their own obmalloc state.

  • gh-55664: Add warning when creating type using a namespace dictionary with non-string keys. Patched by Daniel Urban and Furkan Onder.

  • gh-104530: Use native Win32 condition variables.

Library

  • gh-115392: Fix a bug in doctest where incorrect line numbers would be reported for decorated functions.

  • gh-114563: Fix several format() bugs when using the C implementation of Decimal: * memory leak in some rare cases when using the z format option (coerce negative 0) * incorrect output when applying the z format option to type F (fixed-point with capital NAN / INF) * incorrect output when applying the # format option (alternate form)

  • gh-102840: Fix confused traceback when floordiv, mod, or divmod operations happens between instances of fractions.Fraction and complex.

  • gh-115165: Most exceptions are now ignored when attempting to set the __orig_class__ attribute on objects returned when calling typing generic aliases (including generic aliases created using typing.Annotated). Previously only AttributeError was ignored. Patch by Dave Shawley.

  • gh-112903: Fix "issubclass() arg 1 must be a class" errors in certain cases of multiple inheritance with generic aliases (regression in early 3.13 alpha releases).

  • gh-115133: Fix tests for XMLPullParser with Expat 2.6.0.

  • gh-115059: io.BufferedRandom.read1() now flushes the underlying write buffer.

  • gh-79382: Trailing ** no longer allows to match files and non-existing paths in recursive glob().

  • gh-67837: Avoid race conditions in the creation of directories during concurrent extraction in tarfile and zipfile.

  • gh-115060: Speed up pathlib.Path.glob() by removing redundant regex matching.

  • gh-97928: Partially revert the behavior of tkinter.Text.count(). By default it preserves the behavior of older 哋它亢 versions, except that setting wantobjects to 0 no longer has effect. Add a new parameter return_ints: specifying return_ints=True makes Text.count() always returning the single count as an integer instead of a 1-tuple or None.

  • gh-114628: When csv.Error is raised when handling TypeError, do not print the TypeError traceback.

  • gh-85984: Added _POSIX_VDISABLE from C's <unistd.h> to termios.

  • gh-114965: Update bundled pip to 24.0

  • gh-114959: tarfile no longer ignores errors when trying to extract a directory on top of a file.

  • gh-114894: Add array.array.clear().

  • gh-114071: Support tuple subclasses using auto() for enum member value.

  • gh-109475: Fix support of explicit option value "--" in argparse (e.g. --option=--).

  • gh-49766: Fix date-datetime comparison. Now the special comparison methods like __eq__ and __lt__ return NotImplemented if one of comparands is date and other is datetime instead of ignoring the time part and the time zone or forcefully return "not equal" or raise TypeError. It makes comparison of date and datetime subclasses more symmetric and allows to change the default behavior by overriding the special comparison methods in subclasses.

  • gh-110190: Fix ctypes structs with array on Windows ARM64 platform by setting MAX_STRUCT_SIZE to 32 in stgdict. Patch by Diego Russo

  • gh-114678: Ensure that deprecation warning for 'N' specifier in Decimal format is not raised for cases where 'N' appears in other places in the format specifier. Based on patch by Stefan Krah.

  • gh-70303: Return both files and directories from pathlib.Path.glob() if a pattern ends with "**". Previously only directories were returned.

  • gh-109653: Improve import time of importlib.metadata and email.utils.

  • gh-113280: Fix a leak of open socket in rare cases when error occurred in ssl.SSLSocket creation.

  • gh-77749: email.policy.EmailPolicy.fold() now always encodes non-ASCII characters in headers if utf8 is false.

  • gh-83383: Synchronization of the dbm.dumb database is now no-op if there was no modification since opening or last synchronization. The directory file for a newly created empty dbm.dumb database is now created immediately after opening instead of deferring this until synchronizing or closing.

  • gh-91602: Add filter keyword-only parameter to sqlite3.Connection.iterdump() for filtering database objects to dump. Patch by Mariusz Felisiak.

  • gh-112451: Prohibit subclassing pure-哋它亢 datetime.timezone. This is consistent with C-extension implementation. Patch by Mariusz Felisiak.

  • gh-69893: Add the close() method for the iterator returned by xml.etree.ElementTree.iterparse().

  • gh-109653: Reduce the import time of threading module by ~50%. Patch by Daniel Hollas.

  • gh-114492: Make the result of termios.tcgetattr() reproducible on Alpine Linux. Previously it could leave a random garbage in some fields.

  • gh-114315: Make threading.Lock a real class, not a factory function. Add __new__ to _thread.lock type.

  • gh-100414: Add dbm.sqlite3 as a backend to dbm, and make it the new default dbm backend. Patch by Raymond Hettinger and Erlend E. Aasland.

  • gh-113267: Revert changes in gh-106584 which made calls of TestResult methods startTest() and stopTest() unbalanced.

  • gh-75128: Ignore an OSError in asyncio.BaseEventLoop.create_server() when IPv6 is available but the interface cannot actually support it.

  • gh-114423: _DummyThread entries in threading._active are now automatically removed when the related thread dies.

  • gh-114257: Dismiss the FileNotFound error in ctypes.util.find_library() and just return None on Linux.

  • gh-114321: Expose more platform specific constants in the fcntl module on Linux, macOS, FreeBSD and NetBSD.

  • gh-114328: The tty.setcbreak() and new tty.cfmakecbreak() no longer clears the terminal input ICRLF flag. This fixes a regression introduced in 3.12 that no longer matched how OSes define cbreak mode in their stty(1) manual pages.

  • gh-114281: Remove type hints from Lib/asyncio/staggered.py. The annotations in the typeshed project should be used instead.

  • gh-101438: Avoid reference cycle in ElementTree.iterparse. The iterator returned by ElementTree.iterparse may hold on to a file descriptor. The reference cycle prevented prompt clean-up of the file descriptor if the returned iterator was not exhausted.

  • gh-114198: The signature for the __replace__ method on dataclasses now has the first argument named self, rather than obj.

  • gh-104522: OSError raised when run a subprocess now only has filename attribute set to cwd if the error was caused by a failed attempt to change the current directory.

  • gh-114149: Enum: correctly handle tuple subclasses in custom __new__.

  • gh-83648: Support deprecation of options, positional arguments and subcommands in argparse.

  • gh-114087: Speed up dataclasses.asdict up to 1.35x.

  • gh-109534: Fix a reference leak in asyncio.selector_events.BaseSelectorEventLoop when SSL handshakes fail. Patch contributed by Jamie Phan.

  • gh-79634: Accept path-like objects as patterns in pathlib.Path.glob() and rglob().

  • gh-112202: Ensure that a asyncio.Condition.notify() call does not get lost if the awakened Task is simultaneously cancelled or encounters any other error.

  • gh-113951: Fix the behavior of tag_unbind() methods of tkinter.Text and tkinter.Canvas classes with three arguments. Previously, widget.tag_unbind(tag, sequence, funcid) destroyed the current binding for sequence, leaving sequence unbound, and deleted the funcid command. Now it removes only funcid from the binding for sequence, keeping other commands, and deletes the funcid command. It leaves sequence unbound only if funcid was the last bound command.

  • gh-97959: Fix rendering class methods, bound methods, method and function aliases in pydoc. Class methods no longer have "method of builtins.type instance" note. Corresponding notes are now added for class and unbound methods. Method and function aliases now have references to the module or the class where the origin was defined if it differs from the current. Bound methods are now listed in the static methods section. Methods of builtin classes are now supported as well as methods of 哋它亢 classes.

  • gh-113796: Add more validation checks in the csv.Dialect constructor. ValueError is now raised if the same character is used in different roles.

  • gh-113732: Fix support of QUOTE_NOTNULL and QUOTE_STRINGS in csv.reader().

  • gh-113225: Speed up pathlib.Path.walk() by using os.DirEntry.path where possible.

  • gh-89039: When replace() method is called on a subclass of datetime, date or time, properly call derived constructor. Previously, only the base class's constructor was called.

    Also, make sure to pass non-zero fold values when creating subclasses in various methods. Previously, fold was silently ignored.

  • gh-112919: Speed-up datetime.datetime.replace(), datetime.date.replace() and datetime.time.replace().

  • gh-59013: Set breakpoint on the first executable line of the function, instead of the line of function definition when the user do break func using pdb

  • gh-112343: Improve handling of pdb convenience variables to avoid replacing string contents.

  • gh-112240: Add option to calendar module CLI to specify the weekday to start each week. Patch by Steven Ward.

  • gh-111741: Recognise image/webp as a standard format in the mimetypes module.

  • gh-43457: Fix the tkinter widget method wm_attributes(). It now accepts the attribute name without the minus prefix to get window attributes and allows to specify attributes and values to set as keyword arguments. Add new optional keyword argument return_哋它亢_dict: calling w.wm_attributes(return_哋它亢_dict=True) returns the attributes as a dict instead of a tuple. Calling w.wm_attributes() now returns a tuple instead of string if wantobjects was set to 0.

  • gh-82626: Many functions now emit a warning if a boolean value is passed as a file descriptor argument.

  • gh-111051: Added check for file modification during debugging with pdb

  • gh-110345: Show the Tcl/Tk patchlevel (rather than version) in tkinter._test().

  • gh-38807: Fix race condition in trace. Instead of checking if a directory exists and creating it, directly call os.makedirs() with the kwarg exist_ok=True.

  • gh-75705: Set unixfrom envelope in mailbox.mbox and mailbox.MMDF.

  • gh-106233: Fix stacklevel in InvalidTZPathWarning during zoneinfo module import.

  • gh-105102: Allow ctypes.Union to be nested in ctypes.Structure when the system endianness is the opposite of the classes.

  • gh-104282: Fix null pointer dereference in lzma._decode_filter_properties() due to improper handling of BCJ filters with properties of zero length. Patch by Radislav Chugunov.

  • gh-96471: Add queue.Queue termination with shutdown().

  • gh-101599: Changed argparse flag options formatting to remove redundancy.

  • gh-85984: Add POSIX pseudo-terminal functions os.posix_openpt(), os.grantpt(), os.unlockpt(), and os.ptsname().

  • gh-102512: When os.fork() is called from a foreign thread (aka _DummyThread), the type of the thread in a child process is changed to _MainThread. Also changed its name and daemonic status, it can be now joined.

  • gh-88569: Add os.path.isreserved(), which identifies reserved pathnames such as "NUL", "AUX" and "CON". This function is only available on Windows.

    Deprecate pathlib.PurePath.is_reserved().

  • bpo-38364: The inspect functions isgeneratorfunction, iscoroutinefunction, isasyncgenfunction now support functools.partialmethod wrapped functions the same way they support functools.partial.

Documentation

  • gh-115233: Fix an example for LoggerAdapter in the Logging Cookbook.

  • gh-114123: Move the csv module docstring to the csv module instead of reexporting it from the internal _csv module, and remove __doc__ from csv.__all__.

    Move csv.__version__ to the csv module instead of reexporting it from the internal _csv module, and remove __version__ from csv.__all__.

Tests

  • gh-114099: Added test exclusions required to run the test suite on iOS.

  • gh-105089: Fix test.test_zipfile.test_core.TestWithDirectory.test_create_directory_with_write test in AIX by doing a bitwise AND of 0xFFFF on mode , so that it will be in sync with zinfo.external_attr

Build

  • gh-115167: Avoid vendoring vcruntime140_threads.dll when building with Visual Studio 2022 version 17.8.

  • gh-113632: Promote WASI to a tier 2 platform and drop Emscripten from tier 3 in configure.ac.

  • gh-114099: configure and Makefile were refactored to accommodate framework builds on Apple platforms other than macOS.

  • gh-114875: Add getgrent() as a prerequisite for building the grp module.

Windows

  • gh-115049: Fixes py.exe launcher failing when run as users without user profiles.

  • gh-115009: Update Windows installer to use SQLite 3.45.1.

  • gh-109991: Update Windows build to use OpenSSL 3.0.13.

  • gh-111239: Update Windows builds to use zlib v1.3.1.

  • gh-100107: The py.exe launcher will no longer attempt to run the Microsoft Store redirector when launching a script containing a /usr/bin/env shebang

  • gh-112984: Adds free-threaded binaries to Windows installer as an optional component.

  • gh-89240: Allows multiprocessing to create pools of greater than 62 processes.

macOS

  • gh-115009: Update macOS installer to use SQLite 3.45.1.

  • gh-109991: Update macOS installer to use OpenSSL 3.0.13.

  • gh-114490: Add Mach-O linkage support for platform.architecture().

  • gh-87804: On macOS the result of os.statvfs and os.fstatvfs now correctly report the size of very large disks, in previous versions the reported number of blocks was wrong for disks with at least 2**32 blocks.

IDLE

  • gh-96905: In idlelib code, stop redefining built-ins 'dict' and 'object'.

  • gh-103820: Revise IDLE bindings so that events from mouse button 4/5 on non-X11 windowing systems (i.e. Win32 and Aqua) are not mistaken for scrolling.

Tools/Demos

  • gh-113516: Don't set LDSHARED when building for WASI.

  • gh-109991: Update GitHub CI workflows to use OpenSSL 3.0.13 and multissltests to use 1.1.1w, 3.0.13, 3.1.5, and 3.2.1.

  • gh-115015: Fix a bug in Argument Clinic that generated incorrect code for methods with no parameters that use the METH_METHOD | METH_FASTCALL | METH_KEYWORDS calling convention. Only the positional parameter count was checked; any keyword argument passed would be silently accepted.

C API

哋它亢 3.13.0 alpha 3

Release date: 2024-01-17

Security

  • gh-113659: Skip .pth files with names starting with a dot or hidden file attribute.

  • gh-112302: Created a Software Bill-of-Materials document and tooling for tracking dependencies.

Core and Builtins

  • gh-107901: Compiler duplicates basic blocks that have an eval breaker check, no line number, and multiple predecessors.

  • gh-107901: A jump leaving an exception handler back to normal code no longer checks the eval breaker.

  • gh-113655: Set the C recursion limit to 4000 on Windows, and 10000 on Linux/OSX. This seems to be near the sweet spot to maintain safety, but not compromise backwards compatibility.

  • gh-113710: Add typed stack effects to the interpreter DSL, along with various instruction annotations.

  • gh-77046: On Windows, file descriptors wrapping Windows handles are now created non inheritable by default (PEP 446). Patch by Zackery Spytz and Victor Stinner.

  • gh-113853: Guarantee that all executors make progress. This then guarantees that tier 2 execution always makes progress.

  • gh-113753: Fix an issue where the finalizer of PyAsyncGenASend objects might not be called if they were allocated from a free list.

  • gh-107901: Compiler changed so that synthetic jumps which are not at loop end no longer check the eval breaker.

  • gh-113703: Fix a regression in the codeop module that was causing it to incorrectly identify incomplete f-strings. Patch by Pablo Galindo

  • gh-89811: Check for a valid tp_version_tag before performing bytecode specializations that rely on this value being usable.

  • gh-111488: Changed error message in case of no 'in' keyword after 'for' in list comprehensions

  • gh-113657: Fix an issue that caused important instruction pointer updates to be optimized out of tier two traces.

  • gh-113603: Fixed bug where a redundant NOP is not removed, causing an assertion to fail in the compiler in debug mode.

  • gh-113602: Fix an error that was causing the parser to try to overwrite existing errors and crashing in the process. Patch by Pablo Galindo

  • gh-113486: No longer issue spurious PY_UNWIND events for optimized calls to classes.

  • gh-113297: Fix segfault in the compiler on with statement with 19 context managers.

  • gh-113212: Improve super error messages.

  • gh-111375: Only use NULL in the exception stack to indicate an exception was handled. Patch by Carey Metcalfe.

  • gh-112215: Increase the C recursion limit by a factor of 3 for non-debug builds, except for webassembly and s390 platforms which are unchanged. This mitigates some regressions in 3.12 with deep recursion mixing builtin (C) and 哋它亢 code.

  • gh-113054: Fixed bug where a redundant NOP is not removed, causing an assertion to fail in the compiler in debug mode.

  • gh-106905: Use per AST-parser state rather than global state to track recursion depth within the AST parser to prevent potential race condition due to simultaneous parsing.

    The issue primarily showed up in 3.11 by multithreaded users of ast.parse(). In 3.12 a change to when garbage collection can be triggered prevented the race condition from occurring.

  • gh-108866: Change the API and contract of _PyExecutorObject to return the next_instr pointer, instead of the frame, and to always execute at least one instruction.

  • gh-90350: Optimize builtin functions min() and max().

  • gh-112943: Correctly compute end column offsets for multiline tokens in the tokenize module. Patch by Pablo Galindo

  • gh-112125: Fix None.__ne__(None) returning NotImplemented instead of False.

  • gh-74616: input() now raises a ValueError when output on the terminal if the prompt contains embedded null characters instead of silently truncating it.

  • gh-112716: Fix SystemError in the import statement and in __reduce__() methods of builtin types when __builtins__ is not a dict.

  • gh-112730: Use color to highlight error locations in tracebacks. Patch by Pablo Galindo

  • gh-112625: Fixes a bug where a bytearray object could be cleared while iterating over an argument in the bytearray.join() method that could result in reading memory after it was freed.

  • gh-112660: Do not clear unexpected errors during formatting error messages for ImportError and AttributeError for modules.

  • gh-105967: Workaround a bug in Apple's macOS platform zlib library where zlib.crc32() and binascii.crc32() could produce incorrect results on multi-gigabyte inputs. Including when using zipfile on zips containing large data.

  • gh-95754: Provide a better error message when accessing invalid attributes on partially initialized modules. The origin of the module being accessed is now included in the message to help with the common issue of shadowing other modules.

  • gh-112217: Add check for the type of __cause__ returned from calling the type T in raise from T.

  • gh-111058: Change coro.cr_frame/gen.gi_frame to return None after the coroutine/generator has been closed. This fixes a bug where getcoroutinestate() and getgeneratorstate() return the wrong state for a closed coroutine/generator.

  • gh-112388: Fix an error that was causing the parser to try to overwrite tokenizer errors. Patch by pablo Galindo

  • gh-112387: Fix error positions for decoded strings with backwards tokenize errors. Patch by Pablo Galindo

  • gh-99606: Make code generated for an empty f-string identical to the code of an empty normal string.

  • gh-112367: Avoid undefined behaviour when using the perf trampolines by not freeing the code arenas until shutdown. Patch by Pablo Galindo

  • gh-112320: The Tier 2 translator now tracks the confidence level for staying "on trace" (i.e. not exiting back to the Tier 1 interpreter) for branch instructions based on the number of bits set in the branch "counter". Trace translation ends when the confidence drops below 1/3rd.

  • gh-109598: PyComplex_RealAsDouble()/PyComplex_ImagAsDouble() now tries to convert an object to a complex instance using its __complex__() method before falling back to the __float__() method. Patch by Sergey B Kirpichev.

  • gh-94606: Fix UnicodeEncodeError when email.message.get_payload() reads a message with a Unicode surrogate character and the message content is not well-formed for surrogateescape encoding. Patch by Sidney Markowitz.

  • bpo-21861: Use the object's actual class name in _io.FileIO.__repr__(), _io._WindowsConsoleIO() and _io.TextIOWrapper.__repr__(), to make these methods subclass friendly.

  • bpo-45369: Remove LibreSSL workarounds as per PEP 644.

  • bpo-34392: Added sys._is_interned().

Library

  • gh-114077: Fix possible OverflowError in socket.socket.sendfile() when pass count larger than 2 GiB on 32-bit platform.

  • gh-111803: plistlib now supports loading more deeply nested lists in binary format.

  • gh-114014: Fixed a bug in fractions.Fraction where an invalid string using d in the decimals part creates a different error compared to other invalid letters/characters. Patch by Jeremiah Gabriel Pascual.

  • gh-108364: sqlite3.Connection.iterdump() now ensures that foreign key support is disabled before dumping the database schema, if there is any foreign key violation. Patch by Erlend E. Aasland and Mariusz Felisiak.

  • gh-113971: The zipfile.ZipInfo previously protected ._compresslevel attribute has been made public as .compress_level with the old _compresslevel name remaining available as a property to retain compatibility.

  • gh-113877: Fix tkinter method winfo_pathname() on 64-bit Windows.

  • gh-113868: Added mmap.MAP_NORESERVE, mmap.MAP_NOEXTEND, mmap.MAP_HASSEMAPHORE, mmap.MAP_NOCACHE, mmap.MAP_JIT, mmap.MAP_RESILIENT_CODESIGN, mmap.MAP_RESILIENT_MEDIA, mmap.MAP_32BIT, mmap.MAP_TRANSLATED_ALLOW_EXECUTE, mmap.MAP_UNIX03 and mmap.MAP_TPRO. All of them are mmap(2) flags on macOS.

  • gh-113848: asyncio.TaskGroup() and asyncio.timeout() context managers now handle CancelledError subclasses as well as exact CancelledError.

  • gh-113661: unittest runner: Don't exit 5 if tests were skipped. The intention of exiting 5 was to detect issues where the test suite wasn't discovered at all. If we skipped tests, it was correctly discovered.

  • gh-96037: Insert TimeoutError in the context of the exception that was raised during exiting an expired asyncio.timeout() block.

  • gh-113781: Silence unraisable AttributeError when warnings are emitted during 哋它亢 finalization.

  • gh-113238: Add Anchor to importlib.resources (in order for the code to comply with the documentation)

  • gh-111693: asyncio.Condition.wait() now re-raises the same CancelledError instance that may have caused it to be interrupted. Fixed race condition in asyncio.Semaphore.acquire() when interrupted with a CancelledError.

  • gh-113791: Add CLOCK_MONOTONIC_RAW_APPROX and CLOCK_UPTIME_RAW_APPROX to time on macOS. These are clocks available on macOS 10.12 or later.

  • gh-112932: Restore the ability for zipfile to extractall from zip files with a "/" directory entry in them as is commonly added to zips by some wiki or bug tracker data exporters.

  • gh-113568: Raise deprecation warnings from pathlib.PurePath and not its private base class PurePathBase.

  • gh-113594: Fix UnicodeEncodeError in email when re-fold lines that contain unknown-8bit encoded part followed by non-unknown-8bit encoded part.

  • gh-113538: In asyncio.StreamReaderProtocol.connection_made(), there is callback that logs an error if the task wrapping the "connected callback" fails. This callback would itself fail if the task was cancelled. Prevent this by checking whether the task was cancelled first. If so, close the transport but don't log an error.

  • gh-113626: Add support for the allow_code argument in the marshal module. Passing allow_code=False prevents serialization and de-serialization of code objects which is incompatible between 哋它亢 versions.

  • gh-85567: Fix resource warnings for unclosed files in pickle and pickletools command line interfaces.

  • gh-113537: Support loads str in plistlib.loads().

  • gh-89850: Add default implementations of pickle.Pickler.persistent_id() and pickle.Unpickler.persistent_load() methods in the C implementation. Calling super().persistent_id() and super().persistent_load() in subclasses of the C implementation of pickle.Pickler and pickle.Unpickler classes no longer causes infinite recursion.

  • gh-113569: Indicate if there were no actual calls in unittest assert_has_calls() failure.

  • gh-101225: Increase the backlog for multiprocessing.connection.Listener objects created by multiprocessing.manager and multiprocessing.resource_sharer to significantly reduce the risk of getting a connection refused error when creating a multiprocessing.connection.Connection to them.

  • gh-113568: Raise audit events from pathlib.Path and not its private base class PathBase.

  • gh-113543: Make sure that webbrowser.MacOSXOSAScript sends webbrowser.open audit event.

  • gh-113028: When a second reference to a string appears in the input to pickle, and the 哋它亢 implementation is in use, we are guaranteed that a single copy gets pickled and a single object is shared when reloaded. Previously, in protocol 0, when a string contained certain characters (e.g. newline) it resulted in duplicate objects.

  • gh-113421: Fix multiprocessing logger for %(filename)s.

  • gh-111784: Fix segfaults in the _elementtree module. Fix first segfault during deallocation of _elementtree.XMLParser instances by keeping strong reference to pyexpat module in module state for capsule lifetime. Fix second segfault which happens in the same deallocation process by keeping strong reference to _elementtree module in XMLParser structure for _elementtree module lifetime.

  • gh-113407: Fix import of unittest.mock when C哋它亢 is built without docstrings.

  • gh-113320: Fix regression in 哋它亢 3.12 where Protocol classes that were not marked as runtime-checkable would be unnecessarily introspected, potentially causing exceptions to be raised if the protocol had problematic members. Patch by Alex Waygood.

  • gh-53502: Add a new option aware_datetime in plistlib to loads or dumps aware datetime.

  • gh-113358: Fix rendering tracebacks with exceptions with a broken __getattr__

  • gh-113214: Fix an AttributeError during asyncio SSL protocol aborts in SSL-over-SSL scenarios.

  • gh-113246: Update bundled pip to 23.3.2.

  • gh-87264: Fixed tarfile list() method to show file type.

  • gh-112182: asyncio.futures.Future.set_exception() now transforms StopIteration into RuntimeError instead of hanging or other misbehavior. Patch contributed by Jamie Phan.

  • gh-113225: Speed up pathlib.Path.glob() by using os.DirEntry.path where possible.

  • gh-113149: Improve error message when a JSON array or object contains a trailing comma. Patch by Carson Radtke.

  • gh-113117: The subprocess module can now use the os.posix_spawn() function with close_fds=True on platforms where posix_spawn_file_actions_addclosefrom_np is available. Patch by Jakub Kulik.

  • gh-113199: Make http.client.HTTPResponse.read1 and http.client.HTTPResponse.readline close IO after reading all data when content length is known. Patch by Illia Volochii.

  • gh-113191: Add support of os.fchmod() and a file descriptor in os.chmod() on Windows.

  • gh-113188: Fix shutil.copymode() and shutil.copystat() on Windows. Previously they worked differently if dst is a symbolic link: they modified the permission bits of dst itself rather than the file it points to if follow_symlinks is true or src is not a symbolic link, and did not modify the permission bits if follow_symlinks is false and src is a symbolic link.

  • gh-113119: os.posix_spawn() now accepts env=None, which makes the newly spawned process use the current process environment. Patch by Jakub Kulik.

  • gh-113202: Add a strict option to batched() in the itertools module.

  • gh-61648: Detect line numbers of properties in doctests.

  • gh-113175: Sync with importlib_metadata 7.0, including improved type annotations, fixed issue with symlinked packages in package_distributions, added EntryPoints.__repr__, introduced the diagnose script, added Distribution.origin property, and removed deprecated EntryPoint access by numeric index (tuple behavior).

  • gh-59616: Add support of os.lchmod() and the follow_symlinks argument in os.chmod() on Windows. Note that the default value of follow_symlinks in os.lchmod() is False on Windows.

  • gh-112559: signal.signal() and signal.getsignal() no longer call repr on callable handlers. asyncio.run() and asyncio.Runner.run() no longer call repr on the task results. Patch by Yilei Yang.

  • gh-112962: dis module functions add cache information to the Instruction instance rather than creating fake Instruction instances to represent the cache entries.

  • gh-112989: Reduce overhead to connect sockets with asyncio SelectorEventLoop.

  • gh-112970: Use closefrom() on Linux where available (e.g. glibc-2.34), rather than only FreeBSD.

  • gh-110190: Fix ctypes structs with array on PPC64LE platform by setting MAX_STRUCT_SIZE to 64 in stgdict. Patch by Diego Russo.

  • gh-112540: The statistics.geometric_mean() function now returns zero for datasets containing a zero. Formerly, it would raise an exception.

  • gh-87286: Added LOG_FTP, LOG_NETINFO, LOG_REMOTEAUTH, LOG_INSTALL, LOG_RAS, and LOG_LAUNCHD tot the syslog module, all of them constants on used on macOS.

  • gh-112800: Fix asyncio SubprocessTransport.close() not to throw PermissionError when used with setuid executables.

  • gh-51944: Add the following constants to the termios module. These values are present in macOS system headers: ALTWERASE, B14400, B28800, B7200, B76800, CCAR_OFLOW, CCTS_OFLOW, CDSR_OFLOW, CDTR_IFLOW, CIGNORE, CRTS_IFLOW, EXTPROC, IUTF8, MDMBUF, NL2, NL3, NOKERNINFO, ONOEOT, OXTABS, VDSUSP, VSTATUS.

  • gh-79325: Fix an infinite recursion error in tempfile.TemporaryDirectory() cleanup on Windows.

  • gh-94692: shutil.rmtree() now only catches OSError exceptions. Previously a symlink attack resistant version of shutil.rmtree() could ignore or pass to the error handler arbitrary exception when invalid arguments were provided.

  • gh-112736: The use of del-safe symbols in subprocess was refactored to allow for use in cross-platform build environments.

  • gh-112727: Speed up pathlib.Path.absolute(). Patch by Barney Gale.

  • gh-74690: Speedup issubclass() checks against simple runtime-checkable protocols by around 6%. Patch by Alex Waygood.

  • gh-74690: Speedup isinstance() checks by roughly 20% for runtime-checkable protocols that only have one callable member. Speedup issubclass() checks for these protocols by roughly 10%. Patch by Alex Waygood.

  • gh-112645: Remove deprecation error on passing onerror to shutil.rmtree().

  • gh-112640: Add kwdefaults parameter to types.FunctionType to set default keyword argument values.

  • gh-112622: Ensure name parameter is passed to event loop in asyncio.create_task().

  • gh-112618: Fix a caching bug relating to typing.Annotated. Annotated[str, True] is no longer identical to Annotated[str, 1].

  • gh-112334: Fixed a performance regression in 3.12's subprocess on Linux where it would no longer use the fast-path vfork() system call when it could have due to a logic bug, instead falling back to the safe but slower fork().

    Also fixed a second 3.12.0 potential security bug. If a value of extra_groups=[] was passed to subprocess.Popen or related APIs, the underlying setgroups(0, NULL) system call to clear the groups list would not be made in the child process prior to exec().

    This was identified via code inspection in the process of fixing the first bug.

  • gh-110190: Fix ctypes structs with array on Arm platform by setting MAX_STRUCT_SIZE to 32 in stgdict. Patch by Diego Russo.

  • gh-81194: Fix a crash in socket.if_indextoname() with specific value (UINT_MAX). Fix an integer overflow in socket.if_indextoname() on 64-bit non-Windows platforms.

  • gh-112578: Fix a spurious RuntimeWarning when executing the zipfile module.

  • gh-112516: Update the bundled copy of pip to version 23.3.1.

  • gh-112510: Add readline.backend for the backend readline uses (editline or readline)

  • gh-112328: [Enum] Make EnumDict, EnumDict.member_names, EnumType._add_alias_ and EnumType._add_value_alias_ public.

  • gh-112509: Fix edge cases that could cause a key to be present in both the __required_keys__ and __optional_keys__ attributes of a typing.TypedDict. Patch by Jelle Zijlstra.

  • gh-101336: Add keep_alive keyword parameter for AbstractEventLoop.create_server() and BaseEventLoop.create_server().

  • gh-63284: Added support for TLS-PSK (pre-shared key) mode to the ssl module.

  • gh-112414: Fix regression in 哋它亢 3.12 where calling repr() on a module that had been imported using a custom loader could fail with AttributeError. Patch by Alex Waygood.

  • gh-112358: Revert change to struct.Struct initialization that broke some cases of subclassing.

  • gh-112405: Optimize pathlib.PurePath.relative_to(). Patch by Alex Waygood.

  • gh-94722: Fix bug where comparison between instances of DocTest fails if one of them has None as its lineno.

  • gh-112361: Speed up a small handful of pathlib methods by removing some temporary objects.

  • gh-112345: Improve error message when trying to call issubclass() against a typing.Protocol that has non-method members. Patch by Randolf Scholz.

  • gh-112137: Change dis output to display no-lineno as "--" instead of "None".

  • gh-112332: Deprecate the exc_type field of traceback.TracebackException. Add exc_type_str to replace it.

  • gh-81620: Add extra tests for random.binomialvariate()

  • gh-112292: Fix a crash in readline when imported from a sub interpreter. Patch by Anthony Shaw

  • gh-77621: Slightly improve the import time of the pathlib module by deferring some imports. Patch by Barney Gale.

  • gh-112137: Change dis output to display logical labels for jump targets instead of offsets.

  • gh-112139: Add Signature.format() to format signatures to string with extra options. And use it in pydoc to render more readable signatures that have new lines between parameters.

  • gh-112105: Make readline.set_completer_delims() work with libedit

  • gh-106922: Display multiple lines with traceback when errors span multiple lines.

  • gh-111874: When creating a typing.NamedTuple class, ensure __set_name__() is called on all objects that define __set_name__ and exist in the values of the NamedTuple class's class dictionary. Patch by Alex Waygood.

  • gh-68166: Add support of the "vsapi" element type in tkinter.ttk.Style.element_create().

  • gh-110275: Named tuple's methods _replace() and __replace__() now raise TypeError instead of ValueError for invalid keyword arguments.

  • gh-99367: Do not mangle sys.path[0] in pdb if safe_path is set

  • gh-111615: Fix a regression caused by a fix to gh-93162 whereby you couldn't configure a QueueHandler without specifying handlers.

  • gh-75666: Fix the behavior of tkinter widget's unbind() method with two arguments. Previously, widget.unbind(sequence, funcid) destroyed the current binding for sequence, leaving sequence unbound, and deleted the funcid command. Now it removes only funcid from the binding for sequence, keeping other commands, and deletes the funcid command. It leaves sequence unbound only if funcid was the last bound command.

  • gh-67790: Implement basic formatting support (minimum width, alignment, fill) for fractions.Fraction.

  • gh-111049: Fix crash during garbage collection of the io.BytesIO buffer object.

  • gh-102980: Redirect the output of interact command of pdb to the same channel as the debugger. Add tests and improve docs.

  • gh-102988: email.utils.getaddresses() and email.utils.parseaddr() now return ('', '') 2-tuples in more situations where invalid email addresses are encountered instead of potentially inaccurate values. Add optional strict parameter to these two functions: use strict=False to get the old behavior, accept malformed inputs. getattr(email.utils, 'supports_strict_parsing', False) can be use to check if the strict parameter is available. Patch by Thomas Dwyer and Victor Stinner to improve the CVE 2023-27043 fix.

  • gh-52161: cmd.Cmd.do_help() now cleans docstrings with inspect.cleandoc() before writing them. Patch by Filip Łapkiewicz.

  • gh-82300: Add track parameter to multiprocessing.shared_memory.SharedMemory that allows using shared memory blocks without having to register with the POSIX resource tracker that automatically releases them upon process exit.

  • gh-110109: Add private pathlib._PurePathBase class: a base class for pathlib.PurePath that omits certain magic methods. It may be made public (along with _PathBase) in future.

  • gh-109858: Protect zipfile from "quoted-overlap" zipbomb. It now raises BadZipFile when try to read an entry that overlaps with other entry or central directory.

  • gh-109786: Fix possible reference leaks and crash when re-enter the __next__() method of itertools.pairwise.

  • gh-91539: Small (10 - 20%) and trivial performance improvement of urllib.request.getproxies_environment(), typically useful when there are many environment variables to go over.

  • gh-103363: Add follow_symlinks keyword-only argument to pathlib.Path.owner() and group(), defaulting to True.

  • gh-102130: Support tab completion in cmd for editline.

  • gh-99437: runpy.run_path() now decodes path-like objects, making sure __file__ and sys.argv[0] of the module being run are always strings.

  • gh-104003: Add warnings.deprecated(), a decorator to mark deprecated functions to static type checkers and to warn on usage of deprecated classes and functions. See PEP 702. Patch by Jelle Zijlstra.

  • gh-103708: Make hardcoded 哋它亢 name, a configurable parameter so that different implementations of 哋它亢 can override it instead of making huge diffs in sysconfig.py

  • gh-66515: mailbox.MH now supports folders that do not contain a .mh_sequences file (e.g. Claws Mail IMAP-cache folders). Patch by Serhiy Storchaka.

  • gh-83162: Renamed re.error to PatternError for clarity, and kept re.error for backward compatibility. Patch by Matthias Bussonnier and Adam Chhina.

  • gh-91133: Fix a bug in tempfile.TemporaryDirectory cleanup, which now no longer dereferences symlinks when working around file system permission errors.

  • bpo-43153: On Windows, tempfile.TemporaryDirectory previously masked a PermissionError with NotADirectoryError during directory cleanup. It now correctly raises PermissionError if errors are not ignored. Patch by Andrei Kulakov and Ken Jin.

  • bpo-32731: getpass.getuser() now raises OSError for all failures rather than ImportError on systems lacking the pwd module or KeyError if the password database is empty.

  • bpo-34321: mmap.mmap now has a trackfd parameter on Unix; if it is False, the file descriptor specified by fileno will not be duplicated.

  • bpo-35332: The shutil.rmtree() function now ignores errors when calling os.close() when ignore_errors is True, and os.close() no longer retried after error.

  • bpo-35928: io.TextIOWrapper now correctly handles the decoding buffer after read() and write().

  • bpo-26791: shutil.move() now moves a symlink into a directory when that directory is the target of the symlink. This provides the same behavior as the mv shell command. The previous behavior raised an exception. Patch by Jeffrey Kintscher.

  • bpo-41422: Fixed memory leaks of pickle.Pickler and pickle.Unpickler involving cyclic references via the internal memo mapping.

  • bpo-19821: The pydoc.ispackage() function has been deprecated.

  • bpo-40262: The ssl.SSLSocket.recv_into() method no longer requires the buffer argument to implement __len__ and supports buffers with arbitrary item size.

  • bpo-39912: warnings.filterwarnings() and warnings.simplefilter() now raise appropriate exceptions instead of AssertionError. Patch contributed by Rémi Lapeyre.

  • bpo-37260: Fixed a race condition in shutil.rmtree() in which directory entries removed by another process or thread while shutil.rmtree() is running can cause it to raise FileNotFoundError. Patch by Jeffrey Kintscher.

  • bpo-36959: Fix some error messages for invalid ISO format string combinations in strptime() that referred to directives not contained in the format string. Patch by Gordon P. Hemsley.

  • bpo-18060: Fixed a class inheritance issue that can cause segfaults when deriving two or more levels of subclasses from a base class of Structure or Union.

  • bpo-29779: Add a new 哋它亢_HISTORY environment variable to set the location of a .哋它亢_history file.

  • bpo-21360: mailbox.Maildir now ignores files with a leading dot.

Documentation

  • gh-111699: Relocate smtpd deprecation notice to its own section rather than under locale in What's New in 哋它亢 3.12 document

  • gh-110746: Improved markup for valid options/values for methods ttk.treeview.column and ttk.treeview.heading, and for Layouts.

  • gh-95649: Document that the asyncio module contains code taken from v0.16.0 of the uvloop project, as well as the required MIT licensing information.

Tests

  • gh-111798: Disable test_super_deep() from test_call under pydebug builds on WASI; the stack depth is too small to make the test useful.

  • gh-111801: Lower the recursion limit in test_isinstance for test_infinitely_many_bases(). This prevents a stack overflow on a pydebug build of WASI.

  • gh-111802: Specify a low recursion depth for test_bad_getattr() in test.pickletester to avoid exhausting the stack under a pydebug build for WASI.

  • gh-44626: Fix os.path.isabs() incorrectly returning True when given a path that starts with exactly one (back)slash on Windows.

    Fix pathlib.PureWindowsPath.is_absolute() incorrectly returning False for some paths beginning with two (back)slashes.

  • gh-113633: Use module state for the _testcapi extension module.

  • gh-109980: Fix test_tarfile_vs_tar in test_shutil for macOS, where system tar can include more information in the archive than shutil.make_archive.

  • gh-112769: The tests now correctly compare zlib version when zlib.ZLIB_RUNTIME_VERSION contains non-integer suffixes. For example zlib-ng defines the version as 1.3.0.zlib-ng.

  • gh-112334: Adds a regression test to verify that vfork() is used when expected by subprocess on vfork enabled POSIX systems (Linux).

  • gh-108927: Fixed order dependence in running tests in the same process when a test that has submodules (e.g. test_importlib) follows a test that imports its submodule (e.g. test_importlib.util) and precedes a test (e.g. test_unittest or test_compileall) that uses that submodule.

  • bpo-40648: Test modes that file can get with chmod() on Windows.

Build

  • gh-114013: Fix Tools/wasm/wasi.py to not include the path to 哋它亢.wasm as part of HOSTRUNNER. The environment variable is meant to specify how to run the WASI host only, having 哋它亢.wasm and relevant flags appended to the HOSTRUNNER. This fixes make test work.

  • gh-113258: Changed the Windows build to write out generated frozen modules into the build tree instead of the source tree.

  • gh-112305: Fixed the check-clean-src step performed on out of tree builds to detect errant $(srcdir)/哋它亢/frozen_modules/*.h files and recommend appropriate source tree cleanup steps to get a working build again.

  • gh-112536: Add support for thread sanitizer (TSAN)

  • gh-112867: Fix the build for the case that WITH_PYMALLOC_RADIX_TREE=0 set.

  • gh-103065: Introduce Tools/wasm/wasi.py to simplify doing a WASI build.

  • bpo-11102: The os.major(), os.makedev(), and os.minor() functions are now available on HP-UX v3.

  • bpo-36351: Do not set ipv6type when cross-compiling.

Windows

  • gh-114096: Process privileges that are activated for creating directory junctions are now restored afterwards, avoiding behaviour changes in other parts of the program.

  • gh-111877: os.stat() calls were returning incorrect time values for files that could not be accessed directly.

  • gh-111973: Update Windows installer to use SQLite 3.44.2.

  • gh-113009: multiprocessing: On Windows, fix a race condition in Process.terminate(): no longer set the returncode attribute to always call WaitForSingleObject() in Process.wait(). Previously, sometimes the process was still running after TerminateProcess() even if GetExitCodeProcess() is not STILL_ACTIVE. Patch by Victor Stinner.

  • gh-86179: Fixes path calculations when launching 哋它亢 on Windows through a symlink.

  • gh-71383: Update Tcl/Tk in Windows installer to 8.6.13 with a patch to suppress incorrect ThemeChanged warnings.

  • gh-111650: Ensures the Py_GIL_DISABLED preprocessor variable is defined in pyconfig.h so that extension modules written in C are able to use it.

  • gh-112278: Reduce the time cost for some functions in platform on Windows if current user has no permission to the WMI.

  • gh-73427: Deprecate sys._enablelegacywindowsfsencoding(). Use 哋它亢LEGACYWINDOWSFSENCODING instead. Patch by Inada Naoki.

  • gh-87868: Correctly sort and remove duplicate environment variables in _winapi.CreateProcess().

  • bpo-37308: Fix mojibake in mmap.mmap when using a non-ASCII tagname argument on Windows.

macOS

  • gh-113666: Add the following constants to module stat: UF_SETTABLE, UF_TRACKED, UF_DATAVAULT, SF_SUPPORTED, SF_SETTABLE, SF_SYNTHETIC, SF_RESTRICTED, SF_FIRMLINK and SF_DATALESS. The values UF_SETTABLE, SF_SUPPORTED, SF_SETTABLE and SF_SYNTHETIC are only available on macOS.

  • gh-113536: os.waitid() is now available on macOS

  • gh-110459: Running configure ... --with-openssl-rpath=X/Y/Z no longer fails to detect OpenSSL on macOS.

  • gh-74573: Document that dbm.ndbm can silently corrupt DBM files on updates when exceeding undocumented platform limits, and can crash (segmentation fault) when reading such a corrupted file. (FB8919203)

  • gh-65701: The freeze tool doesn't work with framework builds of 哋它亢. Document this and bail out early when running the tool with such a build.

  • gh-87277: webbrowser: Don't look for X11 browsers on macOS. Those are generally not used and probing for them can result in starting XQuartz even if it isn't used otherwise.

  • gh-111973: Update macOS installer to use SQLite 3.44.2.

  • gh-108269: Set CFBundleAllowMixedLocalizations to true in the Info.plist for the framework, embedded 哋它亢.app and IDLE.app with framework installs on macOS. This allows applications to pick up the user's preferred locale when that's different from english.

  • gh-102362: Make sure the result of sysconfig.get_plaform() includes at least a major and minor versions, even if MACOSX_DEPLOYMENT_TARGET is set to only a major version during build to match the format expected by pip.

  • gh-110017: Disable a signal handling stress test on macOS due to a bug in macOS (FB13453490).

  • gh-110820: Make sure the preprocessor definitions for ALIGNOF_MAX_ALIGN_T, SIZEOF_LONG_DOUBLE and HAVE_GCC_ASM_FOR_X64 are correct for Universal 2 builds on macOS.

  • gh-109981: Use /dev/fd on macOS to determine the number of open files in test.support.os_helper.fd_count to avoid a crash with "guarded" file descriptors when probing for open files.

IDLE

  • gh-72284: Improve the lists of features, editor key bindings, and shell key bingings in the IDLE doc.

  • gh-113903: Fix rare failure of test.test_idle, in test_configdialog.

  • gh-113729: Fix the "Help -> IDLE Doc" menu bug in 3.11.7 and 3.12.1.

  • gh-113269: Fix test_editor hang on macOS Catalina.

  • gh-112898: Fix processing unsaved files when quitting IDLE on macOS.

  • bpo-13586: Enter the selected text when opening the "Replace" dialog.

C API

哋它亢 3.13.0 alpha 2

Release date: 2023-11-22

Core and Builtins

  • gh-112243: Don't include comments in f-string debug expressions. Patch by Pablo Galindo

  • gh-112287: Slightly optimize the Tier 2 (uop) interpreter by only loading oparg and operand when needed. Also double the trace size limit again, to 512 this time.

  • gh-112266: Change docstrings of __dict__ and __weakref__.

  • gh-111807: Lower the max parser stack depth to 1000 under WASI debug builds.

  • gh-111798: When 哋它亢 is built in debug mode, set the C recursion limit to 500 instead of 1500. A debug build is likely built with low optimization level which implies higher stack memory usage than a release build. Patch by Victor Stinner.

  • gh-106529: Enable translating unspecialized FOR_ITER to Tier 2.

  • gh-111916: Make hashlib related modules thread-safe without the GIL

  • gh-81137: Deprecate assignment to a function's __code__ field when the new code object is of a mismatched type (e.g., from a generator to a plain function).

  • gh-79932: Raise exception if frame.clear() is called on a suspended frame.

  • gh-81925: Implement native thread ids for GNU KFreeBSD.

  • gh-111843: Use exponential backoff to reduce the number of failed tier 2 optimization attempts by over 99%.

  • gh-110829: Joining a thread now ensures the underlying OS thread has exited. This is required for safer fork() in multi-threaded processes.

  • gh-109369: Make sure that tier 2 traces are de-optimized if the code is instrumented

  • gh-111772: Specialize slot loads and stores for _Py_T_OBJECT as well as Py_T_OBJECT_EX

  • gh-111666: Speed up BaseExceptionGroup.derive(), BaseExceptionGroup.subgroup(), and BaseExceptionGroup.split() by changing how they parse passed arguments.

  • gh-111654: Fix runtime crash when some error happens in opcode LOAD_FROM_DICT_OR_DEREF.

  • gh-111623: Add support for sharing tuples between interpreters using the cross-interpreter API. Patch by Anthony Shaw.

  • gh-111354: The oparg of YIELD_VALUE is now 1 if the instruction is part of a yield-from or await, and 0 otherwise.

    The SUSPENDED frame state is now split into SUSPENDED and SUSPENDED_YIELD_FROM. This simplifies the code in _PyGen_yf.

  • gh-111520: Merge the Tier 1 (bytecode) and Tier 2 (micro-ops) interpreters together, moving the Tier 2 interpreter loop and switch into _PyEval_EvalFrameDefault() in 哋它亢/ceval.c. The 哋它亢/executor.c file is gone. Also the TIER_ONE and TIER_TWO macros are now handled by the code generator.

    Beware! This changes the environment variables to enable micro-ops and their debugging to 哋它亢_UOPS and 哋它亢_LLTRACE.

  • gh-109181: Speed up Traceback object creation by lazily compute the line number. Patch by Pablo Galindo

  • gh-111420: Allow type comments in parenthesized with statements

  • gh-111438: Add support for sharing floats between interpreters using the cross-interpreter API. Patch by Anthony Shaw.

  • gh-111435: Add support for sharing of True and False between interpreters using the cross-interpreter API. Patch by Anthony Shaw.

  • gh-102388: Fix a bug where iso2022_jp_3 and iso2022_jp_2004 codecs read out of bounds

  • gh-111366: Fix an issue in the codeop that was causing SyntaxError exceptions raised in the presence of invalid syntax to not contain precise error messages. Patch by Pablo Galindo

  • gh-111380: Fix a bug that was causing SyntaxWarning to appear twice when parsing if invalid syntax is encountered later. Patch by Pablo galindo

  • gh-111374: Added a new environment variable 哋它亢_FROZEN_MODULES. It determines whether or not frozen modules are ignored by the import machinery, equivalent of the -X frozen_modules command-line option.

  • gh-111354: Remove oparg from YIELD_VALUE. Change oparg of RESUME to include information about the except-depth. These changes make it possible to simplify the code in generator close.

  • gh-94438: Fix a regression that prevented jumping across is None and is not None when debugging. Patch by Savannah Ostrowski.

  • gh-67224: Show source lines in tracebacks when using the -c option when running 哋它亢. Patch by Pablo Galindo

  • gh-111123: Fix a bug where a global declaration in an except block is rejected when the global is used in the else block.

  • gh-110938: Fix error messages for indented blocks with functions and classes with generic type parameters. Patch by Pablo Galindo

  • gh-109214: Remove unnecessary instruction pointer updates before returning from frames.

  • gh-110912: Correctly display the traceback for MemoryError exceptions using the traceback module. Patch by Pablo Galindo

  • gh-109894: Fixed crash due to improperly initialized static MemoryError in subinterpreter.

  • gh-110892: Return NULL for PyTrace_RETURN events caused by an exception

  • gh-110864: Fix argument parsing by _PyArg_UnpackKeywordsWithVararg for functions defining pos-or-keyword, vararg, and kw-only parameters.

  • gh-109094: Replace prev_instr on the interpreter frame by instr_ptr which points to the beginning of the instruction that is currently executing (or will execute once the frame resumes).

  • gh-110805: Allow the repl to show source code and complete tracebacks. Patch by Pablo Galindo

  • gh-110722: Add 哋它亢_PRESITE=package.module to import a module early in the interpreter lifecycle before site.py is executed. 哋它亢 needs to be built in debug mode for this option to exist.

  • gh-110481: Implement biased reference counting in --disable-gil builds.

  • gh-110543: Fix regression in 哋它亢 3.12 where types.CodeType.replace() would produce a broken code object if called on a module or class code object that contains a comprehension. Patch by Jelle Zijlstra.

  • gh-89519: Removed chained classmethod descriptors (introduced in bpo-19072). This can no longer be used to wrap other descriptors such as property. The core design of this feature was flawed and caused a number of downstream problems. To "pass-through" a classmethod, consider using the __wrapped__ attribute that was added in 哋它亢 3.10.

  • gh-103615: Use local events for opcode tracing

  • bpo-46657: Add mimalloc memory allocator support.

  • gh-106718: When PyConfig.stdlib_dir is explicitly set, it's now respected and won't be overridden by PyConfig.home.

  • gh-106905: Fix incorrect SystemError about AST constructor recursion depth mismatch.

  • gh-100445: Improve error message for unterminated strings with escapes.

  • bpo-45759: Improved error messages for elif/else statements not matching any valid statements. Patch by Jeremiah Vivian.

Library

Tests

  • gh-111808: Make the default value of test.support.infinite_recursion() to be conditional based on whether optimizations were used when compiling the interpreter. This helps with platforms like WASI whose stack size is greatly restricted in debug builds.

  • gh-110722: Gathering line coverage of standard libraries within the regression test suite is now precise, as well as much faster. Patch by Łukasz Langa.

  • gh-110367: Make regrtest --verbose3 option compatible with --huntrleaks -jN options. The ./哋它亢 -m test -j1 -R 3:3 --verbose3 command now works as expected. Patch by Victor Stinner.

  • gh-111165: Remove no longer used functions run_unittest() and run_doctest() from the test.support module.

  • gh-110932: Fix regrtest if the SOURCE_DATE_EPOCH environment variable is defined: use the variable value as the random seed. Patch by Victor Stinner.

  • gh-110995: test_gdb: Fix detection of gdb built without 哋它亢 scripting support. Patch by Victor Stinner.

  • gh-110918: Test case matching patterns specified by options --match, --ignore, --matchfile and --ignorefile are now tested in the order of specification, and the last match determines whether the test case be run or ignored.

  • gh-108747: Add unit test for usercustomize and sitecustomize hooks from site.

Build

  • gh-96954: Make make regen-unicodedata work for out-of-tree builds of C哋它亢.

  • gh-112088: Add Tools/build/regen-configure.sh script to regenerate the configure with an Ubuntu container image. The quay.io/tiran/c哋它亢_autoconf:271 container image (tiran/c哋它亢_autoconf) is no longer used. Patch by Victor Stinner.

  • gh-111046: For wasi-threads, memory is now exported to fix compatibility issues with some wasm runtimes.

  • gh-110828: AIX 32bit needs -latomic to build the _testcapi extension module.

  • gh-85283: The errno, md5, resource, winsound, _ctypes_test, _multiprocessing.posixshmem, _scproxy, _stat, _testimportmultiple and _uuid C extensions are now built with the limited C API. Patch by Victor Stinner.

Windows

  • gh-111856: Fixes fstat() on file systems that do not support file ID requests. This includes FAT32 and exFAT.

  • gh-111293: Fix os.DirEntry.inode dropping higher 64 bits of a file id on some filesystems on Windows.

  • gh-110913: WindowsConsoleIO now correctly chunks large buffers without splitting up UTF-8 sequences.

macOS

  • gh-59703: For macOS framework builds, in getpath.c use the system dladdr function to find the path to the shared library rather than depending on deprecated macOS APIs.

  • gh-110950: Update macOS installer to include an upstream Tcl/Tk fix for the Secure coding is not enabled for restorable state! warning encountered in Tkinter on macOS 14 Sonoma.

  • gh-111015: Ensure that IDLE.app and 哋它亢 Launcher.app are installed with appropriate permissions on macOS builds.

  • gh-71383: Update macOS installer to include an upstream Tcl/Tk fix for the ttk::ThemeChanged error encountered in Tkinter.

  • gh-92603: Update macOS installer to include a fix accepted by upstream Tcl/Tk for a crash encountered after the first tkinter.Tk() instance is destroyed.

IDLE

  • bpo-35668: Add docstrings to the IDLE debugger module. Fix two bugs: initialize Idb.botframe (should be in Bdb); in Idb.in_rpc_code, check whether prev_frame is None before trying to use it. Greatly expand test_debugger.

Tools/Demos

  • gh-111903: Argument Clinic now supports the @critical_section directive that instructs Argument Clinic to generate a critical section around the function call, which locks the self object in --disable-gil builds. Patch by Sam Gross.

C API

  • gh-112026: Add again the private _PyThreadState_UncheckedGet() function as an alias to the new public PyThreadState_GetUnchecked() function. Patch by Victor Stinner.

  • gh-112026: Restore the removed _PyDict_GetItemStringWithError() function. It is used by numpy. Patch by Victor Stinner.

  • gh-112026: Restore removed private C API functions, macros and structures which have no simple replacement for now:

    • _PyDict_GetItem_KnownHash()

    • _PyDict_NewPresized()

    • _PyHASH_BITS

    • _PyHASH_IMAG

    • _PyHASH_INF

    • _PyHASH_MODULUS

    • _PyHASH_MULTIPLIER

    • _PyLong_Copy()

    • _PyLong_FromDigits()

    • _PyLong_New()

    • _PyLong_Sign()

    • _PyObject_CallMethodId()

    • _PyObject_CallMethodNoArgs()

    • _PyObject_CallMethodOneArg()

    • _PyObject_CallOneArg()

    • _PyObject_EXTRA_INIT

    • _PyObject_FastCallDict()

    • _PyObject_GetAttrId()

    • _PyObject_Vectorcall()

    • _PyObject_VectorcallMethod()

    • _PyStack_AsDict()

    • _PyThread_CurrentFrames()

    • _PyUnicodeWriter structure

    • _PyUnicodeWriter_Dealloc()

    • _PyUnicodeWriter_Finish()

    • _PyUnicodeWriter_Init()

    • _PyUnicodeWriter_Prepare()

    • _PyUnicodeWriter_PrepareKind()

    • _PyUnicodeWriter_WriteASCIIString()

    • _PyUnicodeWriter_WriteChar()

    • _PyUnicodeWriter_WriteLatin1String()

    • _PyUnicodeWriter_WriteStr()

    • _PyUnicodeWriter_WriteSubstring()

    • _PyUnicode_AsString()

    • _PyUnicode_FromId()

    • _PyVectorcall_Function()

    • _Py_IDENTIFIER()

    • _Py_c_abs()

    • _Py_c_diff()

    • _Py_c_neg()

    • _Py_c_pow()

    • _Py_c_prod()

    • _Py_c_quot()

    • _Py_c_sum()

    • _Py_static_string()

    • _Py_static_string_init()

    Patch by Victor Stinner.

  • gh-112026: Add again <ctype.h> and <unistd.h> includes in 哋它亢.h, but don't include them in the limited C API version 3.13 and newer. Patch by Victor Stinner.

  • gh-111956: Add internal-only one-time initialization API: _PyOnceFlag and _PyOnceFlag_CallOnce.

  • gh-111262: Add PyDict_Pop() and PyDict_PopString() functions: remove a key from a dictionary and optionally return the removed value. This is similar to dict.pop(), but without the default value and not raising KeyError if the key missing. Patch by Stefan Behnel and Victor Stinner.

  • gh-111863: Rename Py_NOGIL to Py_GIL_DISABLED. Patch by Hugo van Kemenade.

  • gh-111138: Add PyList_Extend() and PyList_Clear() functions: similar to 哋它亢 list.extend() and list.clear() methods. Patch by Victor Stinner.

  • gh-108765: On Windows, 哋它亢.h no longer includes the <stddef.h> standard header file. If needed, it should now be included explicitly. Patch by Victor Stinner.

  • gh-111569: Implement "哋它亢 Critical Sections" from PEP 703. These are macros to help replace the GIL with per-object locks in the --disable-gil build of C哋它亢. The macros are no-ops in the default build.

  • gh-111506: In the limited C API version 3.13, Py_SET_REFCNT() function is now implemented as an opaque function call. Patch by Victor Stinner.

  • gh-108082: Add PyErr_FormatUnraisable() function.

  • gh-110964: Move the undocumented private _PyArg functions and _PyArg_Parser structure to internal C API (pycore_modsupport.h). Patch by Victor Stinner.

  • gh-110815: Support non-ASCII keyword names in PyArg_ParseTupleAndKeywords().

  • gh-109587: Introduced PyUnstable_PerfTrampoline_CompileCode(), PyUnstable_PerfTrampoline_SetPersistAfterFork() and PyUnstable_CopyPerfMapFile(). These functions allow extension modules to initialize trampolines eagerly, after the application is "warmed up". This makes it possible to have perf-trampolines running in an always-enabled fashion.

  • gh-85283: Add the PySys_Audit() function to the limited C API. Patch by Victor Stinner.

  • gh-85283: Add PyMem_RawMalloc(), PyMem_RawCalloc(), PyMem_RawRealloc() and PyMem_RawFree() to the limited C API. Patch by Victor Stinner.

  • gh-106672: Functions PyDict_GetItem(), PyDict_GetItemString(), PyMapping_HasKey(), PyMapping_HasKeyString(), PyObject_HasAttr(), PyObject_HasAttrString(), and PySys_GetObject(), which clear all errors occurred during calling the function, report now them using sys.unraisablehook().

  • gh-67565: Remove redundant C-contiguity check in getargs.c, binascii, ssl and Argument Clinic. Patched by Stefan Krah and Furkan Onder

哋它亢 3.13.0 alpha 1

Release date: 2023-10-13

Security

  • gh-108310: Fixed an issue where instances of ssl.SSLSocket were vulnerable to a bypass of the TLS handshake and included protections (like certificate verification) and treating sent unencrypted data as if it were post-handshake TLS encrypted data. Security issue reported as CVE 2023-40217 by Aapo Oksman. Patch by Gregory P. Smith.

  • gh-107774: PEP 669 specifies that sys.monitoring.register_callback will generate an audit event. Pre-releases of 哋它亢 3.12 did not generate the audit event. This is now fixed.

  • gh-102988: Reverted the email.utils security improvement change released in 3.12beta4 that unintentionally caused email.utils.getaddresses to fail to parse email addresses with a comma in the quoted name field. See gh-106669.

  • gh-99108: Refresh our new HACL* built-in hashlib code from upstream. Built-in SHA2 should be faster and an issue with SHA3 on 32-bit platforms is fixed.

  • gh-102509: Start initializing ob_digit during creation of PyLongObject objects. Patch by Illia Volochii.

Core and Builtins

  • gh-110782: Fix crash when typing.TypeVar is constructed with a keyword argument. Patch by Jelle Zijlstra.

  • gh-110752: Reset ceval.eval_breaker in interpreter_clear()

  • gh-110721: Use the traceback implementation for the default PyErr_Display() functionality. Patch by Pablo Galindo

  • gh-110696: Fix incorrect error message for invalid argument unpacking. Patch by Pablo Galindo

  • gh-104169: Split the tokenizer into two separate directories: - One part includes the actual lexeme producing logic and lives in Parser/lexer. - The second part wraps the lexer according to the different tokenization modes we have (string, utf-8, file, interactive, readline) and lives in Parser/tokenizer.

  • gh-110688: Remove undocumented test_c_api method from set, which was only defined for testing purposes under Py_DEBUG. Now we have proper CAPI tests.

  • gh-104584: Fix a reference leak when running with 哋它亢UOPS or -X uops enabled.

  • gh-110514: Add PY_THROW to sys.setprofile() events

  • gh-110489: Optimise math.ceil() when the input is exactly a float, resulting in about a 10% improvement.

  • gh-110455: Guard assert(tstate->thread_id > 0) with #ifndef HAVE_PTHREAD_STUBS. This allows for for pydebug builds to work under WASI which (currently) lacks thread support.

  • gh-110309: Remove unnecessary empty constant nodes in the ast of f-string specs.

  • gh-110259: Correctly identify the format spec in f-strings (with single or triple quotes) that have multiple lines in the expression part and include a formatting spec. Patch by Pablo Galindo

  • gh-110237: Fix missing error checks for calls to PyList_Append in _PyEval_MatchClass.

  • gh-110164: regrtest: If the SOURCE_DATE_EPOCH environment variable is defined, regrtest now disables tests randomization. Patch by Victor Stinner.

  • gh-109889: Fix the compiler's redundant NOP detection algorithm to skip over NOPs with no line number when looking for the next instruction's lineno.

  • gh-109853: sys.path[0] is now set correctly for subinterpreters.

  • gh-109923: Set line number on the POP_TOP that follows a RETURN_GENERATOR.

  • gh-105716: Subinterpreters now correctly handle the case where they have threads running in the background. Before, such threads would interfere with cleaning up and destroying them, as well as prevent running another script.

  • gh-109369: The internal eval_breaker and supporting flags, plus the monitoring version have been merged into a single atomic integer to speed up checks.

  • gh-109823: Fix bug where compiler does not adjust labels when removing an empty basic block which is a jump target.

  • gh-109793: The main thread no longer exits prematurely when a subinterpreter is cleaned up during runtime finalization. The bug was a problem particularly because, when triggered, the 哋它亢 process would always return with a 0 exitcode, even if it failed.

  • gh-109719: Fix missing jump target labels when compiler reorders cold/warm blocks.

  • gh-109595: Add -X cpu_count command line option to override return results of os.cpu_count() and os.process_cpu_count(). This option is useful for users who need to limit CPU resources of a container system without having to modify the container (application code). Patch by Donghee Na.

  • gh-109627: Fix bug where the compiler does not assign a new jump target label to a duplicated small exit block.

  • gh-109596: Fix some tokens in the grammar that were incorrectly marked as soft keywords. Also fix some repeated rule names and ensure that repeated rules are not allowed. Patch by Pablo Galindo

  • gh-109496: On a 哋它亢 built in debug mode, Py_DECREF() now calls _Py_NegativeRefcount() if the object is a dangling pointer to deallocated memory: memory filled with 0xDD "dead byte" by the debug hook on memory allocators. The fix is to check the reference count before checking for _Py_IsImmortal(). Patch by Victor Stinner.

  • gh-107265: Deopt opcodes hidden by the executor when base opcode is needed

  • gh-109371: Deopted instructions correctly for tool initialization and modified the incorrect assertion in instrumentation, when a previous tool already sets INSTRUCTION events

  • gh-105658: Fix bug where the line trace of an except block ending with a conditional includes an excess event with the line of the conditional expression.

  • gh-109219: Fix compiling type param scopes that use a name which is also free in an inner scope.

  • gh-109351: Fix crash when compiling an invalid AST involving a named (walrus) expression.

  • gh-109341: Fix crash when compiling an invalid AST involving a ast.TypeAlias.

  • gh-109195: Fix source location for the LOAD_* instruction preceding a LOAD_SUPER_ATTR to load the super global (or shadowing variable) so that it encompasses only the name super and not the following parentheses.

  • gh-109256: Opcode IDs for specialized opcodes are allocated in their own range to improve stability of the IDs for the 'real' opcodes.

  • gh-109216: Fix possible memory leak in BUILD_MAP.

  • gh-109207: Fix a SystemError in __repr__ of symtable entry object.

  • gh-109179: Fix bug where the C traceback display drops notes from SyntaxError.

  • gh-109118: Disallow nested scopes (lambdas, generator expressions, and comprehensions) within PEP 695 annotation scopes that are nested within classes.

  • gh-109156: Add tests for de-instrumenting instructions while keeping the instrumentation for lines

  • gh-109114: Relax the detection of the error message for invalid lambdas inside f-strings to not search for arbitrary replacement fields to avoid false positives. Patch by Pablo Galindo

  • gh-105848: Add a new CALL_KW opcode, used for calls containing keyword arguments. Also, fix a possible crash when jumping over method calls in a debugger.

  • gh-109052: Use the base opcode when comparing code objects to avoid interference from instrumentation

  • gh-109118: Fix interpreter crash when a NameError is raised inside the type parameters of a generic class.

  • gh-88943: Improve syntax error for non-ASCII character that follows a numerical literal. It now points on the invalid non-ASCII character, not on the valid numerical literal.

  • gh-108976: Fix crash that occurs after de-instrumenting a code object in a monitoring callback.

  • gh-108732: Make iteration variables of module- and class-scoped comprehensions visible to pdb and other tools that use frame.f_locals again.

  • gh-108959: Fix caret placement for error locations for subscript and binary operations that involve non-semantic parentheses and spaces. Patch by Pablo Galindo

  • gh-104584: Fix a crash when running with 哋它亢UOPS or -X uops enabled and an error occurs during optimization.

  • gh-108727: Define tp_dealloc for CounterOptimizer_Type. This fixes a segfault on deallocation.

  • gh-108520: Fix multiprocessing.synchronize.SemLock.__setstate__() to properly initialize multiprocessing.synchronize.SemLock._is_fork_ctx. This fixes a regression when passing a SemLock across nested processes.

    Rename multiprocessing.synchronize.SemLock.is_fork_ctx to multiprocessing.synchronize.SemLock._is_fork_ctx to avoid exposing it as public API.

  • gh-108654: Restore locals shadowed by an inlined comprehension if the comprehension raises an exception.

  • gh-108488: Change the initialization of inline cache entries so that the cache entry for JUMP_BACKWARD is initialized to zero, instead of the adaptive_counter_warmup() value used for all other instructions. This counter, unique among instructions, counts up from zero.

  • gh-108716: Turn off deep-freezing of code objects. Modules are still frozen, so that a file system search is not needed for common modules.

  • gh-108614: Add RESUME_CHECK instruction, to avoid having to handle instrumentation, signals, and contexts switches in the tier 2 execution engine.

  • gh-108487: Move an assert that would cause a spurious crash in a devious case that should only trigger deoptimization.

  • gh-106176: Use a WeakValueDictionary to track the lists containing the modules each thread is currently importing. This helps avoid a reference leak from keeping the list around longer than necessary. Weakrefs are used as GC can't interrupt the cleanup.

  • gh-105481: The regen-opcode build stage was removed and its work is now done in regen-cases.

  • gh-107901: Fix missing line number on JUMP_BACKWARD at the end of a for loop.

  • gh-108113: The compile() built-in can now accept a new flag, ast.PyCF_OPTIMIZED_AST, which is similar to ast.PyCF_ONLY_AST except that the returned AST is optimized according to the value of the optimize argument.

    ast.parse() now accepts an optional argument optimize which is passed on to the compile() built-in. This makes it possible to obtain an optimized AST.

  • gh-107971: Opcode IDs are generated from bytecodes.c instead of being hard coded in opcode.py.

  • gh-107944: Improve error message for function calls with bad keyword arguments. Patch by Pablo Galindo

  • gh-108390: Raise an exception when setting a non-local event (RAISE, EXCEPTION_HANDLED, etc.) in sys.monitoring.set_local_events.

    Fixes crash when tracing in recursive calls to 哋它亢 classes.

  • gh-108035: Remove the _PyCFrame struct, moving the pointer to the current interpreter frame back to the threadstate, as it was for 3.10 and earlier. The _PyCFrame existed as a performance optimization for tracing. Since PEP 669 has been implemented, this optimization no longer applies.

  • gh-91051: Fix abort / segfault when using all eight type watcher slots, on platforms where char is signed by default.

  • gh-106581: Fix possible assertion failures and missing instrumentation events when 哋它亢UOPS or -X uops is enabled.

  • gh-107526: Revert converting vars, dir, next, getattr, and iter to argument clinic.

  • gh-84805: Autogenerate signature for METH_NOARGS and METH_O extension functions.

  • gh-107758: Make the dump_stack() routine used by the lltrace feature (low-level interpreter debugging) robust against recursion by ensuring that it never calls a __repr__ method implemented in 哋它亢. Also make the similar output for Tier-2 uops appear on stdout (instead of stderr), to match the lltrace code in ceval.c.

  • gh-107659: Add docstrings for ctypes.pointer() and ctypes.POINTER().

  • gh-105848: Modify the bytecode so that the actual callable for a CALL is at a consistent position on the stack (regardless of whether or not bound-method-calling optimizations are active).

  • gh-107674: Fixed performance regression in sys.settrace.

  • gh-107724: In pre-release versions of 3.12, up to rc1, the sys.monitoring callback function for the PY_THROW event was missing the third, exception argument. That is now fixed.

  • gh-84436: Skip reference count modifications for many known immortal objects.

  • gh-107596: Specialize subscripting str objects by int indexes.

  • gh-107080: Trace refs builds (--with-trace-refs) were crashing when used with isolated subinterpreters. The problematic global state has been isolated to each interpreter. Other fixing the crashes, this change does not affect users.

  • gh-107557: Generate the cases needed for the barebones tier 2 abstract interpreter for optimization passes in C哋它亢.

  • gh-106608: Make _PyUOpExecutorObject variable length.

  • gh-100964: Clear generators' exception state after return to break reference cycles.

  • gh-107455: Improve error messages when converting an incompatible type to ctypes.c_char_p, ctypes.c_wchar_p and ctypes.c_void_p.

  • gh-107263: Increase C recursion limit for functions other than the main interpreter from 800 to 1500. This should allow functions like list.__repr__ and json.dumps to handle all the inputs that they could prior to 3.12

  • gh-104584: Fix an issue which caused incorrect inline caches to be read when running with 哋它亢UOPS or -X uops enabled.

  • gh-104432: Fix potential unaligned memory access on C APIs involving returned sequences of char * pointers within the grp and socket modules. These were revealed using a -fsaniziter=alignment build on ARM macOS. Patch by Christopher Chavez.

  • gh-106078: Isolate _decimal (apply PEP 687). Patch by Charlie Zhao.

  • gh-106898: Add the exception as the third argument to PY_UNIND callbacks in sys.monitoring. This makes the PY_UNWIND callback consistent with the other exception handling callbacks.

  • gh-106895: Raise a ValueError when a monitoring callback function returns DISABLE for events that cannot be disabled locally.

  • gh-106897: Add a RERAISE event to sys.monitoring, which occurs when an exception is reraise, either explicitly by a plain raise statement, or implicitly in an except or finally block.

  • gh-77377: Ensure that multiprocessing synchronization objects created in a fork context are not sent to a different process created in a spawn context. This changes a segfault into an actionable RuntimeError in the parent process.

  • gh-106931: Statically allocated string objects are now interned globally instead of per-interpreter. This fixes a situation where such a string would only be interned in a single interpreter. Normal string objects are unaffected.

  • gh-104621: Unsupported modules now always fail to be imported.

  • gh-107122: Add dbm.ndbm.ndbm.clear() to dbm.ndbm. Patch By Donghee Na.

  • gh-107122: Add dbm.gnu.gdbm.clear() to dbm.gnu. Patch By Donghee Na.

  • gh-107015: The ASYNC and AWAIT tokens are removed from the Grammar, which removes the possibility of making async and await soft keywords when using feature_version<7 in ast.parse().

  • gh-106917: Fix classmethod-style super() method calls (i.e., where the second argument to super(), or the implied second argument drawn from self/cls in the case of zero-arg super, is a type) when the target of the call is not a classmethod.

  • gh-105699: 哋它亢 no longer crashes due an infrequent race when initializing per-interpreter interned strings. The crash would manifest when the interpreter was finalized.

  • gh-105699: 哋它亢 no longer crashes due to an infrequent race in setting Py_FileSystemDefaultEncoding and Py_FileSystemDefaultEncodeErrors (both deprecated), when simultaneously initializing two isolated subinterpreters. Now they are only set during runtime initialization.

  • gh-106908: Fix various hangs, reference leaks, test failures, and tracing/introspection bugs when running with 哋它亢UOPS or -X uops enabled.

  • gh-106092: Fix a segmentation fault caused by a use-after-free bug in frame_dealloc when the trashcan delays the deallocation of a PyFrameObject.

  • gh-106485: Reduce the number of materialized instances dictionaries by dematerializing them when possible.

  • gh-106719: No longer suppress arbitrary errors in the __annotations__ getter and setter in the type and module types.

  • gh-106723: Propagate frozen_modules to multiprocessing spawned process interpreters.

  • gh-104909: Split LOAD_ATTR_INSTANCE_VALUE into micro-ops.

  • gh-104909: Split LOAD_GLOBAL specializations into micro-ops.

  • gh-106597: A new debug structure of offsets has been added to the _PyRuntimeState that will help out-of-process debuggers and profilers to obtain the offsets to relevant interpreter structures in a way that is agnostic of how 哋它亢 was compiled and that doesn't require copying the headers. Patch by Pablo Galindo

  • gh-106487: Allow the count argument of str.replace() to be a keyword. Patch by Hugo van Kemenade.

  • gh-96844: Improve error message of list.remove(). Patch by Donghee Na.

  • gh-81283: Compiler now strips indents from docstrings. It reduces pyc file size 5% when the module is heavily documented. This change affects to __doc__ so tools like doctest will be affected.

  • gh-106396: When the format specification of an f-string expression is empty, the parser now generates an empty ast.JoinedStr node for it instead of an one-element ast.JoinedStr with an empty string ast.Constant.

  • gh-100288: Specialize LOAD_ATTR for non-descriptors on the class. Adds LOAD_ATTR_NONDESCRIPTOR_WITH_VALUES and LOAD_ATTR_NONDESCRIPTOR_NO_DICT.

  • gh-106008: Fix possible reference leaks when failing to optimize comparisons with None in the bytecode compiler.

  • gh-106145: Make end_lineno and end_col_offset required on type_param ast nodes.

  • gh-106213: Changed the way that Emscripten call trampolines work for compatibility with Wasm/JS Promise integration.

  • gh-106182: sys.getfilesystemencoding() and sys.getfilesystemencodeerrors now return interned Unicode object.

  • gh-106210: Removed Emscripten import trampoline as it was no longer necessary for Pyodide.

  • gh-104584: Added a new, experimental, tracing optimizer and interpreter (a.k.a. "tier 2"). This currently pessimizes, so don't use yet -- this is infrastructure so we can experiment with optimizing passes. To enable it, pass -Xuops or set 哋它亢UOPS=1. To get debug output, set 哋它亢UOPSDEBUG=N where N is a debug level (0-4, where 0 is no debug output and 4 is excessively verbose).

  • gh-105775: LOAD_CLOSURE is now a pseudo-op.

  • gh-105730: Allow any callable other than type objects as the condition predicate in BaseExceptionGroup.split() and BaseExceptionGroup.subgroup().

  • gh-105979: Fix crash in _imp.get_frozen_object() due to improper exception handling.

  • gh-106003: Add a new TO_BOOL instruction, which performs boolean conversions for POP_JUMP_IF_TRUE, POP_JUMP_IF_FALSE, and UNARY_NOT (which all expect exact bool values now). Also, modify the oparg of COMPARE_OP to include an optional "boolean conversion" flag.

  • gh-98931: Ensure custom SyntaxError error messages are raised for invalid imports with multiple targets. Patch by Pablo Galindo

  • gh-105724: Improve assert error messages by providing exact error range.

  • gh-105908: Fixed bug where gh-99111 breaks future import barry_as_FLUFL in the 哋它亢 REPL.

  • gh-105840: Fix possible crashes when specializing function calls with too many __defaults__.

  • gh-105831: Fix an f-string bug, where using a debug expression (the = sign) that appears in the last line of a file results to the debug buffer that holds the expression text being one character too small.

  • gh-105800: Correctly issue SyntaxWarning in f-strings if invalid sequences are used. Patch by Pablo Galindo

  • gh-105340: Include the comprehension iteration variable in locals() inside a module- or class-scope comprehension.

  • gh-105331: Raise ValueError if the delay argument to asyncio.sleep() is a NaN (matching time.sleep()).

  • gh-105587: The runtime can't guarantee that immortal objects will not be mutated by Extensions. Thus, this modifies _PyStaticObject_CheckRefcnt to warn instead of asserting.

  • gh-105564: Don't include artificil newlines in the line attribute of tokens in the APIs of the tokenize module. Patch by Pablo Galindo

  • gh-105549: Tokenize separately NUMBER and NAME tokens that are not ambiguous. Patch by Pablo Galindo.

  • gh-105588: Fix an issue that could result in crashes when compiling malformed ast nodes.

  • gh-100987: Allow objects other than code objects as the "executable" in internal frames. In the long term, this can help tools like Cython and PySpy interact more efficiently. In the shorter term, it allows us to perform some optimizations more simply.

  • gh-105375: Fix bugs in the builtins module where exceptions could end up being overwritten.

  • gh-105375: Fix bug in the compiler where an exception could end up being overwritten.

  • gh-105375: Improve error handling in PyUnicode_BuildEncodingMap() where an exception could end up being overwritten.

  • gh-105486: Change the repr of ParamSpec list of args in types.GenericAlias.

  • gh-105678: Break the MAKE_FUNCTION instruction into two parts, MAKE_FUNCTION which makes the function and SET_FUNCTION_ATTRIBUTE which sets the attributes on the function. This makes the stack effect of MAKE_FUNCTION regular to ease optimization and code generation.

  • gh-105435: Fix spurious newline character if file ends on a comment without a newline. Patch by Pablo Galindo

  • gh-105390: Correctly raise tokenize.TokenError exceptions instead of SyntaxError for tokenize errors such as incomplete input. Patch by Pablo Galindo

  • gh-105259: Don't include newline character for trailing NEWLINE tokens emitted in the tokenize module. Patch by Pablo Galindo

  • gh-104635: Eliminate redundant STORE_FAST instructions in the compiler. Patch by Donghee Na and Carl Meyer.

  • gh-105324: Fix the main function of the tokenize module when reading from sys.stdin. Patch by Pablo Galindo

  • gh-33092: Simplify and speed up interpreter for f-strings. Removes FORMAT_VALUE opcode. Add CONVERT_VALUE, FORMAT_SIMPLE and FORMAT_WITH_SPEC opcode. Compiler emits more efficient sequence for each format expression.

  • gh-105229: Remove remaining two-codeunit superinstructions. All remaining superinstructions only take a single codeunit, simplifying instrumentation and quickening.

  • gh-105235: Prevent out-of-bounds memory access during mmap.find() calls.

  • gh-98963: Restore the ability for a subclass of property to define __slots__ or otherwise be dict-less by ignoring failures to set a docstring on such a class. This behavior had regressed in 3.12beta1. An AttributeError where there had not previously been one was disruptive to existing code.

  • gh-104812: The "pending call" machinery now works for all interpreters, not just the main interpreter, and runs in all threads, not just the main thread. Some calls are still only done in the main thread, ergo in the main interpreter. This change does not affect signal handling nor the existing public C-API (Py_AddPendingCall()), which both still only target the main thread. The new functionality is meant strictly for internal use for now, since consequences of its use are not well understood yet outside some very restricted cases. This change brings the capability in line with the intention when the state was made per-interpreter several years ago.

  • gh-105194: Do not escape with backslashes f-string format specifiers. Patch by Pablo Galindo

  • gh-105229: Replace some dynamic superinstructions with single instruction equivalents.

  • gh-105162: Fixed bug in generator.close()/throw() where an inner iterator would be ignored when the outer iterator was instrumented.

  • gh-105164: Ensure annotations are set up correctly if the only annotation in a block is within a match block. Patch by Jelle Zijlstra.

  • gh-105148: Make _PyASTOptimizeState internal to ast_opt.c. Make _PyAST_Optimize take two integers instead of a pointer to this struct. This avoids the need to include pycore_compile.h in ast_opt.c.

  • gh-104799: Attributes of ast nodes that are lists now default to the empty list if omitted. This means that some code that previously raised TypeError when the AST node was used will now proceed with the empty list instead. Patch by Jelle Zijlstra.

  • gh-105111: Remove the old trashcan macros Py_TRASHCAN_SAFE_BEGIN and Py_TRASHCAN_SAFE_END. They should be replaced by the new macros Py_TRASHCAN_BEGIN and Py_TRASHCAN_END.

  • gh-105035: Fix super() calls on types with custom tp_getattro implementation (e.g. meta-types.)

  • gh-105017: Show CRLF lines in the tokenize string attribute in both NL and NEWLINE tokens. Patch by Marta Gómez.

  • gh-105013: Fix handling of multiline parenthesized lambdas in inspect.getsource(). Patch by Pablo Galindo

  • gh-105017: Do not include an additional final NL token when parsing files having CRLF lines. Patch by Marta Gómez.

  • gh-104976: Ensure that trailing DEDENT tokenize.TokenInfo objects emitted by the tokenize module are reported as in 哋它亢 3.11. Patch by Pablo Galindo

  • gh-104972: Ensure that the line attribute in tokenize.TokenInfo objects in the tokenize module are always correct. Patch by Pablo Galindo

  • gh-104955: Fix signature for the new __release_buffer__() slot. Patch by Jelle Zijlstra.

  • gh-104690: Starting new threads and process creation through os.fork() during interpreter shutdown (such as from atexit handlers) is no longer supported. It can lead to race condition between the main 哋它亢 runtime thread freeing thread states while internal threading routines are trying to allocate and use the state of just created threads. Or forked children trying to use the mid-shutdown runtime and thread state in the child process.

  • gh-104879: Fix crash when accessing the __module__ attribute of type aliases defined outside a module. Patch by Jelle Zijlstra.

  • gh-104825: Tokens emitted by the tokenize module do not include an implicit \n character in the line attribute anymore. Patch by Pablo Galindo

  • gh-104770: If a generator returns a value upon being closed, the value is now returned by generator.close().

  • gh-89091: Raise RuntimeWarning for unawaited async generator methods like asend(), athrow() and aclose(). Patch by Kumar Aditya.

  • gh-96663: Add a better, more introspect-able error message when setting attributes on classes without a __dict__ and no slot member for the attribute.

  • gh-93627: Update the 哋它亢 pickle module implementation to match the C implementation of the pickle module. For objects setting reduction methods like __reduce_ex__() or __reduce__() to None, pickling will result in a TypeError.

  • gh-101006: Improve error handling when read marshal data.

  • gh-91095: Specializes calls to most 哋它亢 classes. Specifically, any class that inherits from object, or another 哋它亢 class, and does not override __new__.

    The specialized instruction does the following:

    1. Creates the object (by calling object.__new__)

    2. Pushes a shim frame to the frame stack (to cleanup after __init__)

    3. Pushes the frame for __init__ to the frame stack

    Speeds up the instantiation of most 哋它亢 classes.

Library

  • gh-110786: sysconfig's CLI now ignores BrokenPipeError, making it exit normally if its output is being piped and the pipe closes.

  • gh-103480: The sysconfig module is now a package, instead of a single-file module.

  • gh-110733: Micro-optimization: Avoid calling min(), max() in BaseEventLoop._run_once().

  • gh-94597: Added asyncio.EventLoop for use with the asyncio.run() loop_factory kwarg to avoid calling the asyncio policy system.

  • gh-110682: runtime-checkable protocols used to consider __match_args__ a protocol member in __instancecheck__ if it was present on the protocol. Now, this attribute is ignored if it is present.

  • gh-110488: Fix a couple of issues in pathlib.PurePath.with_name(): a single dot was incorrectly considered a valid name, and in PureWindowsPath, a name with an NTFS alternate data stream, like a:b, was incorrectly considered invalid.

  • gh-110590: Fix a bug in _sre.compile() where TypeError would be overwritten by OverflowError when the code argument was a list of non-ints.

  • gh-65052: Prevent pdb from crashing when trying to display undisplayable objects

  • gh-110519: Deprecation warning about non-integer number in gettext now always refers to the line in the user code where gettext function or method is used. Previously it could refer to a line in gettext code.

  • gh-89902: Deprecate non-standard format specifier "N" for decimal.Decimal. It was not documented and only supported in the C implementation.

  • gh-110378: contextmanager() and asynccontextmanager() context managers now close an invalid underlying generator object that yields more then one value.

  • gh-106670: In pdb, set convenience variable $_exception for post mortem debugging.

  • gh-110365: Fix termios.tcsetattr() bug that was overwriting existing errors during parsing integers from term list.

  • gh-109653: Slightly improve the import time of several standard-library modules by deferring imports of warnings within those modules. Patch by Alex Waygood.

  • gh-110273: dataclasses.replace() now raises TypeError instead of ValueError if specify keyword argument for a field declared with init=False or miss keyword argument for required InitVar field.

  • gh-110249: Add --inline-caches flag to dis command line.

  • gh-109653: Fix a 哋它亢 3.12 regression in the import time of random. Patch by Alex Waygood.

  • gh-110222: Add support of struct sequence objects in copy.replace(). Patched by Xuehai Pan.

  • gh-109649: multiprocessing, concurrent.futures, compileall: Replace os.cpu_count() with os.process_cpu_count() to select the default number of worker threads and processes. Get the CPU affinity if supported. Patch by Victor Stinner.

  • gh-110150: Fix base case handling in statistics.quantiles. Now allows a single data point.

  • gh-110036: On Windows, multiprocessing Popen.terminate() now catches PermissionError and get the process exit code. If the process is still running, raise again the PermissionError. Otherwise, the process terminated as expected: store its exit code. Patch by Victor Stinner.

  • gh-110038: Fixed an issue that caused KqueueSelector.select() to not return all the ready events in some cases when a file descriptor is registered for both read and write.

  • gh-110045: Update the symtable module to support the new scopes introduced by PEP 695.

  • gh-88402: Add new variables to sysconfig.get_config_vars() on Windows: LIBRARY, LDLIBRARY, LIBDIR, SOABI, and Py_NOGIL.

  • gh-109631: re functions such as re.findall(), re.split(), re.search() and re.sub() which perform short repeated matches can now be interrupted by user.

  • gh-109653: Reduce the import time of email.utils by around 43%. This results in the import time of email.message falling by around 18%, which in turn reduces the import time of importlib.metadata by around 6%. Patch by Alex Waygood.

  • gh-109818: Fix reprlib.recursive_repr() not copying __type_params__ from decorated function.

  • gh-109047: concurrent.futures: The executor manager thread now catches exceptions when adding an item to the call queue. During 哋它亢 finalization, creating a new thread can now raise RuntimeError. Catch the exception and call terminate_broken() in this case. Patch by Victor Stinner.

  • gh-109782: Ensure the signature of os.path.isdir() is identical on all platforms. Patch by Amin Alaee.

  • gh-109653: Improve import time of functools by around 13%. Patch by Alex Waygood.

  • gh-109590: shutil.which() will prefer files with an extension in PATHEXT if the given mode includes os.X_OK on win32. If no PATHEXT match is found, a file without an extension in PATHEXT can be returned. This change will have shutil.which() act more similarly to previous behavior in 哋它亢 3.11.

  • gh-109653: Reduce the import time of enum by over 50%. Patch by Alex Waygood.

  • gh-109593: Avoid deadlocking on a reentrant call to the multiprocessing resource tracker. Such a reentrant call, though unlikely, can happen if a GC pass invokes the finalizer for a multiprocessing object such as SemLock.

  • gh-109653: Reduce the import time of typing by around a third. Patch by Alex Waygood.

  • gh-109649: Add os.process_cpu_count() function to get the number of logical CPUs usable by the calling thread of the current process. Patch by Victor Stinner.

  • gh-74481: Add set_error_mode related constants in msvcrt module in 哋它亢 debug build.

  • gh-109613: Fix os.stat() and os.DirEntry.stat(): check for exceptions. Previously, on 哋它亢 built in debug mode, these functions could trigger a fatal 哋它亢 error (and abort the process) when a function succeeded with an exception set. Patch by Victor Stinner.

  • gh-109599: Expose the type of PyCapsule objects as types.CapsuleType.

  • gh-109109: You can now get the raw TLS certificate chains from TLS connections via ssl.SSLSocket.get_verified_chain() and ssl.SSLSocket.get_unverified_chain() methods.

    Contributed by Mateusz Nowak.

  • gh-109559: Update unicodedata database to Unicode 15.1.0.

  • gh-109543: Remove unnecessary hasattr() check during typing.TypedDict creation.

  • gh-109495: Remove unnecessary extra __slots__ in datetime's pure 哋它亢 implementation to reduce memory size, as they are defined in the superclass. Patch by James Hilton-Balfe

  • gh-109461: logging: Use a context manager for lock acquisition.

  • gh-109096: http.server.CGIHTTPRequestHandler has been deprecated for removal in 3.15. Its design is old and the web world has long since moved beyond CGI.

  • gh-109409: Fix error when it was possible to inherit a frozen dataclass from multiple parents some of which were possibly not frozen.

  • gh-109375: The pdb alias command now prevents registering aliases without arguments.

  • gh-109319: Deprecate the dis.HAVE_ARGUMENT field in favour of dis.hasarg.

  • gh-107219: Fix a race condition in concurrent.futures. When a process in the process pool was terminated abruptly (while the future was running or pending), close the connection write end. If the call queue is blocked on sending bytes to a worker process, closing the connection write end interrupts the send, so the queue can be closed. Patch by Victor Stinner.

  • gh-66143: The codecs.CodecInfo object has been made copyable and pickleable. Patched by Robert Lehmann and Furkan Onder.

  • gh-109187: pathlib.Path.resolve() now treats symlink loops like other errors: in strict mode, OSError is raised, and in non-strict mode, no exception is raised.

  • gh-50644: Attempts to pickle or create a shallow or deep copy of codecs streams now raise a TypeError. Previously, copying failed with a RecursionError, while pickling produced wrong results that eventually caused unpickling to fail with a RecursionError.

  • gh-109174: Add support of types.SimpleNamespace in copy.replace().

  • gh-109164: pdb: Replace getopt with argparse for parsing command line arguments.

  • gh-109151: Enable readline editing features in the sqlite3 command-line interface (哋它亢 -m sqlite3).

  • gh-108987: Fix _thread.start_new_thread() race condition. If a thread is created during 哋它亢 finalization, the newly spawned thread now exits immediately instead of trying to access freed memory and lead to a crash. Patch by Victor Stinner.

  • gh-108682: Enum: require names=() or type=... to create an empty enum using the functional syntax.

  • gh-109033: Exceptions raised by os.utime builtin function now include the related filename

  • gh-108843: Fix an issue in ast.unparse() when unparsing f-strings containing many quote types.

  • gh-108469: ast.unparse() now supports new f-string syntax introduced in 哋它亢 3.12. Note that the f-string quotes are reselected for simplicity under the new syntax. (Patch by Steven Sun)

  • gh-108751: Add copy.replace() function which allows to create a modified copy of an object. It supports named tuples, dataclasses, and many other objects.

  • gh-108682: Enum: raise TypeError if super().__new__() is called from a custom __new__.

  • gh-108278: Deprecate passing the callback callable by keyword for the following sqlite3.Connection APIs:

    The affected parameters will become positional-only in 哋它亢 3.15.

    Patch by Erlend E. Aasland.

  • gh-105829: Fix concurrent.futures.ProcessPoolExecutor deadlock

  • gh-108295: Fix crashes related to use of weakrefs on typing.TypeVar.

  • gh-108463: Make expressions/statements work as expected in pdb

  • gh-108277: Add os.timerfd_create(), os.timerfd_settime(), os.timerfd_gettime(), os.timerfd_settime_ns(), and os.timerfd_gettime_ns() to provide a low level interface for Linux's timer notification file descriptor.

  • gh-107811: tarfile: extraction of members with overly large UID or GID (e.g. on an OS with 32-bit id_t) now fails in the same way as failing to set the ID.

  • gh-64662: Fix support for virtual tables in sqlite3.Connection.iterdump(). Patch by Aviv Palivoda.

  • gh-108111: Fix a regression introduced in gh-101251 for 3.12, resulting in an incorrect offset calculation in gzip.GzipFile.seek().

  • gh-108294: time.sleep() now raises an auditing event.

  • gh-108278: Deprecate passing name, number of arguments, and the callable as keyword arguments, for the following sqlite3.Connection APIs:

    The affected parameters will become positional-only in 哋它亢 3.15.

    Patch by Erlend E. Aasland.

  • gh-108322: Speed-up NormalDist.samples() by using the inverse CDF method instead of calling random.gauss().

  • gh-83417: Add the ability for venv to create a .gitignore file which causes the created environment to be ignored by Git. It is on by default when venv is called via its CLI.

  • gh-105736: Harmonized the pure 哋它亢 version of OrderedDict with the C version. Now, both versions set up their internal state in __new__. Formerly, the pure 哋它亢 version did the set up in __init__.

  • gh-108083: Fix bugs in the constructor of sqlite3.Connection and sqlite3.Connection.close() where exceptions could be leaked. Patch by Erlend E. Aasland.

  • gh-107932: Fix dis module to properly report and display bytecode that do not have source lines.

  • gh-105539: sqlite3 now emits an ResourceWarning if a sqlite3.Connection object is not closed explicitly. Patch by Erlend E. Aasland.

  • gh-107995: The __module__ attribute on instances of functools.cached_property is now set to the name of the module in which the cached_property is defined, rather than "functools". This means that doctests in cached_property docstrings are now properly collected by the doctest module. Patch by Tyler Smart.

  • gh-107963: Fix multiprocessing.set_forkserver_preload() to check the given list of modules names. Patch by Donghee Na.

  • gh-106242: Fixes os.path.normpath() to handle embedded null characters without truncating the path.

  • gh-81555: xml.dom.minidom now only quotes " in attributes.

  • gh-50002: xml.dom.minidom now preserves whitespaces in attributes.

  • gh-93057: Passing more than one positional argument to sqlite3.connect() and the sqlite3.Connection constructor is deprecated. The remaining parameters will become keyword-only in 哋它亢 3.15. Patch by Erlend E. Aasland.

  • gh-76913: Add merge_extra parameter/feature to logging.LoggerAdapter

  • gh-107913: Fix possible losses of errno and winerror values in OSError exceptions if they were cleared or modified by the cleanup code before creating the exception object.

  • gh-107845: tarfile.data_filter() now takes the location of symlinks into account when determining their target, so it will no longer reject some valid tarballs with LinkOutsideDestinationError.

  • gh-107812: Extend socket's netlink support to the FreeBSD platform.

  • gh-107805: Fix signatures of module-level generated functions in turtle.

  • gh-107782: pydoc is now able to show signatures which are not representable in 哋它亢, e.g. for getattr and dict.pop.

  • gh-56166: Deprecate passing optional arguments maxsplit, count and flags in module-level functions re.split(), re.sub() and re.subn() as positional. They should only be passed by keyword.

  • gh-107710: Speed up logging.getHandlerNames().

  • gh-107715: Fix doctest.DocTestFinder.find() in presence of class names with special characters. Patch by Gertjan van Zwieten.

  • gh-100814: Passing a callable object as an option value to a Tkinter image now raises the expected TclError instead of an AttributeError.

  • gh-72684: Add tkinter widget methods: tk_busy_hold(), tk_busy_configure(), tk_busy_cget(), tk_busy_forget(), tk_busy_current(), and tk_busy_status().

  • gh-106684: Raise ResourceWarning when asyncio.StreamWriter is not closed leading to memory leaks. Patch by Kumar Aditya.

  • gh-107465: Add pathlib.Path.from_uri() classmethod.

  • gh-107077: Seems that in some conditions, OpenSSL will return SSL_ERROR_SYSCALL instead of SSL_ERROR_SSL when a certification verification has failed, but the error parameters will still contain ERR_LIB_SSL and SSL_R_CERTIFICATE_VERIFY_FAILED. We are now detecting this situation and raising the appropriate ssl.SSLCertVerificationError. Patch by Pablo Galindo

  • gh-107576: Fix types.get_original_bases() to only return __orig_bases__ if it is present on cls directly. Patch by James Hilton-Balfe.

  • gh-105481: Remove opcode.is_pseudo, opcode.MIN_PSEUDO_OPCODE and opcode.MAX_PSEUDO_OPCODE, which were added in 3.12, were never documented and were not intended to be used externally.

  • gh-105481: opcode.ENABLE_SPECIALIZATION (which was added in 3.12 but never documented or intended for external usage) is moved to _opcode.ENABLE_SPECIALIZATION where tests can access it.

  • gh-107396: tarfiles; Fixed use before assignment of self.exception for gzip decompression

  • gh-107409: Set __wrapped__ attribute in reprlib.recursive_repr().

  • gh-107406: Implement new __repr__() method for struct.Struct. Now it returns Struct(<format repr>).

  • gh-107369: Optimize textwrap.indent(). It is ~30% faster for large input. Patch by Inada Naoki.

  • gh-78722: Fix issue where pathlib.Path.iterdir() did not raise OSError until iterated.

  • gh-105578: Deprecate typing.AnyStr in favor of the new Type Parameter syntax. See PEP 695.

  • gh-62519: Make gettext.pgettext() search plural definitions when translation is not found.

  • gh-107089: Shelves opened with shelve.open() have a much faster clear() method. Patch by James Cave.

  • gh-82500: Fix overflow on 32-bit systems with asyncio os.sendfile() implementation.

  • gh-83006: Document behavior of shutil.disk_usage() for non-mounted filesystems on Unix.

  • gh-65495: Use lowercase mail from and rcpt to in smptlib.SMTP.

  • gh-106186: Do not report MultipartInvariantViolationDefect defect when the email.parser.Parser class is used to parse emails with headersonly=True.

  • gh-105002: Fix invalid result from PurePath.relative_to() method when attempting to walk a ".." segment in other with walk_up enabled. A ValueError exception is now raised in this case.

  • gh-106739: Add the rtype_cache to the warning message (as an addition to the type of leaked objects and the number of leaked objects already included in the message) to make debugging leaked objects easier when the multiprocessing resource tracker process finds leaked objects at shutdown. This helps more quickly identify what was leaked and/or why the leaked object was not properly cleaned up.

  • gh-106751: Optimize SelectSelector.select() for many iteration case. Patch By Donghee Na.

  • gh-106751: Optimize _PollLikeSelector.select() for many iteration case.

  • gh-106751: Optimize KqueueSelector.select() for many iteration case. Patch By Donghee Na.

  • gh-106831: Fix potential missing NULL check of d2i_SSL_SESSION result in _ssl.c.

  • gh-105481: The various opcode lists in the dis module are now generated from bytecodes.c instead of explicitly constructed in opcode.py.

  • gh-106727: Make inspect.getsource() smarter for class for same name definitions

  • gh-106789: Remove import of pprint from sysconfig.

  • gh-105726: Added __slots__ to contextlib.AbstractContextManager and contextlib.AbstractAsyncContextManager so that child classes can use __slots__.

  • gh-106774: Update the bundled copy of pip to version 23.2.1.

  • gh-106751: selectors: Optimize EpollSelector.select() code by moving some code outside of the loop.

  • gh-106752: Fixed several bugs in zipfile.Path, including: in zipfile.Path.match(), Windows separators are no longer honored (and never were meant to be); Fixed name/suffix/suffixes/stem operations when no filename is present and the Path is not at the root of the zipfile; Reworked glob for performance and more correct matching behavior.

  • gh-105293: Remove call to SSL_CTX_set_session_id_context during client side context creation in the ssl module.

  • gh-106734: Disable tab completion in multiline mode of pdb

  • gh-105481: Expose opcode metadata through _opcode.

  • gh-106670: Add the new exceptions command to the Pdb debugger. It makes it possible to move between chained exceptions when using post mortem debugging.

  • gh-106602: Add __copy__ and __deepcopy__ in enum

  • gh-106664: selectors: Add _SelectorMapping.get() method and optimize _SelectorMapping.__getitem__().

  • gh-106628: Speed up parsing of emails by about 20% by not compiling a new regular expression for every single email.

  • gh-89427: Set the environment variable VIRTUAL_ENV_PROMPT at venv activation, even when VIRTUAL_ENV_DISABLE_PROMPT is set.

  • gh-106530: Revert a change to colorsys.rgb_to_hls() that caused division by zero for certain almost-white inputs. Patch by Terry Jan Reedy.

  • gh-106584: Fix exit code for unittest if all tests are skipped. Patch by Egor Eliseev.

  • gh-106566: Optimize (?!) (pattern which always fails) in regular expressions.

  • gh-106554: selectors: Reduce Selector overhead by using a dict.get() to lookup file descriptors.

  • gh-106558: Remove ref cycle in callers of convert_to_error() by deleting result from scope in a finally block.

  • gh-100502: Add pathlib.PurePath.pathmod class attribute that stores the implementation of os.path used for low-level path operations: either posixpath or ntpath.

  • gh-106527: Reduce overhead to add and remove asyncio readers and writers.

  • gh-106524: Fix crash in _sre.template() with templates containing invalid group indices.

  • gh-106531: Removed _legacy and the names it provided from importlib.resources: Resource, contents, is_resource, open_binary, open_text, path, read_binary, and read_text.

  • gh-106052: re module: fix the matching of possessive quantifiers in the case of a subpattern containing backtracking.

  • gh-106510: Improve debug output for atomic groups in regular expressions.

  • gh-106503: Fix ref cycle in asyncio._SelectorSocketTransport by removing _write_ready in close.

  • gh-105497: Fix flag mask inversion when unnamed flags exist.

  • gh-90876: Prevent multiprocessing.spawn from failing to import in environments where sys.executable is None. This regressed in 3.11 with the addition of support for path-like objects in multiprocessing.

  • gh-106403: Instances of typing.TypeVar, typing.ParamSpec, typing.ParamSpecArgs, typing.ParamSpecKwargs, and typing.TypeVarTuple once again support weak references, fixing a regression introduced in 哋它亢 3.12.0 beta 1. Patch by Jelle Zijlstra.

  • gh-89812: Add private pathlib._PathBase class, which provides experimental support for virtual filesystems, and may be made public in a future version of 哋它亢.

  • gh-106292: Check for an instance-dict cached value in the __get__() method of functools.cached_property(). This better matches the pre-3.12 behavior and improves compatibility for users subclassing functools.cached_property() and adding a __set__() method.

  • gh-106350: Detect possible memory allocation failure in the libtommath function mp_init() used by the _tkinter module.

  • gh-106330: Fix incorrect matching of empty paths in pathlib.PurePath.match(). This bug was introduced in 哋它亢 3.12.0 beta 1.

  • gh-106309: Deprecate typing.no_type_check_decorator(). No major type checker ever added support for this decorator. Patch by Alex Waygood.

  • gh-102541: Make pydoc.doc() catch bad module ImportError when output stream is not None.

  • gh-106263: Fix crash when calling repr with a manually constructed SignalDict object. Patch by Charlie Zhao.

  • gh-106236: Replace assert statements with raise RuntimeError in threading, so that _DummyThread cannot be joined even with -OO.

  • gh-106238: Fix rare concurrency bug in lock acquisition by the logging package.

  • gh-106152: Added PY_THROW event hook for cProfile for generators

  • gh-106075: Added asyncio.taskgroups.__all__ to asyncio.__all__ for export in star imports.

  • gh-104527: Zipapp will now skip over appending an archive to itself.

  • gh-106046: Improve the error message from os.fspath() if called on an object where __fspath__ is set to None. Patch by Alex Waygood.

  • gh-105987: Fix crash due to improper reference counting in asyncio eager task factory internal routines.

  • gh-105974: Fix bug where a typing.Protocol class that had one or more non-callable members would raise TypeError when issubclass() was called against it, even if it defined a custom __subclasshook__ method. The behaviour in 哋它亢 3.11 and lower -- which has now been restored -- was not to raise TypeError in these situations if a custom __subclasshook__ method was defined. Patch by Alex Waygood.

  • gh-96145: Reverted addition of json.AttrDict.

  • gh-89812: Add pathlib.UnsupportedOperation, which is raised instead of NotImplementedError when a path operation isn't supported.

  • gh-105808: Fix a regression introduced in gh-101251 for 3.12, causing gzip.GzipFile.flush() to not flush the compressor (nor pass along the zip_mode argument).

  • gh-105481: stack_effect() no longer raises an exception if an oparg is provided for an opcode that doesn't use its arg, or when it is not provided for an opcode that does use it. In the latter case, the stack effect is returned for oparg=0.

  • gh-104799: Enable ast.unparse() to unparse function and class definitions created without the new type_params field from PEP 695. Patch by Jelle Zijlstra.

  • gh-105793: Add follow_symlinks keyword-only argument to pathlib.Path.is_dir() and is_file(), defaulting to True.

  • gh-105570: Deprecate two methods of creating typing.TypedDict classes with 0 fields using the functional syntax: TD = TypedDict("TD") and TD = TypedDict("TD", None). Both will be disallowed in 哋它亢 3.15. To create a TypedDict class with 0 fields, either use class TD(TypedDict): pass or TD = TypedDict("TD", {}).

  • gh-105745: Fix webbrowser.Konqueror.open method.

  • gh-105733: ctypes: Deprecate undocumented ctypes.SetPointerType() and ctypes.ARRAY() functions. Patch by Victor Stinner.

  • gh-105687: Remove deprecated re.template, re.T, re.TEMPLATE, sre_constans.SRE_FLAG_TEMPLATE.

  • gh-105684: Supporting asyncio.Task.set_name() is now mandatory for third party task implementations. The undocumented _set_task_name() function (deprecated since 3.8) has been removed. Patch by Kumar Aditya.

  • gh-105375: Fix a bug in _Unpickler_SetInputStream() where an exception could end up being overwritten in case of failure.

  • gh-105626: Change the default return value of http.client.HTTPConnection.get_proxy_response_headers() to be None and not {}.

  • gh-105375: Fix bugs in sys where exceptions could end up being overwritten because of deferred error handling.

  • gh-105605: Harden pyexpat error handling during module initialisation to prevent exceptions from possibly being overwritten, and objects from being dereferenced twice.

  • gh-105375: Fix bug in decimal where an exception could end up being overwritten.

  • gh-105375: Fix bugs in _datetime where exceptions could be overwritten in case of module initialisation failure.

  • gh-105375: Fix bugs in _ssl initialisation which could lead to leaked references and overwritten exceptions.

  • gh-105375: Fix a bug in array.array where an exception could end up being overwritten.

  • gh-105375: Fix bugs in _ctypes where exceptions could end up being overwritten.

  • gh-105375: Fix a bug in the posix module where an exception could be overwritten.

  • gh-105375: Fix bugs in _elementtree where exceptions could be overwritten.

  • gh-105375: Fix bugs in zoneinfo where exceptions could be overwritten.

  • gh-105375: Fix bugs in errno where exceptions could be overwritten.

  • gh-105566: Deprecate creating a typing.NamedTuple class using keyword arguments to denote the fields (NT = NamedTuple("NT", x=int, y=str)). This will be disallowed in 哋它亢 3.15. Use the class-based syntax or the functional syntax instead.

    Two methods of creating NamedTuple classes with 0 fields using the functional syntax are also deprecated, and will be disallowed in 哋它亢 3.15: NT = NamedTuple("NT") and NT = NamedTuple("NT", None). To create a NamedTuple class with 0 fields, either use class NT(NamedTuple): pass or NT = NamedTuple("NT", []).

  • gh-105545: Remove deprecated in 3.11 webbrowser.MacOSXOSAScript._name attribute.

  • gh-105497: Fix flag inversion when alias/mask members exist.

  • gh-105509: typing.Annotated is now implemented as an instance of typing._SpecialForm rather than a class. This should have no user-facing impact for users of the typing module public API.

  • gh-105375: Fix bugs in pickle where exceptions could be overwritten.

  • gh-70303: Emit FutureWarning from pathlib.Path.glob() and rglob() if the given pattern ends with "**". In a future 哋它亢 release, patterns with this ending will match both files and directories. Add a trailing slash to only match directories.

  • gh-105375: Fix a bug in sqlite3 where an exception could be overwritten in the collation callback.

  • gh-105382: Remove cafile, capath and cadefault parameters of the urllib.request.urlopen() function, deprecated in 哋它亢 3.6. Patch by Victor Stinner.

  • gh-105376: logging: Remove undocumented and untested Logger.warn() and LoggerAdapter.warn() methods and logging.warn() function. Deprecated since 哋它亢 3.3, they were aliases to the logging.Logger.warning() method, logging.LoggerAdapter.warning() method and logging.warning() function. Patch by Victor Stinner.

  • gh-105332: Revert pickling method from by-name back to by-value.

  • gh-104554: Add RTSPS scheme support in urllib.parse

  • gh-105292: Add option to traceback.format_exception_only() to recurse into the nested exception of a BaseExceptionGroup.

  • gh-105280: Fix bug where isinstance([], collections.abc.Mapping) could evaluate to True if garbage collection happened at the wrong time. The bug was caused by changes to the implementation of typing.Protocol in 哋它亢 3.12.

  • gh-80480: array: Add 'w' typecode that represents Py_UCS4.

  • gh-105239: Fix longstanding bug where issubclass(object, typing.Protocol) would evaluate to True in some edge cases. Patch by Alex Waygood.

  • gh-104310: In the beta 1 release we added a utility function for extension module authors, to use when testing their module for support in multiple interpreters or under a per-interpreter GIL. The name of that function has changed from allowing_all_extensions to _incompatible_extension_module_restrictions. The default for the "disable_check" argument has change from True to False, to better match the new function name.

  • gh-105080: Fixed inconsistent signature on derived classes for inspect.signature()

  • gh-105144: Fix a recent regression in the typing module. The regression meant that doing class Foo(X, typing.Protocol), where X was a class that had abc.ABCMeta as its metaclass, would then cause subsequent isinstance(1, X) calls to erroneously raise TypeError. Patch by Alex Waygood.

  • gh-62948: The io.IOBase finalizer now logs the close() method errors with sys.unraisablehook. Previously, errors were ignored silently by default, and only logged in 哋它亢 Development Mode or on 哋它亢 built on debug mode. Patch by Victor Stinner.

  • gh-105096: wave: Deprecate the getmark(), setmark() and getmarkers() methods of the wave.Wave_read and wave.Wave_write classes. They will be removed in 哋它亢 3.15. Patch by Victor Stinner.

  • gh-104992: Remove the untested and undocumented unittest.TestProgram.usageExit() method, deprecated in 哋它亢 3.11. Patch by Hugo van Kemenade.

  • gh-104996: Improve performance of pathlib.PurePath initialisation by deferring joining of paths when multiple arguments are given.

  • gh-101588: Deprecate undocumented copy/deepcopy/pickle support for itertools.

  • gh-103631: Fix pathlib.PurePosixPath(pathlib.PureWindowsPath(...)) not converting path separators to restore 3.11 compatible behavior.

  • gh-104947: Make comparisons between pathlib.PureWindowsPath objects consistent across Windows and Posix to match 3.11 behavior.

  • gh-104773: PEP 594: Remove the audioop module, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104773: PEP 594: Remove the aifc module, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104773: PEP 594: Remove the uu module, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104935: Fix bugs with the interaction between typing.runtime_checkable() and typing.Generic that were introduced by the PEP 695 implementation. Patch by Jelle Zijlstra.

  • gh-104773: PEP 594: Remove the crypt module and its private _crypt extension, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104773: PEP 594: Remove the nis module, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104898: Add missing __slots__ to os.PathLike.

  • gh-104773: PEP 594: Remove the xdrlib module, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104773: PEP 594: Remove the nntplib module, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104886: Remove the undocumented configparser.LegacyInterpolation class, deprecated in the docstring since 哋它亢 3.2, and with a deprecation warning since 哋它亢 3.11. Patch by Hugo van Kemenade.

  • gh-104786: Remove kwargs-based typing.TypedDict creation

  • gh-104876: Remove the turtle.RawTurtle.settiltangle() method, deprecated in docs since 哋它亢 3.1 and with a deprecation warning since 哋它亢 3.11. Patch by Hugo van Kemenade.

  • gh-104773: PEP 594: Removed the msilib package, deprecated in 哋它亢 3.11.

  • gh-104773: PEP 594: Remove the spwd module, deprecated in 哋它亢 3.11: the 哋它亢-pam project can be used instead. Patch by Victor Stinner.

  • gh-75552: Removed the tkinter.tix module, deprecated since 哋它亢 3.6.

  • gh-104773: PEP 594: Remove the chunk module, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104773: PEP 594: Remove the mailcap module, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104773: PEP 594: Remove the sunau module, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104780: PEP 594: Remove the ossaudiodev module, deprecated in 哋它亢 3.11. Patch Victor Stinner.

  • gh-104773: PEP 594: Remove the pipes module, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104873: Add typing.get_protocol_members() to return the set of members defining a typing.Protocol. Add typing.is_protocol() to check whether a class is a typing.Protocol. Patch by Jelle Zijlstra.

  • gh-104874: Document the __name__ and __supertype__ attributes of typing.NewType. Patch by Jelle Zijlstra.

  • gh-104835: Removed the following unittest functions, deprecated in 哋它亢 3.11:

    • unittest.findTestCases()

    • unittest.makeSuite()

    • unittest.getTestCaseNames()

    Use TestLoader methods instead:

    Patch by Hugo van Kemenade.

  • gh-104804: Remove the untested and undocumented webbrowser MacOSX class, deprecated in 哋它亢 3.11. Patch by Hugo van Kemenade.

  • gh-83863: Support for using pathlib.Path objects as context managers has been removed. Before 哋它亢 3.9, exiting the context manager marked a path as "closed", which caused some (but not all!) methods to raise when called. Since 哋它亢 3.9, using a path as a context manager does nothing.

  • gh-104799: Adjust the location of the (see PEP 695) type_params field on ast.ClassDef, ast.AsyncFunctionDef, and ast.FunctionDef to better preserve backward compatibility. Patch by Jelle Zijlstra

  • gh-104797: Allow typing.Protocol classes to inherit from collections.abc.Buffer. Patch by Jelle Zijlstra.

  • gh-104783: Remove locale.resetlocale() function deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104780: Remove the 2to3 program and the lib2to3 module, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104773: PEP 594: Remove the telnetlib module, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104773: PEP 594: Remove the imghdr module, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104773: PEP 594: Remove the cgi and cgitb modules, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104773: PEP 594: Remove the sndhdr module, deprecated in 哋它亢 3.11. Patch by Victor Stinner.

  • gh-104372: On Linux where subprocess can use the vfork() syscall for faster spawning, prevent the parent process from blocking other threads by dropping the GIL while it waits for the vfork'ed child process exec() outcome. This prevents spawning a binary from a slow filesystem from blocking the rest of the application.

  • gh-99108: We now release the GIL around built-in hashlib computations of reasonable size for the SHA families and MD5 hash functions, matching what our OpenSSL backed hash computations already does.

  • gh-102613: Improve performance of pathlib.Path.glob() when expanding a pattern with a non-terminal "**" component by filtering walked paths through a regular expression, rather than calling os.scandir() more than once on each directory.

  • gh-104399: Prepare the _tkinter module for building with Tcl 9.0 and future libtommath by replacing usage of deprecated functions mp_to_unsigned_bin_n() and mp_unsigned_bin_size() when necessary.

  • gh-102676: Add fields start_offset, cache_offset, end_offset, baseopname, baseopcode, jump_target and oparg to dis.Instruction.

  • gh-103558: Fixed parent argument validation mechanism of argparse. Improved test coverage.

  • gh-103464: Provide helpful usage messages when parsing incorrect pdb commands.

  • gh-103384: Generalize the regex pattern BaseConfigurator.INDEX_PATTERN to allow spaces and non-alphanumeric characters in keys.

  • gh-103124: Added multiline statement support for pdb

  • gh-101162: Forbid using builtins.issubclass() with types.GenericAlias as the first argument.

  • gh-103200: Fix cache repopulation semantics of zipimport.invalidate_caches(). The cache is now repopulated upon retrieving files with an invalid cache, not when the cache is invalidated.

  • gh-100061: Fix a bug that causes wrong matches for regular expressions with possessive qualifier.

  • gh-77609: Add follow_symlinks argument to pathlib.Path.glob() and rglob(), defaulting to false.

  • gh-102541: Hide traceback in help() prompt, when import failed.

  • gh-102120: Added a stream mode to tarfile that allows for reading archives without caching info about the inner files.

  • gh-102029: Deprecate passing any arguments to threading.RLock().

  • gh-88233: Refactored zipfile._strip_extra to use higher level abstractions for extras instead of a heavy-state loop.

  • gh-102024: Reduce calls of _idle_semaphore.release() in concurrent.futures.thread._worker().

  • gh-73435: Add support for recursive wildcards in pathlib.PurePath.match().

  • gh-84867: unittest.TestLoader no longer loads test cases from exact unittest.TestCase and unittest.FunctionTestCase classes.

  • gh-99203: Restore following C哋它亢 <= 3.10.5 behavior of shutil.make_archive(): do not create an empty archive if root_dir is not a directory, and, in that case, raise FileNotFoundError or NotADirectoryError regardless of format choice. Beyond the brought-back behavior, the function may now also raise these exceptions in dry_run mode.

  • gh-80480: Emit DeprecationWarning for array's 'u' type code, deprecated in docs since 哋它亢 3.3.

  • gh-94924: unittest.mock.create_autospec() now properly returns coroutine functions compatible with inspect.iscoroutinefunction()

  • gh-94777: Fix hanging multiprocessing ProcessPoolExecutor when a child process crashes while data is being written in the call queue.

  • gh-92871: Remove the typing.io and typing.re namespaces, deprecated since 哋它亢 3.8. All items are still available from the main typing module.

  • bpo-43633: Improve the textual representation of IPv4-mapped IPv6 addresses (RFC 4291 Sections 2.2, 2.5.5.2) in ipaddress. Patch by Oleksandr Pavliuk.

  • bpo-44850: Improve performance of operator.methodcaller() using the PEP 590 vectorcall convention. Patch by Anthony Lee and Pieter Eendebak.

  • bpo-44185: unittest.mock.mock_open() will call the close() method of the file handle mock when it is exiting from the context manager. Patch by Samet Yaslan.

  • bpo-40988: Improve performance of functools.singledispatchmethod by caching the generated dispatch wrapper. Optimization suggested by frederico. Patch by @mental32, Alex Waygood and Pieter Eendebak.

  • bpo-41768: unittest.mock speccing no longer calls class properties. Patch by Melanie Witt.

  • bpo-18319: Ensure gettext(msg) retrieve translations even if a plural form exists. In other words: gettext(msg) == ngettext(msg, '', 1).

  • bpo-17013: Add ThreadingMock to unittest.mock that can be used to create Mock objects that can wait until they are called. Patch by Karthikeyan Singaravelan and Mario Corchero.

Documentation

Tests

  • gh-110647: Fix test_stress_modifying_handlers() of test_signal. Patch by Victor Stinner.

  • gh-103053: Fix test_tools.test_freeze on FreeBSD: run "make distclean" instead of "make clean" in the copied source directory to remove also the "哋它亢" program. Patch by Victor Stinner.

  • gh-110167: Fix a deadlock in test_socket when server fails with a timeout but the client is still running in its thread. Don't hold a lock to call cleanup functions in doCleanups(). One of the cleanup function waits until the client completes, whereas the client could deadlock if it called addCleanup() in such situation. Patch by Victor Stinner.

  • gh-110388: Add tests for tty.

  • gh-81002: Add tests for termios.

  • gh-110367: regrtest: When using worker processes (-jN) with --verbose3 option, regrtest can now display the worker output even if a worker process does crash. Previously, sys.stdout and sys.stderr were replaced and so the worker output was lost on a crash. Patch by Victor Stinner.

  • gh-110267: Add tests for pickling and copying PyStructSequence objects. Patched by Xuehai Pan.

  • gh-110171: libregrtest now always sets and shows random.seed, so tests are more reproducible. Use --randseed flag to pass the explicit random seed for tests.

  • gh-110152: Remove Tools/scripts/run_tests.py and make hostrunnertest. Just run ./哋它亢 -m test --slow-ci, make buildbottest or make test instead. 哋它亢 test runner (regrtest) now handles cross-compilation and HOSTRUNNER. It also adds options to 哋它亢 such fast -u -E -W default -bb when --fast-ci or --slow-ci option is used. Patch by Victor Stinner.

  • gh-110031: Skip test_threading tests using thread+fork if 哋它亢 is built with Address Sanitizer (ASAN). Patch by Victor Stinner.

  • gh-110088: Fix test_asyncio timeouts: don't measure the maximum duration, a test should not measure a CI performance. Only measure the minimum duration when a task has a timeout or delay. Add CLOCK_RES to test_asyncio.utils. Patch by Victor Stinner.

  • gh-109974: Fix race conditions in test_threading lock tests. Wait until a condition is met rather than using time.sleep() with a hardcoded number of seconds. Patch by Victor Stinner.

  • gh-110033: Fix test_interprocess_signal() of test_signal. Make sure that the subprocess.Popen object is deleted before the test raising an exception in a signal handler. Otherwise, Popen.__del__() can get the exception which is logged as Exception ignored in: ... and the test fails. Patch by Victor Stinner.

  • gh-109594: Fix test_timeout() of test_concurrent_futures.test_wait. Remove the future which may or may not complete depending if it takes longer than the timeout or not. Keep the second future which does not complete before wait() timeout. Patch by Victor Stinner.

  • gh-109972: Split test_gdb.py file into a test_gdb package made of multiple tests, so tests can now be run in parallel. Patch by Victor Stinner.

  • gh-109566: regrtest: When --fast-ci or --slow-ci option is used, regrtest now replaces the current process with a new process to add -u -W default -bb -E options to 哋它亢. Patch by Victor Stinner.

  • gh-109748: Fix test_zippath_from_non_installed_posix() of test_venv: don't copy __pycache__/ sub-directories, because they can be modified by other 哋它亢 tests running in parallel. Patch by Victor Stinner.

  • gh-109739: regrtest: Fix reference leak check on Windows. Disable the load tracker on Windows in the reference leak check mode (-R option). Patch by Victor Stinner.

  • gh-109276: regrtest: When a test fails with "env changed" and the --rerun option is used, the test is now re-run in verbose mode in a fresh process. Patch by Victor Stinner.

  • gh-103053: Skip test_freeze_simple_script() of test_tools.test_freeze if 哋它亢 is built with ./configure --enable-optimizations, which means with Profile Guided Optimization (PGO): it just makes the test too slow. The freeze tool is tested by many other CIs with other (faster) compiler flags. Patch by Victor Stinner.

  • gh-109580: Skip test_perf_profiler if 哋它亢 is built with ASAN, MSAN or UBSAN sanitizer. 哋它亢 does crash randomly in this test on such build. Patch by Victor Stinner.

  • gh-109566: regrtest: Add --fast-ci and --slow-ci options. --fast-ci uses a default timeout of 10 minutes and -u all,-cpu (skip slowest tests). --slow-ci uses a default timeout of 20 minutes and -u all (run all tests). Patch by Victor Stinner.

  • gh-109425: libregrtest now decodes stdout of test worker processes with the "backslashreplace" error handler to log corrupted stdout, instead of failing with an error and not logging the stdout. Patch by Victor Stinner.

  • gh-109396: Fix test_socket.test_hmac_sha1() in FIPS mode. Use a longer key: FIPS mode requires at least of at least 112 bits. The previous key was only 32 bits. Patch by Victor Stinner.

  • gh-104736: Fix test_gdb on 哋它亢 built with LLVM clang 16 on Linux ppc64le (ex: Fedora 38). Search patterns in gdb "bt" command output to detect when gdb fails to retrieve the traceback. For example, skip a test if Backtrace stopped: frame did not save the PC is found. Patch by Victor Stinner.

  • gh-109276: libregrtest now calls random.seed() before running each test file when -r/--randomize command line option is used. Moreover, it's also called in worker processes. It should help to make tests more deterministic. Previously, it was only called once in the main process before running all test files and it was not called in worker processes. Patch by Victor Stinner.

  • gh-109276: libregrtest now uses a separated file descriptor to write test result as JSON. Previously, if a test wrote debug messages late around the JSON, the main test process failed to parse JSON. Patch by Victor Stinner.

  • gh-108996: Fix and enable test_msvcrt.

  • gh-109237: Fix test_site.test_underpth_basic() when the working directory contains at least one non-ASCII character: encode the ._pth file to UTF-8 and enable the UTF-8 Mode to use UTF-8 for the child process stdout. Patch by Victor Stinner.

  • gh-109230: Fix test_pyexpat.test_exception(): it can now be run from a directory different than 哋它亢 source code directory. Before, the test failed in this case. Skip the test if Modules/pyexpat.c source is not available. Skip also the test on 哋它亢 implementations other than C哋它亢. Patch by Victor Stinner.

  • gh-108996: Add tests for msvcrt.

  • gh-109015: Fix test_asyncio, test_imaplib and test_socket tests on FreeBSD if the TCP blackhole is enabled (sysctl net.inet.tcp.blackhole). Skip the few tests which failed with ETIMEDOUT which such non standard configuration. Currently, the FreeBSD GCP image enables TCP and UDP blackhole (sysctl net.inet.tcp.blackhole=2 and sysctl net.inet.udp.blackhole=1). Patch by Victor Stinner.

  • gh-91960: Skip test_gdb if gdb is unable to retrieve 哋它亢 frame objects: if a frame is <optimized out>. When 哋它亢 is built with "clang -Og", gdb can fail to retrieve the frame parameter of _PyEval_EvalFrameDefault(). In this case, tests like py_bt() are likely to fail. Without getting access to 哋它亢 frames, 哋它亢-gdb.py is mostly clueless on retrieving the 哋它亢 traceback. Moreover, test_gdb is no longer skipped on macOS if 哋它亢 is built with Clang. Patch by Victor Stinner.

  • gh-108962: Skip test_tempfile.test_flags() if chflags() fails with "OSError: [Errno 45] Operation not supported" (ex: on FreeBSD 13). Patch by Victor Stinner.

  • gh-91960: FreeBSD 13.2 CI coverage for pull requests is now provided by Cirrus-CI (a hosted CI service that supports Linux, macOS, Windows, and FreeBSD).

  • gh-89392: Removed support of test_main() function in tests. They now always use normal unittest test runner.

  • gh-108851: Fix test_tomllib recursion tests for WASI buildbots: reduce the recursion limit and compute the maximum nested array/dict depending on the current available recursion limit. Patch by Victor Stinner.

  • gh-108851: Add get_recursion_available() and get_recursion_depth() functions to the test.support module. Patch by Victor Stinner.

  • gh-108834: Add --fail-rerun option option to regrtest: if a test failed when then passed when rerun in verbose mode, exit the process with exit code 2 (error), instead of exit code 0 (success). Patch by Victor Stinner.

  • gh-108834: Rename regrtest --verbose2 option (-w) to --rerun. Keep --verbose2 as a deprecated alias. Patch by Victor Stinner.

  • gh-108834: When regrtest reruns failed tests in verbose mode (./哋它亢 -m test --rerun), tests are now rerun in fresh worker processes rather than being executed in the main process. If a test does crash or is killed by a timeout, the main process can detect and handle the killed worker process. Tests are rerun in parallel if the -jN option is used to run tests in parallel. Patch by Victor Stinner.

  • gh-108822: regrtest now computes statistics on all tests: successes, failures and skipped. test_netrc, test_pep646_syntax and test_xml_etree now return results in their test_main() function. Patch by Victor Stinner and Alex Waygood.

  • gh-108794: The doctest.DocTestRunner.run() method now counts the number of skipped tests. Add doctest.DocTestRunner.skips and doctest.TestResults.skipped attributes. Patch by Victor Stinner.

  • gh-108388: Convert test_concurrent_futures to a package of 7 sub-tests. Patch by Victor Stinner.

  • gh-108388: Split test_multiprocessing_fork, test_multiprocessing_forkserver and test_multiprocessing_spawn into test packages. Each package is made of 4 sub-tests: processes, threads, manager and misc. It allows running more tests in parallel and so reduce the total test duration. Patch by Victor Stinner.

  • gh-105776: Fix test_cppext when the C compiler command -std=c11 option: remove -std= options from the compiler command. Patch by Victor Stinner.

  • gh-107652: Set up CIFuzz to run fuzz targets in GitHub Actions. Patch by Illia Volochii.

  • gh-107237: test_logging: Fix test_udp_reconnection() by increasing the timeout from 100 ms to 5 minutes (LONG_TIMEOUT). Patch by Victor Stinner.

  • gh-107178: Add the C API test for functions in the Mapping Protocol, the Sequence Protocol and some functions in the Object Protocol.

  • gh-106714: test_capi: Fix test_no_FatalError_infinite_loop() to no longer write a coredump, by using test.support.SuppressCrashReport. Patch by Victor Stinner.

  • gh-104090: Avoid creating a reference to the test object in collectedDurations().

  • gh-106752: Moved tests for zipfile.Path into Lib/test/test_zipfile/_path. Made zipfile._path a package.

  • gh-106690: Add .coveragerc to c哋它亢 repository for use with coverage package.

  • gh-101634: When running the 哋它亢 test suite with -jN option, if a worker stdout cannot be decoded from the locale encoding report a failed testn so the exitcode is non-zero. Patch by Victor Stinner.

  • gh-105084: When the 哋它亢 build is configured --with-wheel-pkg-dir, tests requiring the setuptools and wheel wheels will search for the wheels in WHEEL_PKG_DIR.

  • gh-81005: String tests are modified to reflect that str and unicode are merged in 哋它亢 3. Patch by Daniel Fortunov.

  • gh-103186: Suppress and assert expected RuntimeWarnings in test_sys_settrace.py

  • gh-69714: Add additional tests to calendar to achieve full test coverage.

Build

  • gh-103053: "make check-clean-src" now also checks if the "哋它亢" program is found in the source directory: fail with an error if it does exist. Patch by Victor Stinner.

  • gh-109191: Fix compile error when building with recent versions of libedit.

  • gh-110276: No longer ignore PROFILE_TASK failure silently: command used by Profile Guided Optimization (PGO). Patch by Victor Stinner.

  • gh-109566: Remove make testall target: use make buildbottest instead. Patch by Victor Stinner.

  • gh-109740: The experimental --disable-gil configure flag now includes "t" (for "threaded") in extension ABI tags.

  • gh-109054: Fix building the _testcapi extension on Linux AArch64 which requires linking to libatomic when <c哋它亢/pyatomic.h> is used: the _Py_atomic_or_uint64() function requires libatomic __atomic_fetch_or_8() on this platform. The configure script now checks if linking to libatomic is needed and generates a new LIBATOMIC variable used to build the _testcapi extension. Patch by Victor Stinner.

  • gh-63760: Fix Solaris build: no longer redefine the gethostname() function. Solaris defines the function since 2005. Patch by Victor Stinner, original patch by Jakub Kulík.

  • gh-108740: Fix a race condition in make regen-all. The deepfreeze.c source and files generated by Argument Clinic are now generated or updated before generating "global objects". Previously, some identifiers may miss depending on the order in which these files were generated. Patch by Victor Stinner.

  • gh-108634: 哋它亢 built with configure --with-trace-refs (tracing references) is now ABI compatible with 哋它亢 release build and debug build. Patch by Victor Stinner.

  • gh-85283: The _stat C extension is now built with the limited C API. Patch by Victor Stinner.

  • gh-108447: Fix x86_64 GNU/Hurd build

  • gh-107814: When calling find_哋它亢.bat with -q it did not properly silence the output of nuget. That is now fixed.

  • gh-105481: Remove the make target regen-opcode-targets, merge its work into regen-opcode which repeats most of the calculation. This simplifies the code for the build and reduces code duplication.

  • gh-106881: Check for linux/limits.h before including it in Modules/posixmodule.c.

  • gh-95855: Refactor platform triplet detection code and add detection for MIPS soft float and musl libc.

  • gh-106962: Detect MPI compilers in configure.

  • gh-106118: Fix compilation for platforms without O_CLOEXEC. The issue was introduced with 哋它亢 3.12b1 in gh-103295. Patch by Erlend Aasland.

  • gh-105875: SQLite 3.15.2 or newer is required to build the sqlite3 extension module. Patch by Erlend Aasland.

  • gh-90005: Fix a regression in configure where we could end up unintentionally linking with libbsd.

  • gh-102404: Document how to perform a WASI build on Linux. Also add Tools/wasm/build_wasi.sh as a reference implementation of the docs.

  • gh-89886: Autoconf 2.71 and aclocal 1.16.4 is now required to regenerate !configure.

  • gh-104692: Include commoninstall as a prerequisite for bininstall

    This ensures that commoninstall is completed before bininstall is started when parallel builds are used (make -j install), and so the 哋它亢3 symlink is only installed after all standard library modules are installed.

  • gh-101538: Add experimental wasi-threads support. Patch by Takashi Yamamoto.

Windows

  • gh-110437: Allows overriding the source of VC redistributables so that releases can be guaranteed to never downgrade between updates.

  • gh-109286: Update Windows installer to use SQLite 3.43.1.

  • gh-82367: os.path.realpath() now resolves MS-DOS style file names even if the file is not accessible. Patch by Moonsik Park.

  • gh-109991: Update Windows build to use OpenSSL 3.0.11.

  • gh-106242: Fixes realpath() to behave consistently when passed a path containing an embedded null character on Windows. In strict mode, it now raises OSError instead of the unexpected ValueError, and in non-strict mode will make the path absolute.

  • gh-83180: Changes the 适用于Windows的哋它亢启动器 to prefer an active virtual environment when the launched script has a shebang line using a Unix-like virtual command, even if the command requests a specific version of 哋它亢.

  • gh-106844: Fix integer overflow and truncating by the null character in _winapi.LCMapStringEx() which affects ntpath.normcase().

  • gh-105436: Ensure that an empty environment block is terminated by two null characters, as is required by Windows.

  • gh-105146: Updated the links at the end of the installer to point to Discourse rather than the mailing lists.

  • gh-103646: When installed from the Microsoft Store, pip no longer defaults to per-user installs. However, as the install directory is unwritable, it should automatically decide to do a per-user install anyway. This should resolve issues when pip is passed an option that conflicts with --user.

  • gh-88745: Improve performance of shutil.copy2() by using the operating system's CopyFile2 function. This may result in subtle changes to metadata copied along with some files, bringing them in line with normal OS behavior.

  • gh-104820: Fixes stat() and related functions on file systems that do not support file ID requests. This includes FAT32 and exFAT.

  • gh-104803: Add os.path.isdevdrive() to detect whether a path is on a Windows Dev Drive. Returns False on platforms that do not support Dev Drive, and is absent on non-Windows platforms.

macOS

  • gh-109286: Update macOS installer to use SQLite 3.43.1.

  • gh-109991: Update macOS installer to use OpenSSL 3.0.11.

  • gh-99079: Update macOS installer to use OpenSSL 3.0.9.

IDLE

  • gh-104719: Remove IDLE's modification of tokenize.tabsize and test other uses of tokenize data and methods.

Tools/Demos

  • gh-109991: Update GitHub CI workflows to use OpenSSL 3.0.11 and multissltests to use 1.1.1w, 3.0.11, and 3.1.3.

  • gh-108494: Argument Clinic now has a partial support of the Limited API: see documentation in the 哋它亢 Developer's Guide Patch by Victor Stinner.

  • gh-107704: It is now possible to deprecate passing keyword arguments for keyword-or-positional parameters with Argument Clinic, using the new / [from X.Y] syntax. (To be read as "positional-only from 哋它亢 version X.Y".) See documentation in the 哋它亢 Developer's Guide for more information.

  • gh-107880: Argument Clinic can now clone __init__() and __new__() methods.

  • gh-104683: Add --exclude option to Argument Clinic CLI.

  • gh-95065: Argument Clinic now supports overriding automatically generated signature by using directive @text_signature. See documentation in the 哋它亢 Developer's Guide

  • gh-107609: Fix duplicate module check in Argument Clinic. Previously, a duplicate definition would incorrectly be silently accepted. Patch by Erlend E. Aasland.

  • gh-107467: The Argument Clinic command-line tool now prints to stderr instead of stdout on failure.

  • gh-106970: Fix bugs in the Argument Clinic destination <name> clear command; the destination buffers would never be cleared, and the destination directive parser would simply continue to the fault handler after processing the command. Patch by Erlend E. Aasland.

  • gh-106706: Change bytecode syntax for families to remove redundant name matching pseudo syntax.

  • gh-106359: Argument Clinic now explicitly forbids "kwarg splats" in function calls used as annotations.

  • gh-103186: freeze now fetches CONFIG_ARGS from the original C哋它亢 instance the Makefile uses to call utility scripts. Patch by Ijtaba Hussain.

  • gh-95065: It is now possible to deprecate passing parameters positionally with Argument Clinic, using the new * [from X.Y] syntax. (To be read as "keyword-only from 哋它亢 version X.Y".) See documentation in the 哋它亢 Developer's Guide for more information. Patch by Erlend E. Aasland with help from Alex Waygood, Nikita Sobolev, and Serhiy Storchaka.

C API

哋它亢 3.12.0 beta 1

Release date: 2023-05-22

Security

  • gh-99889: Fixed a security in flaw in uu.decode() that could allow for directory traversal based on the input if no out_file was specified.

  • gh-104049: Do not expose the local on-disk location in directory indexes produced by http.client.SimpleHTTPRequestHandler.

  • gh-99108: Upgrade built-in hashlib SHA3 implementation to a verified implementation from the HACL* project. Used when OpenSSL is not present or lacks SHA3.

  • gh-102153: urllib.parse.urlsplit() now strips leading C0 control and space characters following the specification for URLs defined by WHATWG in response to CVE 2023-24329. Patch by Illia Volochii.

Core and Builtins

  • gh-102856: Implement PEP 701 changes in the tokenize module. Patch by Marta Gómez Macías and Pablo Galindo Salgado

  • gh-104615: Fix wrong ordering of assignments in code like a, a = x, y. Contributed by Carl Meyer.

  • gh-104572: Improve syntax error message for invalid constructs in PEP 695 contexts and in annotations when from __future__ import annotations is active.

  • gh-104482: Fix three error handling bugs in ast.c's validation of pattern matching statements.

  • gh-102818: Do not add a frame to the traceback in the sys.setprofile and sys.settrace trampoline functions. This ensures that frames are not duplicated if an exception is raised in the callback function, and ensures that frames are not omitted if a C callback is used and that does not add the frame.

  • gh-104405: Fix an issue where some bytecode instructions could ignore PEP 523 when "inlining" calls.

  • gh-103082: Change behavior of sys.monitoring.events.LINE events in sys.monitoring: Line events now occur when a new line is reached dynamically, instead of using a static approximation, as before. This makes the behavior very similar to that of "line" events in sys.settrace. This should ease porting of tools from 3.11 to 3.12.

  • gh-104263: Fix float("nan") to produce a quiet NaN on platforms (like MIPS) where the meaning of the signalling / quiet bit is inverted from its usual meaning. Also introduce a new macro Py_INFINITY matching C99's INFINITY, and refactor internals to rely on C99's NAN and INFINITY macros instead of hard-coding bit patterns for infinities and NaNs. Thanks Sebastian Berg.

  • gh-99113: Multi-phase init extension modules may now indicate that they support running in subinterpreters that have their own GIL. This is done by using Py_MOD_PER_INTERPRETER_GIL_SUPPORTED as the value for the Py_mod_multiple_interpreters module def slot. Otherwise the module, by default, cannot be imported in such subinterpreters. (This does not affect the main interpreter or subinterpreters that do not have their own GIL.) In addition to the isolation that multi-phase init already normally requires, support for per-interpreter GIL involves one additional constraint: thread-safety. If the module has external (linked) dependencies and those libraries have any state that isn't thread-safe then the module must do the additional work to add thread-safety. This should be an uncommon case.

  • gh-99113: The GIL is now (optionally) per-interpreter. This is the fundamental change for PEP 684. This is all made possible by virtue of the isolated state of each interpreter in the process. The behavior of the main interpreter remains unchanged. Likewise, interpreters created using Py_NewInterpreter() are not affected. To get an interpreter with its own GIL, call Py_NewInterpreterFromConfig().

  • gh-104108: Multi-phase init extension modules may now indicate whether or not they actually support multiple interpreters. By default such modules are expected to support use in multiple interpreters. In the uncommon case that one does not, it may use the new Py_mod_multiple_interpreters module def slot. A value of 0 means the module does not support them. 1 means it does. The default is 1.

  • gh-104142: Fix an issue where list or tuple repetition could fail to respect PEP 683.

  • gh-104078: Improve the performance of PyObject_HasAttrString()

  • gh-104066: Improve the performance of hasattr() for module objects with a missing attribute.

  • gh-104028: Reduce object creation while calling callback function from gc. Patch by Donghee Na.

  • gh-104018: Disallow the "z" format specifier in %-format of bytes objects.

  • gh-102213: Fix performance loss when accessing an object's attributes with __getattr__ defined.

  • gh-103895: Improve handling of edge cases in showing Exception.__notes__. Ensures that the messages always end with a newline and that string/bytes are not exploded over multiple lines. Patch by Carey Metcalfe.

  • gh-103907: Don't modify the refcounts of known immortal objects (True, False, and None) in the main interpreter loop.

  • gh-103899: Provide a helpful hint in the TypeError message when accidentally calling a module object that has a callable attribute of the same name (such as dis.dis() or datetime.datetime).

  • gh-103845: Remove both line and instruction instrumentation before adding new ones for monitoring, to avoid newly added instrumentation being removed immediately.

  • gh-103763: Implement PEP 695, adding syntactic support for generic classes, generic functions, and type aliases.

    A new type X = ... syntax is added for type aliases, which resolves at runtime to an instance of the new class typing.TypeAliasType. The value is lazily evaluated and is accessible through the .__value__ attribute. This is implemented as a new AST node ast.TypeAlias.

    New syntax (class X[T]: ..., def func[T](): ...) is added for defining generic functions and classes. This is implemented as a new type_params attribute on the AST nodes for classes and functions. This node holds instances of the new AST classes ast.TypeVar, ast.ParamSpec, and ast.TypeVarTuple.

    typing.TypeVar, typing.ParamSpec, typing.ParamSpecArgs, typing.ParamSpecKwargs, typing.TypeVarTuple, and typing.Generic are now implemented in C rather than 哋它亢.

    There are new bytecode instructions LOAD_LOCALS, LOAD_CLASSDICT_OR_GLOBAL, and LOAD_CLASSDICT_OR_DEREF to support correct resolution of names in class namespaces.

    Patch by Eric Traut, Larry Hastings, and Jelle Zijlstra.

  • gh-103801: Adds three minor linting fixes to the wasm module caught that were caught by ruff.

  • gh-103793: Optimized asyncio Task creation by deferring expensive string formatting (task name generation) from Task creation to the first time get_name is called. This makes asyncio benchmarks up to 5% faster.

  • gh-102310: Change the error range for invalid bytes literals.

  • gh-103590: Do not wrap a single exception raised from a try-except* construct in an ExceptionGroup.

  • gh-103650: Change the perf map format to remove the '0x' prefix from the addresses

  • gh-102856: Implement the required C tokenizer changes for PEP 701. Patch by Pablo Galindo Salgado, Lysandros Nikolaou, Batuhan Taskaya, Marta Gómez Macías and sunmy2019.

  • gh-100530: Clarify the error message raised when the called part of a class pattern isn't actually a class.

  • gh-101517: Fix bug in line numbers of instructions emitted for except*.

  • gh-103492: Clarify SyntaxWarning with literal is comparison by specifying which literal is problematic, since comparisons using is with e.g. None and bool literals are idiomatic.

  • gh-87729: Add LOAD_SUPER_ATTR (and a specialization for super().method()) to speed up super().method() and super().attr. This makes super().method() roughly 2.3x faster and brings it within 20% of the performance of a simple method call. Patch by Vladimir Matveev and Carl Meyer.

  • gh-103488: Change the internal offset distinguishing yield and return target addresses, so that the instruction pointer is correct for exception handling and other stack unwinding.

  • gh-82012: The bitwise inversion operator (~) on bool is deprecated. It returns the bitwise inversion of the underlying int representation such that bool(~True) == True, which can be confusing. Use not for logical negation of bools. In the rare case that you really need the bitwise inversion of the underlying int, convert to int explicitly ~int(x).

  • gh-77757: Exceptions raised in a typeobject's __set_name__ method are no longer wrapped by a RuntimeError. Context information is added to the exception as a PEP 678 note.

  • gh-103333: AttributeError now retains the name attribute when pickled and unpickled.

  • gh-103242: Migrate set_ecdh_curve() method not to use deprecated OpenSSL APIs. Patch by Donghee Na.

  • gh-103323: We've replaced our use of _PyRuntime.tstate_current with a thread-local variable. This is a fairly low-level implementation detail, and there should be no change in behavior.

  • gh-84436: The implementation of PEP-683 which adds Immortal Objects by using a fixed reference count that skips reference counting to make objects truly immutable.

  • gh-102700: Allow built-in modules to be submodules. This allows submodules to be statically linked into a C哋它亢 binary.

  • gh-103082: Implement PEP 669 Low Impact Monitoring for C哋它亢.

  • gh-88691: Reduce the number of inline CACHE entries for CALL.

  • gh-102500: Make the buffer protocol accessible in 哋它亢 code using the new __buffer__ and __release_buffer__ magic methods. See PEP 688 for details. Patch by Jelle Zijlstra.

  • gh-97933: PEP 709: inline list, dict and set comprehensions to improve performance and reduce bytecode size.

  • gh-99184: Bypass instance attribute access of __name__ in repr of weakref.ref.

  • gh-98003: Complex function calls are now faster and consume no C stack space.

  • bpo-39610: len() for 0-dimensional memoryview objects (such as memoryview(ctypes.c_uint8(42))) now raises a TypeError. Previously this returned 1, which was not consistent with mem_0d[0] raising an IndexError.

  • bpo-31821: Fix pause_reading() to work when called from connection_made() in asyncio.

Library

  • gh-104600: functools.update_wrapper() now sets the __type_params__ attribute (added by PEP 695).

  • gh-104340: When an asyncio pipe protocol loses its connection due to an error, and the caller doesn't await wait_closed() on the corresponding StreamWriter, don't log a warning about an exception that was never retrieved. After all, according to the StreamWriter.close() docs, the wait_closed() call is optional ("not mandatory").

  • gh-104555: Fix issue where an issubclass() check comparing a class X against a runtime-checkable protocol Y with non-callable members would not cause TypeError to be raised if an isinstance() call had previously been made comparing an instance of X to Y. This issue was present in edge cases on 哋它亢 3.11, but became more prominent in 3.12 due to some unrelated changes that were made to runtime-checkable protocols. Patch by Alex Waygood.

  • gh-104372: Refactored the _posixsubprocess internals to avoid 哋它亢 C API usage between fork and exec when marking pass_fds= file descriptors inheritable.

  • gh-104484: Added case_sensitive argument to pathlib.PurePath.match()

  • gh-75367: Fix data descriptor detection in inspect.getattr_static().

  • gh-104536: Fix a race condition in the internal multiprocessing.process cleanup logic that could manifest as an unintended AttributeError when calling process.close().

  • gh-103857: Update datetime deprecations' stracktrace to point to the calling line

  • gh-101520: Move the core functionality of the tracemalloc module in the 哋它亢/ folder, leaving just the module wrapper in Modules/.

  • gh-104392: Remove undocumented and unused _paramspec_tvars attribute from some classes in typing.

  • gh-102613: Fix issue where pathlib.Path.glob() raised RecursionError when walking deep directory trees.

  • gh-103000: Improve performance of dataclasses.asdict() for the common case where dict_factory is dict. Patch by David C Ellis.

  • gh-104301: Allow leading whitespace in disambiguated statements in pdb.

  • gh-104139: Teach urllib.parse.unsplit() to retain the "//" when assembling itms-services://?action=generate-bugs style Apple Platform Deployment URLs.

  • gh-104307: socket.getnameinfo() now releases the GIL while contacting the DNS server

  • gh-104310: Users may now use importlib.util.allowing_all_extensions() (a context manager) to temporarily disable the strict compatibility checks for importing extension modules in subinterpreters.

  • gh-87695: Fix issue where pathlib.Path.glob() raised OSError when it encountered a symlink to an overly long path.

  • gh-104265: Prevent possible crash by disallowing instantiation of the _csv.Reader and _csv.Writer types. The regression was introduced in 3.10.0a4 with PR 23224 (bpo-14935). Patch by Radislav Chugunov.

  • gh-102613: Improve performance of pathlib.Path.glob() when expanding recursive wildcards ("**") by merging adjacent wildcards and de-duplicating results only when necessary.

  • gh-65772: Remove unneeded comments and code in turtle.py.

  • gh-90208: Fixed issue where pathlib.Path.glob() returned incomplete results when it encountered a PermissionError. This method now suppresses all OSError exceptions, except those raised from calling is_dir() on the top-level path.

  • gh-104144: Optimize asyncio.TaskGroup when using asyncio.eager_task_factory(). Skip scheduling a done callback if a TaskGroup task completes eagerly.

  • gh-104144: Optimize asyncio.gather() when using asyncio.eager_task_factory() to complete eagerly if all fututres completed eagerly. Avoid scheduling done callbacks for futures that complete eagerly.

  • gh-104114: Fix issue where pathlib.Path.glob() returns paths using the case of non-wildcard segments for corresponding path segments, rather than the real filesystem case.

  • gh-104104: Improve performance of pathlib.Path.glob() by using re.IGNORECASE to implement case-insensitive matching.

  • gh-104102: Improve performance of pathlib.Path.glob() when evaluating patterns that contain '../' segments.

  • gh-103822: Update the return type of weekday to the newly added Day attribute

  • gh-103629: Update the repr of typing.Unpack according to PEP 692.

  • gh-103963: Make dis display the names of the args for CALL_INTRINSIC_*.

  • gh-104035: Do not ignore user-defined __getstate__ and __setstate__ methods for slotted frozen dataclasses.

  • gh-103987: In mmap, fix several bugs that could lead to access to memory-mapped files after they have been invalidated.

  • gh-103977: Improve import time of platform module.

  • gh-88773: Added turtle.teleport() to the turtle module to move a turtle to a new point without tracing a line, visible or invisible. Patch by Liam Gersten.

  • gh-103935: Use io.open_code() for files to be executed instead of raw open()

  • gh-68968: Fixed garbled output of assertEqual() when an input lacks final newline.

  • gh-100370: Fix potential OverflowError in sqlite3.Connection.blobopen() for 32-bit builds. Patch by Erlend E. Aasland.

  • gh-102628: Substitute CTRL-D with CTRL-Z in sqlite3 CLI banner when running on Windows.

  • gh-103636: Module-level attributes January and February are deprecated from calendar.

  • gh-103583: Isolate _multibytecodec and codecs extension modules. Patches by Erlend E. Aasland.

  • gh-103848: Add checks to ensure that [ bracketed ] hosts found by urllib.parse.urlsplit() are of IPv6 or IPvFuture format.

  • gh-103872: Update the bundled copy of pip to version 23.1.2.

  • gh-99944: Make dis display the value of oparg of KW_NAMES.

  • gh-74940: The C.UTF-8 locale is no longer converted to en_US.UTF-8, enabling the use of UTF-8 encoding on systems which have no locales installed.

  • gh-103861: Fix zipfile.Zipfile creating invalid zip files when force_zip64 was used to add files to them. Patch by Carey Metcalfe.

  • gh-103857: Deprecated datetime.datetime.utcnow() and datetime.datetime.utcfromtimestamp(). (Patch by Paul Ganssle)

  • gh-103839: Avoid compilation error due to tommath.h not being found when building Tkinter against Tcl 8.7 built with bundled libtommath.

  • gh-103791: contextlib.suppress now supports suppressing exceptions raised as part of an ExceptionGroup. If other exceptions exist on the group, they are re-raised in a group that does not contain the suppressed exceptions.

  • gh-90750: Use datetime.datetime.fromisocalendar() in the implementation of datetime.datetime.strptime(), which should now accept only valid ISO dates. (Patch by Paul Ganssle)

  • gh-103685: Prepare tkinter.Menu.index() for Tk 8.7 so that it does not raise TclError: expected integer but got "" when it should return None.

  • gh-81403: urllib.request.CacheFTPHandler no longer raises URLError if a cached FTP instance is reused. ftplib's endtransfer method calls voidresp to drain the connection to handle FTP instance reuse properly.

  • gh-103699: Add __orig_bases__ to non-generic TypedDicts, call-based TypedDicts, and call-based NamedTuples. Other TypedDicts and NamedTuples already had the attribute.

  • gh-103693: Add convenience variable feature to pdb

  • gh-92248: Deprecate type, choices, and metavar parameters of argparse.BooleanOptionalAction.

  • gh-89415: Add socket constants for source-specific multicast. Patch by Reese Hyde.

  • gh-103673: socketserver gains ForkingUnixStreamServer and ForkingUnixDatagramServer classes. Patch by Jay Berry.

  • gh-103636: Added Enum for months and days in the calendar module.

  • gh-84976: Create a new Lib/_pydatetime.py file that defines the 哋它亢 version of the datetime module, and make datetime import the contents of the new library only if the C implementation is missing. Currently, the full 哋它亢 implementation is defined and then deleted if the C implementation is not available, slowing down import datetime unnecessarily.

  • gh-103596: Attributes/methods are no longer shadowed by same-named enum members, although they may be shadowed by enum.property's.

  • gh-103584: Updated importlib.metadata with changes from importlib_metadata 5.2 through 6.5.0, including: Support installed-files.txt for Distribution.files when present. PackageMetadata now stipulates an additional get method allowing for easy querying of metadata keys that may not be present. packages_distributions now honors packages and modules with 哋它亢 modules that not .py sources (e.g. .pyc, .so). Expand protocol for PackageMetadata.get_all to match the upstream implementation of email.message.Message.get_all in 哋它亢/typeshed#9620. Deprecated use of Distribution without defining abstract methods. Deprecated expectation that PackageMetadata.__getitem__ will return None for missing keys. In the future, it will raise a KeyError.

  • gh-103578: Fixed a bug where pdb crashes when reading source file with different encoding by replacing io.open() with io.open_code(). The new method would also call into the hook set by PyFile_SetOpenCodeHook().

  • gh-103556: Now creating inspect.Signature objects with positional-only parameter with a default followed by a positional-or-keyword parameter without one is impossible.

  • gh-103559: Update the bundled copy of pip to version 23.1.1.

  • gh-103548: Improve performance of pathlib.Path.absolute() and cwd() by joining paths only when necessary. Also improve performance of pathlib.PurePath.is_absolute() on Posix by skipping path parsing and normalization.

  • gh-103538: Remove _tkinter module code guarded by definition of the TK_AQUA macro which was only needed for Tk 8.4.7 or earlier and was never actually defined by any build system or documented for manual use.

  • gh-103533: Update cProfile to use PEP 669 API

  • gh-103525: Fix misleading exception message when mixed str and bytes arguments are supplied to pathlib.PurePath and Path.

  • gh-103489: Add getconfig() and setconfig() to Connection to make configuration changes to a database connection. Patch by Erlend E. Aasland.

  • gh-103365: Set default Flag boundary to STRICT and fix bitwise operations.

  • gh-103472: Avoid a potential ResourceWarning in http.client.HTTPConnection by closing the proxy / tunnel's CONNECT response explicitly.

  • gh-103462: Fixed an issue with using writelines() in asyncio to send very large payloads that exceed the amount of data that can be written in one call to socket.socket.send() or socket.socket.sendmsg(), resulting in the remaining buffer being left unwritten.

  • gh-103449: Fix a bug in doc string generation in dataclasses.dataclass().

  • gh-103092: Isolate _collections (apply PEP 687). Patch by Erlend E. Aasland.

  • gh-103357: Added support for logging.Formatter defaults parameter to logging.config.dictConfig() and logging.config.fileConfig(). Patch by Bar Harel.

  • gh-103092: Adapt the winreg extension module to PEP 687.

  • gh-74690: The performance of isinstance() checks against runtime-checkable protocols has been considerably improved for protocols that only have a few members. To achieve this improvement, several internal implementation details of the typing module have been refactored, including typing._ProtocolMeta.__instancecheck__, typing._is_callable_members_only, and typing._get_protocol_attrs. Patches by Alex Waygood.

  • gh-74690: The members of a runtime-checkable protocol are now considered "frozen" at runtime as soon as the class has been created. See "What's new in 哋它亢 3.12" for more details.

  • gh-103256: Fixed a bug that caused hmac to raise an exception when the requested hash algorithm was not available in OpenSSL despite being available separately as part of hashlib itself. It now falls back properly to the built-in. This could happen when, for example, your OpenSSL does not include SHA3 support and you want to compute hmac.digest(b'K', b'M', 'sha3_256').

  • gh-102778: Support sys.last_exc in idlelib.

  • gh-103285: Improve performance of ast.get_source_segment().

  • gh-103225: Fix a bug in pdb when displaying line numbers of module-level source code.

  • gh-103092: Adapt the msvcrt extension module to PEP 687.

  • gh-103092: Adapt the winsound extension module to PEP 687.

  • gh-93910: Remove deprecation of enum member.member access.

  • gh-102978: Fixes unittest.mock.patch() not enforcing function signatures for methods decorated with @classmethod or @staticmethod when patch is called with autospec=True.

  • gh-103092: Isolate _socket (apply PEP 687). Patch by Erlend E. Aasland.

  • gh-100479: Add pathlib.PurePath.with_segments(), which creates a path object from arguments. This method is called whenever a derivative path is created, such as from pathlib.PurePath.parent. Subclasses may override this method to share information between path objects.

  • gh-103220: Fix issue where os.path.join() added a slash when joining onto an incomplete UNC drive with a trailing slash on Windows.

  • gh-103204: Fixes http.server accepting HTTP requests with HTTP version numbers preceded by '+', or '-', or with digit-separating '_' characters. The length of the version numbers is also constrained.

  • gh-75586: Fix various Windows-specific issues with shutil.which.

  • gh-103193: Improve performance of inspect.getattr_static(). Patch by Alex Waygood.

  • gh-103176: sys._current_exceptions() now returns a mapping from thread-id to an exception instance, rather than to a (typ, exc, tb) tuple.

  • gh-103143: Polish the help messages and docstrings of pdb.

  • gh-103015: Add entrypoint keyword-only parameter to sqlite3.Connection.load_extension(), for overriding the SQLite extension entry point. Patch by Erlend E. Aasland.

  • gh-103000: Improve performance of dataclasses.astuple() and dataclasses.asdict() in cases where the contents are common 哋它亢 types.

  • gh-102953: The extraction methods in tarfile, and shutil.unpack_archive(), have a new a filter argument that allows limiting tar features than may be surprising or dangerous, such as creating files outside the destination directory. See 解压缩过滤器 for details.

  • gh-97696: Implemented an eager task factory in asyncio. When used as a task factory on an event loop, it performs eager execution of coroutines. Coroutines that are able to complete synchronously (e.g. return or raise without blocking) are returned immediately as a finished task, and the task is never scheduled to the event loop. If the coroutine blocks, the (pending) task is scheduled and returned.

  • gh-81079: Add case_sensitive keyword-only argument to pathlib.Path.glob() and rglob().

  • gh-101819: Isolate the io extension module by applying PEP 687. Patch by Kumar Aditya, Victor Stinner, and Erlend E. Aasland.

  • gh-91896: Deprecate collections.abc.ByteString

  • gh-101362: Speed up pathlib.Path construction by omitting the path anchor from the internal list of path parts.

  • gh-102114: Functions in the dis module that accept a source code string as argument now print a more concise traceback when the string contains a syntax or indentation error.

  • gh-62432: The unittest runner will now exit with status code 5 if no tests were run. It is common for test runner misconfiguration to fail to find any tests, this should be an error.

  • gh-78079: Fix incorrect normalization of UNC device path roots, and partial UNC share path roots, in pathlib.PurePath. Pathlib no longer appends a trailing slash to such paths.

  • gh-85984: Add tty.cfmakeraw() and tty.cfmakecbreak() to tty and modernize, the behavior of tty.setraw() and tty.setcbreak() to use POSIX.1-2017 Chapter 11 "General Terminal Interface" flag masks by default.

  • gh-101688: Implement types.get_original_bases() to provide further introspection for types.

  • gh-101640: argparse.ArgumentParser now catches errors when writing messages, such as when sys.stderr is None. Patch by Oleg Iarygin.

  • gh-83861: Fix datetime.astimezone method return value when invoked on a naive datetime instance that represents local time falling in a timezone transition gap. PEP 495 requires that instances with fold=1 produce earlier times than those with fold=0 in this case.

  • gh-89550: Decrease execution time of some gzip file writes by 15% by adding more appropriate buffering.

  • gh-95299: Remove the bundled setuptools wheel from ensurepip, and stop installing setuptools in environments created by venv.

  • gh-99353: Respect the http.client.HTTPConnection .debuglevel flag in urllib.request.AbstractHTTPHandler when its constructor parameter debuglevel is not set. And do the same for *HTTPS*.

  • gh-98040: Remove the long-deprecated imp module.

  • gh-97850: Deprecate pkgutil.find_loader() and pkgutil.get_loader() in favor of importlib.util.find_spec().

  • gh-94473: Flatten arguments in tkinter.Canvas.coords(). It now accepts not only x1, y1, x2, y2, ... and [x1, y1, x2, y2, ...], but also (x1, y1), (x2, y2), ... and [(x1, y1), (x2, y2), ...].

  • gh-98040: Remove more deprecated importlib APIs: find_loader(), find_module(), importlib.abc.Finder, pkgutil.ImpImporter, pkgutil.ImpLoader.

  • gh-96522: Fix potential deadlock in pty.spawn()

  • gh-96534: Support divert(4) added in FreeBSD 14.

  • gh-87474: Fix potential file descriptor leaks in subprocess.Popen.

  • gh-94906: Support multiple steps in math.nextafter(). Patch by Shantanu Jain and Matthias Gorgens.

  • gh-51574: Make tempfile.mkdtemp() return absolute paths when its dir parameter is relative.

  • gh-94518: Convert private _posixsubprocess.fork_exec() to use Argument Clinic.

  • gh-92184: When creating zip files using zipfile, os.altsep, if not None, will always be treated as a path separator even when it is not /. Patch by Carey Metcalfe.

  • bpo-46797: Deprecation warnings are now emitted for ast.Num, ast.Bytes, ast.Str, ast.NameConstant and ast.Ellipsis. These have been documented as deprecated since 哋它亢 3.8, and will be removed in 哋它亢 3.14.

  • bpo-44844: Enables webbrowser to detect and launch Microsoft Edge browser.

  • bpo-45606: Fixed the bug in pathlib.Path.glob() -- previously a dangling symlink would not be found by this method when the pattern is an exact match, but would be found when the pattern contains a wildcard or the recursive wildcard (**). With this change, a dangling symlink will be found in both cases.

  • bpo-23041: Add QUOTE_STRINGS and QUOTE_NOTNULL to the suite of csv module quoting styles.

  • bpo-24964: Added http.client.HTTPConnection.get_proxy_response_headers() that provides access to the HTTP headers on a proxy server response to the CONNECT request.

  • bpo-17258: multiprocessing now supports stronger HMAC algorithms for inter-process connection authentication rather than only HMAC-MD5.

  • bpo-39744: Make asyncio.subprocess.Process.communicate() close the subprocess's stdin even when called with input=None.

  • bpo-22708: http.client CONNECT method tunnel improvements: Use HTTP 1.1 protocol; send a matching Host: header with CONNECT, if one is not provided; convert IDN domain names to Punycode. Patch by Michael Handler.

Documentation

  • gh-67056: Document that the effect of registering or unregistering an atexit cleanup function from within a registered cleanup function is undefined.

  • gh-103629: Mention the new way of typing **kwargs with Unpack and TypedDict introduced in PEP 692.

  • gh-48241: Clarifying documentation about the url parameter to urllib.request.urlopen and urllib.request.Request needing to be encoded properly.

  • gh-86094: Add support for Unicode Path Extra Field in ZipFile. Patch by Yeojin Kim and Andrea Giudiceandrea

  • gh-99202: Fix extension type from documentation for compiling in C++20 mode

Tests

  • gh-104494: Update test_pack_configure_in and test_place_configure_in for changes to error message formatting in Tk 8.7.

  • gh-104461: Run test_configure_screen on X11 only, since the DISPLAY environment variable and -screen option for toplevels are not useful on Tk for Win32 or Aqua.

  • gh-86275: Added property-based tests to the zoneinfo tests, along with stubs for the hypothesis interface. (Patch by Paul Ganssle)

  • gh-103329: Regression tests for the behaviour of unittest.mock.PropertyMock were added.

  • gh-102795: fix use of poll in test_epoll's test_control_and_wait

  • gh-75729: Fix the os.spawn* tests failing on Windows when the working directory or interpreter path contains spaces.

Build

  • gh-101282: BOLT optimization is now applied to the lib哋它亢 shared library if building a shared library. BOLT instrumentation and application settings can now be influenced via the BOLT_INSTRUMENT_FLAGS and BOLT_APPLY_FLAGS configure variables.

  • gh-99017: 哋它亢_FOR_REGEN now require 哋它亢 3.10 or newer.

  • gh-104490: Define .PHONY / virtual make targets consistently and properly.

  • gh-104106: Add gcc fallback of mkfifoat/mknodat for macOS. Patch by Donghee Na.

  • gh-103532: The TKINTER_PROTECT_LOADTK macro is no longer defined or used in the _tkinter module. It was previously only defined when building against Tk 8.4.13 and older, but Tk older than 8.5.12 has been unsupported since gh-91152.

  • gh-99069: Extended workaround defining static_assert when missing from the libc headers to all clang and gcc builds. In particular, this fixes building on macOS <= 10.10.

  • gh-100220: Changed the default value of the SHELL Makefile variable from /bin/sh to /bin/sh -e to ensure that complex recipes correctly fail after an error. Previously, make install could fail to install some files and yet return a successful result.

  • gh-90656: Add platform triplets for 64-bit LoongArch:

    • loongarch64-linux-gnusf

    • loongarch64-linux-gnuf32

    • loongarch64-linux-gnu

    Patch by Zhang Na.

Windows

  • gh-104623: Update Windows installer to use SQLite 3.42.0.

  • gh-82814: Fix a potential [Errno 13] Permission denied when using shutil.copystat() within Windows Subsystem for Linux (WSL) on a mounted filesystem by adding errno.EACCES to the list of ignored errors within the internal implementation.

  • gh-103088: Fix virtual environment activate script having incorrect line endings for Cygwin.

  • gh-103088: Fixes venvs not working in bash on Windows across different disks

  • gh-102997: Update Windows installer to use SQLite 3.41.2.

  • gh-88013: Fixed a bug where TypeError was raised when calling ntpath.realpath() with a bytes parameter in some cases.

macOS

  • gh-99834: Update macOS installer to Tcl/Tk 8.6.13.

  • gh-104623: Update macOS installer to SQLite 3.42.0.

  • gh-103545: Add os.PRIO_DARWIN_THREAD, os.PRIO_DARWIN_PROCESS, os.PRIO_DARWIN_BG and os.PRIO_DARWIN_NONUI. These can be used with os.setpriority to run the process at a lower priority and make use of the efficiency cores on Apple Silicon systems.

  • gh-104180: Support reading SOCKS proxy configuration from macOS System Configuration. Patch by Sam Schott.

  • gh-60436: update curses textbox to additionally handle backspace using the curses.ascii.DEL key press.

  • gh-102997: Update macOS installer to SQLite 3.41.2.

IDLE

  • gh-104499: Fix completions for Tk Aqua 8.7 (currently blank).

  • gh-104496: About prints both tcl and tk versions if different (expected someday).

  • gh-88496: Fix IDLE test hang on macOS.

Tools/Demos

  • gh-104389: Argument Clinic C converters now accept the unused keyword, for wrapping a parameter with Py_UNUSED. Patch by Erlend E. Aasland.

C API

哋它亢 3.12.0 alpha 7

Release date: 2023-04-04

Core and Builtins

  • gh-102192: Deprecated _PyErr_ChainExceptions in favour of _PyErr_ChainExceptions1.

  • gh-89987: Reduce the number of inline CACHE entries for BINARY_SUBSCR.

  • gh-102859: Removed JUMP_IF_FALSE_OR_POP and JUMP_IF_TRUE_OR_POP instructions.

  • gh-101975: Fixed stacktop value on tracing entries to avoid corruption on garbage collection.

  • gh-102778: Add sys.last_exc and deprecate sys.last_type, sys.last_value and sys.last_traceback, which hold the same information in its legacy form.

  • gh-100982: Replace all occurrences of COMPARE_AND_BRANCH with COMPARE_OP.

  • gh-102701: Fix overflow when creating very large dict.

  • gh-102755: Add PyErr_DisplayException() which takes just an exception instance, to replace the legacy PyErr_Display() which takes the (typ, exc, tb) triplet.

  • gh-102594: Add note to exception raised in PyErr_SetObject when normalization fails.

  • gh-90997: Shrink the number of inline CACHE entries used by LOAD_GLOBAL.

  • gh-102491: Improve import time of platform by removing Iron哋它亢 version parsing. The Iron哋它亢 version parsing was not functional (see https://github.com/IronLanguages/iron哋它亢3/issues/1667).

  • gh-101291: Rearrage bits in first field (after header) of PyLongObject. * Bits 0 and 1: 1 - sign. I.e. 0 for positive numbers, 1 for zero and 2 for negative numbers. * Bit 2 reserved (probably for the immortal bit) * Bits 3+ the unsigned size.

    This makes a few operations slightly more efficient, and will enable a more compact and faster 2s-complement representation of most ints in future.

  • gh-102397: Fix segfault from race condition in signal handling during garbage collection. Patch by Kumar Aditya.

  • gh-102406: codecs encoding/decoding errors now get the context information (which operation and which codecs) attached as PEP 678 notes instead of through chaining a new instance of the exception.

  • gh-102281: Fix potential nullptr dereference and use of uninitialized memory in fileutils. Patch by Max Bachmann.

  • gh-102300: Reuse operands with refcount of 1 in float specializations of BINARY_OP.

  • gh-102213: Fix performance loss when accessing an object's attributes with __getattr__ defined.

  • gh-102255: Improve build support for the Xbox. Patch by Max Bachmann.

  • gh-102027: Fix SSE2 and SSE3 detection in _blake2 internal module. Patch by Max Bachmann.

  • gh-101865: Deprecate co_lnotab in code objects, schedule it for removal in 哋它亢 3.14

  • bpo-1635741: Adapt _pickle to PEP 687. Patch by Mohamed Koubaa and Erlend Aasland.

Library

Documentation

Tests

  • gh-102980: Improve test coverage on pdb.

  • gh-102537: Adjust the error handling strategy in test_zoneinfo.TzPathTest.哋它亢_tzpath_context. Patch by Paul Ganssle.

  • gh-101377: Improved test_locale_calendar_formatweekday of calendar.

Build

  • gh-102973: Add a dev container (along with accompanying Dockerfile) for development purposes.

  • gh-102711: Fix -Wstrict-prototypes compiler warnings.

Windows

  • gh-102690: Update webbrowser to fall back to Microsoft Edge instead of Internet Explorer.

  • gh-99726: Improves correctness of stat results for Windows, and uses faster API when available

Tools/Demos

C API

  • gh-102013: Add a new (unstable) C-API function for iterating over GC'able objects using a callback: PyUnstable_VisitObjects.

哋它亢 3.12.0 alpha 6

Release date: 2023-03-07

Security

  • gh-99108: Replace builtin hashlib implementations of MD5 and SHA1 with verified ones from the HACL* project.

  • gh-101727: Updated the OpenSSL version used in Windows and macOS binary release builds to 1.1.1t to address CVE 2023-0286, CVE 2022-4303, and CVE 2022-4303 per the OpenSSL 2023-02-07 security advisory.

  • gh-99108: Replace the builtin hashlib implementations of SHA2-384 and SHA2-512 originally from LibTomCrypt with formally verified, side-channel resistant code from the HACL* project. The builtins remain a fallback only used when OpenSSL does not provide them.

  • gh-101283: subprocess.Popen now uses a safer approach to find cmd.exe when launching with shell=True. Patch by Eryk Sun, based on a patch by Oleg Iarygin.

Core and Builtins

  • gh-102493: Fix regression in semantics of normalisation in PyErr_SetObject.

  • gh-102416: Do not memoize incorrectly automatically generated loop rules in the parser. Patch by Pablo Galindo.

  • gh-102356: Fix a bug that caused a crash when deallocating deeply nested filter objects. Patch by Marta Gómez Macías.

  • gh-102336: Cleanup Windows 7 specific special handling. Patch by Max Bachmann.

  • gh-102250: Fixed a segfault occurring when the interpreter calls a __bool__ method that raises.

  • gh-102126: Fix deadlock at shutdown when clearing thread states if any finalizer tries to acquire the runtime head lock. Patch by Kumar Aditya.

  • gh-102027: Use GetCurrentProcessId on Windows when getpid is unavailable. Patch by Max Bachmann.

  • gh-102056: Fix error handling bugs in interpreter's exception printing code, which could cause a crash on infinite recursion.

  • gh-100982: Restrict the scope of the FOR_ITER_RANGE instruction to the scope of the original FOR_ITER instruction, to allow instrumentation.

  • gh-101967: Fix possible segfault in positional_only_passed_as_keyword function, when new list created.

  • gh-101952: Fix possible segfault in BUILD_SET opcode, when new set created.

  • gh-74895: socket.getaddrinfo no longer raises OverflowError for int port values outside of the C long range. Out of range values are left up to the underlying string based C library API to report. A socket.gaierror SAI_SERVICE may occur instead, or no error at all as not all platform C libraries generate an error.

  • gh-101799: Add CALL_INTRINSIC_2 and use it instead of PREP_RERAISE_STAR.

  • gh-101857: Fix xattr support detection on Linux systems by widening the check to linux, not just glibc. This fixes support for musl.

  • gh-84783: Make the slice object hashable. Patch by Will Bradshaw and Furkan Onder.

  • gh-87849: Change the SEND instruction to leave the receiver on the stack. This allows the specialized form of SEND to skip the chain of C calls and jump directly to the RESUME in the generator or coroutine.

  • gh-101765: Fix SystemError / segmentation fault in iter __reduce__ when internal access of builtins.__dict__ keys mutates the iter object.

  • gh-101430: Update tracemalloc to handle presize of object properly. Patch by Donghee Na.

  • gh-101696: Invalidate type version tag in _PyStaticType_Dealloc for static types, avoiding bug where a false cache hit could crash the interpreter. Patch by Kumar Aditya.

  • gh-101632: Adds a new RETURN_CONST instruction.

  • gh-100719: Remove gi_code field from generator (and coroutine and async generator) objects as it is redundant. The frame already includes a reference to the code object.

  • gh-98627: When an interpreter is configured to check (and only then), importing an extension module will now fail when the extension does not support multiple interpreters (i.e. doesn't implement PEP 489 multi-phase init). This does not apply to the main interpreter, nor to subinterpreters created with Py_NewInterpreter().

Library

Documentation

Tests

  • gh-102019: Fix deadlock on shutdown if test_current_{exception,frames} fails. Patch by Jacob Bower.

  • gh-85984: Utilize new "winsize" functions from termios in pty tests.

  • gh-89792: test_tools now copies up to 10x less source data to a temporary directory during the freeze test by ignoring git metadata and other artifacts. It also limits its 哋它亢 build parallelism based on os.cpu_count instead of hard coding it as 8 cores.

Build

  • gh-99942: On Android, in a static build, 哋它亢-config in embed mode no longer incorrectly reports a library to link to.

  • gh-99942: On Android, 哋它亢.pc now correctly reports the library to link to, the same as 哋它亢-config.sh.

  • gh-100221: Fix creating install directories in make sharedinstall if they exist outside DESTDIR already.

  • gh-96821: Explicitly mark C extension modules that need defined signed integer overflow, and add a configure option --with-strict-overflow. Patch by Matthias Görgens and Shantanu Jain.

Windows

  • gh-102344: Implement winreg.QueryValue using QueryValueEx and winreg.SetValue using SetValueEx. Patch by Max Bachmann.

  • gh-101881: Handle read and write operations on non-blocking pipes properly on Windows.

  • gh-101881: Add support for the os.get_blocking() and os.set_blocking() functions on Windows.

  • gh-101849: Ensures installer will correctly upgrade existing py.exe launcher installs.

  • gh-101763: Updates copy of libffi bundled with Windows installs to 3.4.4.

  • gh-101759: Update Windows installer to SQLite 3.40.1.

  • gh-101614: Correctly handle extensions built against debug binaries that reference 哋它亢3_d.dll.

  • gh-101196: The functions os.path.isdir, os.path.isfile, os.path.islink and os.path.exists are now 13% to 28% faster on Windows, by making fewer Win32 API calls.

macOS

  • gh-101759: Update macOS installer to SQLite 3.40.1.

C API

哋它亢 3.12.0 alpha 5

Release date: 2023-02-07

Security

  • gh-99108: Replace the builtin hashlib implementations of SHA2-224 and SHA2-256 originally from LibTomCrypt with formally verified, side-channel resistant code from the HACL* project. The builtins remain a fallback only used when OpenSSL does not provide them.

Core and Builtins

  • gh-92173: Fix the defs and kwdefs arguments to PyEval_EvalCodeEx() and a reference leak in that function.

  • gh-59956: The GILState API is now partially compatible with subinterpreters. Previously, PyThreadState_GET() and PyGILState_GetThisThreadState() would get out of sync, causing inconsistent behavior and crashes.

  • gh-101400: Fix wrong lineno in exception message on continue or break which are not in a loop. Patch by Donghee Na.

  • gh-101372: Fix is_normalized() to properly handle the UCD 3.2.0 cases. Patch by Donghee Na.

  • gh-101266: Fix sys.getsizeof() reporting for int subclasses.

  • gh-101291: Refactor the PyLongObject struct into a normal 哋它亢 object header and a PyLongValue struct.

  • gh-101046: Fix a possible memory leak in the parser when raising MemoryError. Patch by Pablo Galindo

  • gh-101037: Fix potential memory underallocation issue for instances of int subclasses with value zero.

  • gh-100762: Record the (virtual) exception block depth in the oparg of YIELD_VALUE. Use this to avoid the expensive throw() when closing generators (and coroutines) that can be closed trivially.

  • gh-100982: Adds a new COMPARE_AND_BRANCH instruction. This is a bit more efficient when performing a comparison immediately followed by a branch, and restores the design intent of PEP 659 that specializations are local to a single instruction.

  • gh-100942: Fixed segfault in property.getter/setter/deleter that occurred when a property subclass overrode the __new__ method to return a non-property instance.

  • gh-100923: Remove the mask cache entry for the COMPARE_OP instruction and embed the mask into the oparg.

  • gh-100892: Fix race while iterating over thread states in clearing threading.local. Patch by Kumar Aditya.

  • gh-91351: Fix a case where re-entrant imports could corrupt the import deadlock detection code and cause a KeyError to be raised out of importlib/_bootstrap. In addition to the straightforward cases, this could also happen when garbage collection leads to a warning being emitted -- as happens when it collects an open socket or file)

  • gh-100726: Optimize construction of range object for medium size integers.

  • gh-100712: Added option to build c哋它亢 with specialization disabled, by setting ENABLE_SPECIALIZATION=False in opcode, followed by make regen-all.

  • bpo-32780: Inter-field padding is now inserted into the PEP3118 format strings obtained from ctypes.Structure objects, reflecting their true representation in memory.

Library

  • gh-101541: [Enum] - fix psuedo-flag creation

  • gh-101570: Upgrade pip wheel bundled with ensurepip (pip 23.0)

  • gh-101323: Fix a bug where errors where not thrown by zlib._ZlibDecompressor if encountered during decompressing.

  • gh-101317: Add ssl_shutdown_timeout parameter for asyncio.StreamWriter.start_tls().

  • gh-101326: Fix regression when passing None as second or third argument to FutureIter.throw.

  • gh-92123: Adapt the _elementtree extension module to multi-phase init (PEP 489). Patches by Erlend E. Aasland.

  • gh-100795: Avoid potential unexpected freeaddrinfo call (double free) in socket when when a libc getaddrinfo() implementation leaves garbage in an output pointer when returning an error. Original patch by Sergey G. Brester.

  • gh-101143: Remove unused references to TimerHandle in asyncio.base_events.BaseEventLoop._add_callback.

  • gh-101144: Make zipfile.Path.open() and zipfile.Path.read_text() also accept encoding as a positional argument. This was the behavior in 哋它亢 3.9 and earlier. 3.10 introduced a regression where supplying it as a positional argument would lead to a TypeError.

  • gh-94518: Group-related variables of _posixsubprocess module are renamed to stress that supplementary group affinity is added to a fork, not replace the inherited ones. Patch by Oleg Iarygin.

  • gh-101015: Fix typing.get_type_hints() on '*tuple[...]' and *tuple[...]. It must not drop the Unpack part.

  • gh-101000: Add os.path.splitroot(), which splits a path into a 3-item tuple (drive, root, tail). This new function is used by pathlib to improve the performance of path construction by up to a third.

  • gh-100573: Fix a Windows asyncio bug with named pipes where a client doing os.stat() on the pipe would cause an error in the server that disabled serving future requests.

  • gh-39615: warnings.warn() now has the ability to skip stack frames based on code filename prefix rather than only a numeric stacklevel via the new skip_file_prefixes keyword argument.

  • gh-100750: pass encoding kwarg to subprocess in platform

  • gh-100160: Emit a deprecation warning in asyncio.DefaultEventLoopPolicy.get_event_loop() if there is no current event loop set and it decides to create one.

  • gh-96290: Fix handling of partial and invalid UNC drives in ntpath.splitdrive(), and in ntpath.normpath() on non-Windows systems. Paths such as '\server' and '\' are now considered by splitdrive() to contain only a drive, and consequently are not modified by normpath() on non-Windows systems. The behaviour of normpath() on Windows systems is unaffected, as native OS APIs are used. Patch by Eryk Sun, with contributions by Barney Gale.

  • gh-99952: Fix a reference undercounting issue in ctypes.Structure with from_param() results larger than a C pointer.

  • gh-67790: Add float-style formatting support for fractions.Fraction instances.

  • gh-99266: Preserve more detailed error messages in ctypes.

  • gh-86682: Ensure runtime-created collections have the correct module name using the newly added (internal) sys._getframemodulename().

  • gh-88597: uuid now has a command line interface. Try 哋它亢 -m uuid -h.

  • gh-60580: ctypes.wintypes.BYTE definition changed from c_byte to c_ubyte to match Windows SDK. Patch by Anatoly Techtonik and Oleg Iarygin.

  • gh-94518: _posixsubprocess now initializes all UID and GID variables using a reserved -1 value instead of a separate flag. Patch by Oleg Iarygin.

  • bpo-38941: The xml.etree.ElementTree module now emits DeprecationWarning when testing the truth value of an xml.etree.ElementTree.Element. Before, the 哋它亢 implementation emitted FutureWarning, and the C implementation emitted nothing.

  • bpo-40077: Convert elementtree types to heap types. Patch by Erlend E. Aasland.

  • bpo-29847: Fix a bug where pathlib.Path accepted and ignored keyword arguments. Patch provided by Yurii Karabas.

  • gh-77772: ctypes.CDLL, ctypes.OleDLL, ctypes.WinDLL, and ctypes.PyDLL now accept path-like objects as their name argument. Patch by Robert Hoelzl.

Documentation

  • gh-88324: Reword subprocess to emphasize default behavior of stdin, stdout, and stderr arguments. Remove inaccurate statement about child file handle inheritance.

Tests

  • gh-101334: test_tarfile has been updated to pass when run as a high UID.

Build

  • gh-101282: Update BOLT configuration not to use deprecated usage of --split functions. Patch by Donghee Na.

  • gh-101522: Allow overriding Windows dependencies versions and paths using MSBuild properties.

  • gh-77532: Minor fixes to allow building with PlatformToolset=ClangCL on Windows.

  • gh-101152: In accordance with PEP 699, the ma_version_tag field in PyDictObject is deprecated for extension modules. Accessing this field will generate a compiler warning at compile time. This field will be removed in 哋它亢 3.14.

  • gh-100340: Allows -Wno-int-conversion for wasm-sdk 17 and onwards, thus enables building WASI builds once against the latest sdk.

  • gh-101060: Conditionally add -fno-reorder-blocks-and-partition in configure. Effectively fixes --enable-bolt when using Clang, as this appears to be a GCC-only flag.

  • gh-98705: __bool__ is defined in AIX system header files which breaks the build in AIX, so undefine it.

  • gh-98636: Fix a regression in detecting gdbm_compat library for the _gdbm module build.

  • gh-96305: _aix_support now uses a simple code to get platform details rather than the now non-existent _bootsubprocess during bootstrap.

Windows

  • gh-101543: Ensure the install path in the registry is only used when the standard library hasn't been located in any other way.

  • gh-101467: The py.exe launcher now correctly filters when only a single runtime is installed. It also correctly handles prefix matches on tags so that -3.1 does not match 3.11, but would still match 3.1-32.

  • gh-99834: Updates bundled copy of Tcl/Tk to 8.6.13.0

  • gh-101135: Restore ability to launch older 32-bit versions from the py.exe launcher when both 32-bit and 64-bit installs of the same version are available.

  • gh-82052: Fixed an issue where writing more than 32K of Unicode output to the console screen in one go can result in mojibake.

  • gh-100320: Ensures the 哋它亢Path registry key from an install is used when launching from a different copy of 哋它亢 that relies on an existing install to provide a copy of its modules and standard library.

  • gh-100247: Restores support for the py.exe launcher finding shebang commands in its configuration file using the full command name.

哋它亢 3.12.0 alpha 4

Release date: 2023-01-10

Core and Builtins

  • gh-100776: Fix misleading default value in input()'s __text_signature__.

  • gh-99005: Remove UNARY_POSITIVE, ASYNC_GEN_WRAP and LIST_TO_TUPLE, replacing them with intrinsics.

  • gh-99005: Add new CALL_INTRINSIC_1 instruction. Remove IMPORT_STAR, PRINT_EXPR and STOPITERATION_ERROR, replacing them with the CALL_INTRINSIC_1 instruction.

  • gh-100288: Remove the LOAD_ATTR_METHOD_WITH_DICT specialized instruction. Stats show it is not useful.

  • gh-100720: Added _PyFrame_NumSlotsForCodeObject, which returns the number of slots needed in a frame for a given code object.

  • gh-100719: Removed the co_nplaincellvars field from the code object, as it is redundant.

  • gh-100637: Fix int.__sizeof__() calculation to include the 1-element ob_digit array for 0 and False.

  • gh-100649: Update the native_thread_id field of PyThreadState after fork.

  • gh-100126: Fix an issue where "incomplete" frames could be briefly visible to C code while other frames are being torn down, possibly resulting in corruption or hard crashes of the interpreter while running finalizers.

  • gh-87447: Fix SyntaxError on comprehension rebind checking with names that are not actually redefined.

    Now reassigning b in [(b := 1) for a, b.prop in some_iter] is allowed. Reassigning a is still disallowed as per PEP 572.

  • gh-100268: Add int.is_integer() to improve duck type compatibility between int and float.

  • gh-100425: Improve the accuracy of sum() with compensated summation.

  • gh-100374: Fix incorrect result and delay in socket.getfqdn(). Patch by Dominic Socular.

  • gh-100357: Convert vars, dir, next, getattr, and iter to argument clinic.

  • gh-100117: Improve the output of codeobject.co_lines() by emitting only one entry for each line range.

  • gh-90043: Handle NaNs when specializing COMPARE_OP for float values.

  • gh-100222: Redefine the _Py_CODEUNIT typedef as a union to describe its layout to the C compiler, avoiding type punning and improving clarity.

  • gh-99955: Internal compiler functions (in compile.c) now consistently return -1 on error and 0 on success.

  • gh-100188: The BINARY_SUBSCR_LIST_INT and BINARY_SUBSCR_TUPLE_INT instructions are no longer used for negative integers because those instructions always miss when encountering negative integers.

  • gh-99110: Initialize frame->previous in frameobject.c to fix a segmentation fault when accessing frames created by PyFrame_New().

  • gh-94155: Improved the hashing algorithm for code objects, mitigating some hash collisions.

  • gh-99540: None now hashes to a constant value. This is not a requirements change.

  • gh-100143: When built with --enable-pystats, stats collection is now off by default. To enable it early at startup, pass the -Xpystats flag. Stats are now always dumped, even if switched off.

  • gh-100146: Improve BUILD_LIST opcode so that it works similarly to the BUILD_TUPLE opcode, by stealing references from the stack rather than repeatedly using stack operations to set list elements. Implementation details are in a new private API _PyList_FromArraySteal().

  • gh-100110: Specialize FOR_ITER for tuples.

  • gh-100050: Honor existing errors obtained when searching for mismatching parentheses in the tokenizer. Patch by Pablo Galindo

  • gh-92216: Improve the performance of hasattr() for type objects with a missing attribute.

  • gh-99582: Freeze zipimport module into _bootstrap_哋它亢.

  • gh-99554: Pack debugging location tables more efficiently during bytecode compilation.

  • gh-98522: Add an internal version number to code objects, to give better versioning of inner functions and comprehensions, and thus better specialization of those functions. This change is invisible to both 哋它亢 and C extensions.

  • gh-94603: Improve performance of list.pop for small lists.

  • gh-89051: Add ssl.OP_LEGACY_SERVER_CONNECT

  • bpo-32782: ctypes arrays of length 0 now report a correct itemsize when a memoryview is constructed from them, rather than always giving a value of 0.

Library

Documentation

Tests

  • gh-100454: Start running SSL tests with OpenSSL 3.1.0-beta1.

  • gh-100086: The 哋它亢 test runner (libregrtest) now logs 哋它亢 build information like "debug" vs "release" build, or LTO and PGO optimizations. Patch by Victor Stinner.

  • gh-93018: Make two tests forgiving towards host system libexpat with backported security fixes applied.

Build

  • gh-100540: Removed the --with-system-ffi configure option; libffi must now always be supplied by the system on all non-Windows platforms. The option has had no effect on non-Darwin platforms for several releases, and in 3.11 only had the non-obvious effect of invoking pkg-config to find libffi and never setting -DUSING_APPLE_OS_LIBFFI. Now on Darwin platforms configure will first check for the OS libffi and then fall back to the same processing as other platforms if it is not found.

  • gh-88267: Avoid exporting 哋它亢 symbols in linked Windows applications when the core is built as static.

  • bpo-41916: Allow override of ac_cv_cxx_thread so that cross compiled 哋它亢 can set -pthread for CXX.

Windows

  • gh-100180: Update Windows installer to OpenSSL 1.1.1s

  • gh-99191: Use _MSVC_LANG >= 202002L instead of less-precise _MSC_VER >=1929 to more accurately test for C++20 support in PC/_wmimodule.cpp.

  • gh-79218: Define MS_WIN64 for Mingw-w64 64bit, fix cython compilation failure.

  • gh-99941: Ensure that asyncio.Protocol.data_received() receives an immutable bytes object (as documented), instead of bytearray.

  • bpo-43984: winreg.SetValueEx() now leaves the target value untouched in the case of conversion errors. Previously, -1 would be written in case of such errors.

  • bpo-34816: hasattr(ctypes.windll, 'nonexistant') now returns False instead of raising OSError.

macOS

  • gh-100180: Update macOS installer to OpenSSL 1.1.1s

  • gh-100540: Removed obsolete dlfcn.h shim from the _ctypes extension module, which has not been necessary since Mac OS X 10.2.

Tools/Demos

  • bpo-45256: Fix a bug that caused an AttributeError to be raised in 哋它亢-gdb.py when py-locals is used without a frame.

  • gh-100342: Add missing NULL check for possible allocation failure in *args parsing in Argument Clinic.

C API

  • gh-99947: Raising SystemError on import will now have its cause be set to the original unexpected exception.

  • gh-99240: In argument parsing, after deallocating newly allocated memory, reset its pointer to NULL.

  • gh-98724: The Py_CLEAR, Py_SETREF and Py_XSETREF macros now only evaluate their arguments once. If an argument has side effects, these side effects are no longer duplicated. Patch by Victor Stinner.

哋它亢 3.12.0 alpha 3

Release date: 2022-12-06

Security

  • gh-100001: 哋它亢 -m http.server no longer allows terminal control characters sent within a garbage request to be printed to the stderr server log.

    This is done by changing the http.server BaseHTTPRequestHandler .log_message method to replace control characters with a \xHH hex escape before printing.

  • gh-87604: Avoid publishing list of active per-interpreter audit hooks via the gc module

Core and Builtins

  • gh-99891: Fix a bug in the tokenizer that could cause infinite recursion when showing syntax warnings that happen in the first line of the source. Patch by Pablo Galindo

  • gh-91054: Add PyCode_AddWatcher() and PyCode_ClearWatcher() APIs to register callbacks to receive notification on creation and destruction of code objects.

  • gh-99729: Fix an issue that could cause frames to be visible to 哋它亢 code as they are being torn down, possibly leading to memory corruption or hard crashes of the interpreter.

  • gh-99708: Fix bug where compiler crashes on an if expression with an empty body block.

  • gh-99578: Fix a reference bug in _imp.create_builtin() after the creation of the first sub-interpreter for modules builtins and sys. Patch by Victor Stinner.

  • gh-99581: Fixed a bug that was causing a buffer overflow if the tokenizer copies a line missing the newline character from a file that is as long as the available tokenizer buffer. Patch by Pablo galindo

  • gh-99553: Fix bug where an ExceptionGroup subclass can wrap a BaseException.

  • gh-99547: Add a function to os.path to check if a path is a junction: isjunction. Add similar functionality to pathlib.Path as is_junction.

  • gh-99370: Fix zip path for venv created from a non-installed 哋它亢 on POSIX platforms.

  • gh-99377: Add audit events for thread creation and clear operations.

  • gh-98686: Remove the BINARY_OP_GENERIC and COMPARE_OP_GENERIC "specializations".

  • gh-99298: Remove the remaining error paths for attribute specializations, and refuse to specialize attribute accesses on types that haven't had PyType_Ready() called on them yet.

  • gh-99127: Allow some features of syslog to the main interpreter only. Patch by Donghee Na.

  • gh-91053: Optimizing interpreters and JIT compilers may need to invalidate internal metadata when functions are modified. This change adds the ability to provide a callback that will be invoked each time a function is created, modified, or destroyed.

  • gh-90994: Improve error messages when there's a syntax error with call arguments. The following three cases are covered: - No value is assigned to a named argument, eg foo(a=). - A value is assigned to a star argument, eg foo(*args=[0]). - A value is assigned to a double-star keyword argument, eg foo(**kwarg={'a': 0}).

  • bpo-45026: Optimize the range object iterator. It is now smaller, faster iteration of ranges containing large numbers. Smaller pickles, faster unpickling.

  • bpo-31718: Raise ValueError instead of SystemError when methods of uninitialized io.IncrementalNewlineDecoder objects are called. Patch by Oren Milman.

  • bpo-38031: Fix a possible assertion failure in io.FileIO when the opener returns an invalid file descriptor.

Library

  • gh-100001: Also escape s in the http.server BaseHTTPRequestHandler.log_message so that it is technically possible to parse the line and reconstruct what the original data was. Without this a xHH is ambiguous as to if it is a hex replacement we put in or the characters r"x" came through in the original request line.

  • gh-99957: Add frozen_default parameter to typing.dataclass_transform().

  • gh-79033: Fix asyncio.Server.wait_closed() to actually do what the docs promise -- wait for all existing connections to complete, after closing the server.

  • gh-51524: Fix bug when calling trace.CoverageResults with valid infile.

  • gh-99645: Fix a bug in handling class cleanups in unittest.TestCase. Now addClassCleanup() uses separate lists for different TestCase subclasses, and doClassCleanups() only cleans up the particular class.

  • gh-99508: Fix TypeError in Lib/importlib/_bootstrap_external.py while calling _imp.source_hash().

  • gh-66285: Fix asyncio to not share event loop and signal wakeupfd in forked processes. Patch by Kumar Aditya.

  • gh-97001: Release the GIL when calling termios APIs to avoid blocking threads.

  • gh-92647: Use final status of an enum to determine lookup or creation branch of functional API.

  • gh-99388: Add loop_factory parameter to asyncio.run() to allow specifying a custom event loop factory. Patch by Kumar Aditya.

  • gh-99341: Fix ast.increment_lineno() to also cover ast.TypeIgnore when changing line numbers.

  • gh-99382: Check the number of arguments in substitution in user generics containing a TypeVarTuple and one or more TypeVar.

  • gh-99379: Fix substitution of ParamSpec followed by TypeVarTuple in generic aliases.

  • gh-99344: Fix substitution of TypeVarTuple and ParamSpec together in user generics.

  • gh-99284: Remove _use_broken_old_ctypes_structure_semantics_ old untested and undocumented hack from ctypes.

  • gh-99201: Fix IndexError when initializing the config variables on Windows if HAVE_DYNAMIC_LOADING is not set.

  • gh-99240: Fix double-free bug in Argument Clinic str_converter by extracting memory clean up to a new post_parsing section.

  • gh-64490: Fix refcount error when arguments are packed to tuple in Argument Clinic.

  • gh-99029: pathlib.PurePath.relative_to() now treats naked Windows drive paths as relative. This brings its behaviour in line with other parts of pathlib.

  • gh-98253: The implementation of the typing module is now more resilient to reference leaks in binary extension modules.

    Previously, a reference leak in a typed C API-based extension module could leak internals of the typing module, which could in turn introduce leaks in essentially any other package with typed function signatures. Although the typing package is not the original source of the problem, such non-local dependences exacerbate debugging of large-scale projects, and the implementation was therefore changed to reduce harm by providing better isolation.

  • gh-98458: Fix infinite loop in unittest when a self-referencing chained exception is raised

  • gh-93453: asyncio.get_event_loop() and many other asyncio functions like asyncio.ensure_future(), asyncio.shield() or asyncio.gather(), and also the get_event_loop() method of asyncio.BaseDefaultEventLoopPolicy now raise a RuntimeError if called when there is no running event loop and the current event loop was not set. Previously they implicitly created and set a new current event loop. DeprecationWarning is no longer emitted if there is no running event loop but the current event loop was set.

  • gh-97966: On uname_result, restored expectation that _fields and _asdict would include all six properties including processor.

  • gh-98248: Provide informative error messages in struct.pack() when its integral arguments are not in range.

  • gh-98108: zipfile.Path is now pickleable if its initialization parameters were pickleable (e.g. for file system paths).

  • gh-98098: Created packages from zipfile and test_zipfile modules, separating zipfile.Path functionality.

  • gh-82836: Fix is_private properties in the ipaddress module. Previously non-private networks (0.0.0.0/0) would return True from this method; now they correctly return False.

  • gh-96828: Add an OP_ENABLE_KTLS option for enabling the use of the kernel TLS (kTLS). Patch by Illia Volochii.

  • gh-88863: To avoid apparent memory leaks when asyncio.open_connection() raises, break reference cycles generated by local exception and future instances (which has exception instance as its member var). Patch by Dong Uk, Kang.

  • gh-91078: TarFile.next() now returns None when called on an empty tarfile.

  • bpo-47220: Document the optional callback parameter of WeakMethod. Patch by Géry Ogam.

  • bpo-44817: Ignore WinError 53 (ERROR_BAD_NETPATH), 65 (ERROR_NETWORK_ACCESS_DENIED) and 161 (ERROR_BAD_PATHNAME) when using ntpath.realpath().

  • bpo-41260: Rename the fmt parameter of the pure 哋它亢 implementation of datetime.date.strftime() to format.

  • bpo-15999: All built-in functions now accept arguments of any type instead of just bool and int for boolean parameters.

Documentation

  • gh-99931: Use sphinxext-opengraph to generate OpenGraph metadata.

  • gh-89682: Reworded docstring of the default __contains__ to clarify that it returns a bool.

  • gh-88330: Improved the description of what a resource is in importlib.resources docs.

  • gh-92892: Document that calling variadic functions with ctypes requires special care on macOS/arm64 (and possibly other platforms).

  • bpo-41825: Restructured the documentation for the os.wait* family of functions, and improved the docs for os.waitid() with more explanation of the possible argument constants.

Tests

  • gh-99892: Skip test_normalization() of test_unicodedata if it fails to download NormalizationTest.txt file from 哋它亢test.net. Patch by Victor Stinner.

  • gh-99934: Correct test_marsh on (32 bit) x86: test_deterministic sets was failing.

  • gh-99741: We've implemented multi-phase init (PEP 489/630/687) for the internal (for testing) _xxsubinterpreters module.

  • gh-99659: Optional big memory tests in test_sqlite3 now catch the correct sqlite.DataError exception type in case of too large strings and/or blobs passed.

  • gh-99593: Cover the Unicode C API with tests.

  • gh-96002: Add functional test for Argument Clinic.

Build

  • gh-99086: Fix -Wimplicit-int, -Wstrict-prototypes, and -Wimplicit-function-declaration compiler warnings in configure checks.

  • gh-99337: Fix a compilation issue with GCC 12 on macOS.

  • gh-99289: Add a COMPILEALL_OPTS variable in Makefile to override compileall options (default: -j0) in make install. Also merged the compileall commands into a single command building .pyc files for the all optimization levels (0, 1, 2) at once. Patch by Victor Stinner.

  • gh-98872: Fix a possible fd leak in Programs/_freeze_module.c introduced in 哋它亢 3.11.

  • gh-88226: Always define TARGET_* labels in 哋它亢/ceval.c, even if USE_COMPUTED_GOTOS is disabled. This allows breakpoints to be set at those labels in (for instance) gdb.

Windows

macOS

  • gh-87235: On macOS 哋它亢3 /dev/fd/9 9</path/to/script.py failed for any script longer than a couple of bytes.

  • gh-98940: Fix Mac/Extras.install.py file filter bug.

Tools/Demos

  • gh-64490: Argument Clinic varargs bugfixes

    • Fix out-of-bounds error in _PyArg_UnpackKeywordsWithVararg().

    • Fix incorrect check which allowed more than one varargs in clinic.py.

    • Fix miscalculation of noptargs in generated code.

    • Do not generate noptargs when there is a vararg argument and no optional argument.

C API

  • gh-98680: PyBUF_* constants were marked as part of Limited API of 哋它亢 3.11+. These were available in 3.11.0 with Py_LIMITED_API defined for 3.11, and are necessary to use the buffer API.

  • gh-99612: Fix PyUnicode_DecodeUTF8Stateful() for ASCII-only data: *consumed was not set.

  • gh-47146: The structmember.h header is deprecated. Its non-deprecated contents are now available just by including 哋它亢.h, with a Py_ prefix added if it was missing. (Deprecated contents are T_OBJECT, T_NONE, and no-op flags.) Patch by Petr Viktorin, based on earlier work by Alexander Belopolsky and Matthias Braun.

哋它亢 3.12.0 alpha 2

Release date: 2022-11-14

Security

  • gh-98433: The IDNA codec decoder used on DNS hostnames by socket or asyncio related name resolution functions no longer involves a quadratic algorithm. This prevents a potential CPU denial of service if an out-of-spec excessive length hostname involving bidirectional characters were decoded. Some protocols such as urllib http 3xx redirects potentially allow for an attacker to supply such a name.

    Individual labels within an IDNA encoded DNS name will now raise an error early during IDNA decoding if they are longer than 1024 unicode characters given that each decoded DNS label must be 63 or fewer characters and the entire decoded DNS name is limited to 255. Only an application presenting a hostname or label consisting primarily of RFC 3454 section 3.1 "Nothing" characters to be removed would run into of this new limit. See also RFC 5894 section 6 and RFC 3491.

  • gh-98739: Update bundled libexpat to 2.5.0

Core and Builtins

  • gh-81057: The docs clearly say that PyImport_Inittab, PyImport_AppendInittab(), and PyImport_ExtendInittab() should not be used after Py_Initialize() has been called. We now enforce this for the two functions. Additionally, the runtime now uses an internal copy of PyImport_Inittab, to guard against modification.

  • gh-99298: Fix an issue that could potentially cause incorrect error handling for some bytecode instructions.

  • gh-99254: The compiler now removes all unused constants from code objects (except the first one, which may be a docstring).

  • gh-99205: Fix an issue that prevented PyThreadState and PyInterpreterState memory from being freed properly.

  • gh-81057: The 18 global C variables holding the state of the allocators have been moved to _PyRuntimeState. This is a strictly internal change with no change in behavior.

  • gh-99181: Fix failure in except* with unhashable exceptions.

  • gh-99204: Fix calculation of sys._base_executable when inside a POSIX virtual environment using copies of the 哋它亢 binary when the base installation does not provide the executable name used by the venv. Calculation will fall back to alternative names ("哋它亢<MAJOR>", "哋它亢<MAJOR>.<MINOR>").

  • gh-96055: Update faulthandler to emit an error message with the proper unexpected signal number. Patch by Donghee Na.

  • gh-99153: Fix location of SyntaxError for a try block with both except and except*.

  • gh-98686: Merge the adaptive opcode logic into each instruction's unquickened variant, and merge the logic in EXTENDED_ARG_QUICK into EXTENDED_ARG. With these changes, the quickening that happens at code object creation is now only responsible for initializing warmup counters and inserting superinstructions.

  • gh-99103: Fix the error reporting positions of specialized traceback anchors when the source line contains Unicode characters.

  • gh-99139: Improve the error suggestion for NameError exceptions for instances. Now if a NameError is raised in a method and the instance has an attribute that's exactly equal to the name in the exception, the suggestion will include self.<NAME> instead of the closest match in the method scope. Patch by Pablo Galindo

  • gh-98401: Octal escapes with value larger than 0o377 (ex: "\477"), deprecated in 哋它亢 3.11, now produce a SyntaxWarning, instead of DeprecationWarning. In a future 哋它亢 version they will be eventually a SyntaxError. Patch by Victor Stinner.

  • gh-98401: A backslash-character pair that is not a valid escape sequence now generates a SyntaxWarning, instead of DeprecationWarning. For example, re.compile("\d+\.\d+") now emits a SyntaxWarning ("\d" is an invalid escape sequence), use raw strings for regular expression: re.compile(r"\d+\.\d+"). In a future 哋它亢 version, SyntaxError will eventually be raised, instead of SyntaxWarning. Patch by Victor Stinner.

  • gh-96793: Handle StopIteration and StopAsyncIteration raised in generator or coroutines in the bytecode, rather than in wrapping C code.

  • gh-98931: Improve the SyntaxError error message when the user types import x from y instead of from y import x. Patch by Pablo Galindo

  • gh-98852: Fix subscription of type aliases containing bare generic types or types like TypeVar: for example tuple[A, T][int] and tuple[TypeVar, T][int], where A is a generic type, and T is a type variable.

  • gh-98925: Lower the recursion depth for marshal on WASI to support (in-development) wasmtime 2.0.

  • gh-98783: Fix multiple crashes in debug mode when str subclasses are used instead of str itself.

  • gh-98811: Use complete source locations to simplify detection of __future__ imports which are not at the beginning of the file. Also corrects the offset in the exception raised in one case, which was off by one and impeded highlighting.

  • gh-96793: Add specialization of FOR_ITER for generators. Saves multiple layers of dispatch and checking to get from the FOR_ITER instruction in the caller to the RESUME in the generator.

  • gh-98762: Fix source locations of match sub-patterns.

  • gh-98586: Added the methods PyObject_Vectorcall() and PyObject_VectorcallMethod() to the Limited API along with the auxiliary macro constant PY_VECTORCALL_ARGUMENTS_OFFSET.

    The availability of these functions enables more efficient PEP 590 vector calls from binary extension modules that avoid argument boxing/unboxing overheads.

  • gh-99257: Fix an issue where member descriptors (such as those for __slots__) could behave incorrectly or crash instead of raising a TypeError when accessed via an instance of an invalid type.

  • gh-93143: Rather than changing co_code, the interpreter will now display a RuntimeWarning and assign None to any fast locals that are left unbound after jumps or del statements executed while tracing.

  • gh-96421: When calling into 哋它亢 code from C code, through PyEval_EvalFrameEx() or a related C-API function, a shim frame in inserted into the call stack. This occurs in the _PyEval_EvalFrameDefault() function. The extra frame should be invisible to all 哋它亢 and most C extensions, but out-of-process profilers and debuggers need to be aware of it. These shim frames can be detected by checking frame->owner == FRAME_OWNED_BY_CSTACK.

    Extensions implementing their own interpreters using PEP 523 need to be aware of this shim frame and the changes to the semantics of RETURN_VALUE, YIELD_VALUE, and RETURN_GENERATOR, which now clear the frame.

  • gh-98415: Fix detection of MAC addresses for uuid on certain OSs. Patch by Chaim Sanders

  • gh-98686: Quicken all code objects, and specialize adaptive bytecode instructions more aggressively.

  • gh-92119: Print exception class name instead of its string representation when raising errors from ctypes calls.

  • gh-91058: ImportError raised from failed from <module> import <name> now include suggestions for the value of <name> based on the available names in <module>. Patch by Pablo Galindo

  • gh-96793: The FOR_ITER now leaves the iterator on the stack on termination of the loop. This is to assist specialization of loops for generators.

  • gh-90716: Add _pylong.py module. It includes asymptotically faster algorithms that can be used for operations on integers with many digits. It is used by longobject.c to speed up some operations.

  • gh-95389: Expose ETH_P_ALL and some of the ETHERTYPE_* constants in socket. Patch by Noam Cohen.

  • gh-93696: Allow pdb to locate source for frozen modules in the standard library.

Library

  • gh-99418: Fix bug in urllib.parse.urlparse() that causes URL schemes that begin with a digit, a plus sign, or a minus sign to be parsed incorrectly.

  • gh-94597: Deprecate asyncio.AbstractChildWatcher to be removed in 哋它亢 3.14. Patch by Kumar Aditya.

  • gh-99305: Improve performance of secrets.token_hex().

  • gh-74044: Fixed bug where inspect.signature() reported incorrect arguments for decorated methods.

  • gh-99275: Fix SystemError in ctypes when exception was not set during __initsubclass__.

  • gh-99277: Remove older version of _SSLProtocolTransport.get_write_buffer_limits in asyncio.sslproto

  • gh-99248: fix negative numbers failing in verify()

  • gh-99155: Fix statistics.NormalDist pickle with 0 and 1 protocols.

  • gh-93464: enum.auto() is now correctly activated when combined with other assignment values. E.g. ONE = auto(), 'some text' will now evaluate as (1, 'some text').

  • gh-99134: Update the bundled copy of pip to version 22.3.1.

  • gh-92584: Remove the distutils package. It was deprecated in 哋它亢 3.10 by PEP 632 "Deprecate distutils module". For projects still using distutils and cannot be updated to something else, the setuptools project can be installed: it still provides distutils. Patch by Victor Stinner.

  • gh-98999: Now _pyio is consistent with _io in raising ValueError when executing methods over closed buffers.

  • gh-83004: Clean up refleak on failed module initialisation in _zoneinfo

  • gh-83004: Clean up refleaks on failed module initialisation in _pickle

  • gh-83004: Clean up refleak on failed module initialisation in _io.

  • gh-98897: Fix memory leak in math.dist() when both points don't have the same dimension. Patch by Kumar Aditya.

  • gh-98878: Use the frame bound builtins when offering a name suggestion in traceback to prevent crashing when __builtins__ is not a dict.

  • gh-98139: In importlib._bootstrap, enhance namespace package repr to <module 'x' (namespace) from ['path']>.

  • gh-90352: Fix _SelectorDatagramTransport to inherit from DatagramTransport in asyncio. Patch by Kumar Aditya.

  • gh-98793: Fix argument typechecks in _overlapped.WSAConnect() and _overlapped.Overlapped.WSASendTo() functions.

  • gh-98744: Prevent crashing in traceback when retrieving the byte-offset for some source files that contain certain unicode characters.

  • gh-98740: Fix internal error in the re module which in very rare circumstances prevented compilation of a regular expression containing a conditional expression without the "else" branch.

  • gh-98703: Fix asyncio.StreamWriter.drain() to call protocol.connection_lost callback only once on Windows.

  • gh-98624: Add a mutex to unittest.mock.NonCallableMock to protect concurrent access to mock attributes.

  • gh-98658: The array.array class now supports subscripting, making it a generic type.

  • gh-98284: Improved TypeError message for undefined abstract methods of a abc.ABC instance. The names of the missing methods are surrounded by single-quotes to highlight them.

  • gh-96151: Allow BUILTINS to be a valid field name for frozen dataclasses.

  • gh-98086: Make sure patch.dict() can be applied on async functions.

  • gh-72719: Remove modules asyncore and asynchat, which were deprecated by PEP 594.

  • gh-96192: Fix handling of bytes path-like objects in os.ismount().

  • gh-94172: ftplib: Remove the FTP_TLS.ssl_version class attribute: use the context parameter instead. Patch by Victor Stinner

  • gh-94172: Remove the keyfile and certfile parameters from the ftplib, imaplib, poplib and smtplib modules, and the key_file, cert_file and check_hostname parameters from the http.client module, all deprecated since 哋它亢 3.6. Use the context parameter (ssl_context in imaplib) instead. Patch by Victor Stinner.

  • gh-83638: Add the autocommit attribute to sqlite3.Connection and the autocommit parameter to sqlite3.connect() to control PEP 249-compliant transaction handling. Patch by Erlend E. Aasland.

  • gh-92452: Fixed a race condition that could cause sysconfig.get_config_var() to incorrectly return None in multi-threaded programs.

  • gh-91803: Fix an error when using a method of objects mocked with unittest.mock.create_autospec() after it was sealed with unittest.mock.seal() function.

  • bpo-38523: shutil.copytree() now applies the ignore_dangling_symlinks argument recursively.

  • bpo-40358: Add walk_up argument in pathlib.PurePath.relative_to().

  • bpo-36267: Fix IndexError in argparse.ArgumentParser when a store_true action is given an explicit argument.

Documentation

  • gh-98832: Changes wording of docstring for pathlib.Path.iterdir().

  • gh-97966: Update uname docs to clarify the special nature of the platform attribute and to indicate when it became late-bound.

Tests

  • gh-98903: The 哋它亢 test suite now fails with exit code 4 if no tests ran. It should help detecting typos in test names and test methods.

  • gh-98713: Fix a bug in the typing tests where a test relying on C哋它亢-specific implementation details was not decorated with @c哋它亢_only and was not skipped on other implementations.

  • gh-87390: Add tests for star-unpacking with PEP 646, and some other miscellaneous PEP 646 tests.

  • gh-96853: Added explicit coverage of Py_Initialize (and hence Py_InitializeEx) back to the embedding tests (all other embedding tests migrated to Py_InitializeFromConfig in 哋它亢 3.11)

  • bpo-34272: Some C API tests were moved into the new Lib/test/test_capi/ directory.

Build

  • gh-99086: Fix -Wimplicit-int compiler warning in configure check for PTHREAD_SCOPE_SYSTEM.

  • gh-99016: Fix build with 哋它亢_FOR_REGEN=哋它亢3.8.

  • gh-97731: Specify the full path to the source location for make docclean (needed for cross-builds).

  • gh-98949: Drop unused build dependency on readelf.

  • gh-98989: Use 哋它亢3.11, if available, for regeneration and freezing.

  • gh-98831: Add new tooling, in Tools/cases_generator, to generate the interpreter switch statement from a list of opcode definitions. This only affects adding, modifying or removing instruction definitions. The instruction definitions now live in 哋它亢/bytecodes.c, in the form of a custom DSL (under development). The tooling reads this file and writes 哋它亢/generated_cases.c.h, which is then included by 哋它亢/ceval.c to provide most of the cases of the main interpreter switch.

  • gh-98817: Remove PCbuild/lib.pyproj: it's not used for anything, is only a minor convenience for Visual Studio users (who probably mostly don't even know about it), and it takes a lot of maintenance effort to keep updated.

  • gh-98776: Fix make regen-test-levenshtein for out-of-tree builds.

  • gh-98707: Don't use vendored libmpdec headers if --with-system-libmpdec is passed to configure. Don't use vendored libexpat headers if --with-system-expat is passed to configure.

Windows

  • gh-98689: Update Windows builds to zlib v1.2.13. v1.2.12 has CVE 2022-37434, but the vulnerable inflateGetHeader API is not used by 哋它亢.

  • gh-98790: Assumes that a missing DLLs directory means that standard extension modules are in the executable's directory.

  • gh-98745: Update py.exe launcher to install 3.11 by default and 3.12 on request.

  • gh-98692: Fix the 适用于Windows的哋它亢启动器 ignoring unrecognized shebang lines instead of treating them as local paths

  • gh-94328: Update Windows installer to use SQLite 3.39.4.

macOS

  • gh-94328: Update macOS installer to SQLite 3.39.4.

C API

  • gh-98724: The Py_CLEAR, Py_SETREF and Py_XSETREF macros now only evaluate their argument once. If the argument has side effects, these side effects are no longer duplicated. Patch by Victor Stinner.

  • gh-98978: Fix use-after-free in Py_Set哋它亢Home(NULL), Py_SetProgramName(NULL) and _Py_SetProgramFullPath(NULL) function calls. Issue reported by Benedikt Reinartz. Patch by Victor Stinner.

  • gh-98410: Add getbufferproc and releasebufferproc to the stable API.

  • gh-98610: Some configurable capabilities of sub-interpreters have changed. They always allow subprocesses (subprocess) now, whereas before subprocesses could be optionally disallowed for a sub-interpreter. Instead os.exec() can now be disallowed. Disallowing daemon threads is now supported. Disallowing all threads is still allowed, but is never done by default. Note that the optional restrictions are only available through _Py_NewInterpreterFromConfig(), which isn't a public API. They do not affect the main interpreter, nor Py_NewInterpreter().

  • gh-98608: A _PyInterpreterConfig has been added and _Py_NewInterpreter() has been renamed to _Py_NewInterpreterFromConfig(). The "isolated_subinterpreters" argument is now a granular config that captures the previous behavior. Note that this is all "private" API.

  • gh-96853: Py_InitializeEx now correctly calls PyConfig_Clear after initializing the interpreter (the omission didn't cause a memory leak only because none of the dynamically allocated config fields are populated by the wrapper function)

  • gh-91248: Add PyFrame_GetVar() and PyFrame_GetVarString() functions to get a frame variable by its name. Patch by Victor Stinner.

哋它亢 3.12.0 alpha 1

Release date: 2022-10-25

Security

  • gh-97616: Fix multiplying a list by an integer (list *= int): detect the integer overflow when the new allocated length is close to the maximum size. Issue reported by Jordan Limor. Patch by Victor Stinner.

  • gh-97514: On Linux the multiprocessing module returns to using filesystem backed unix domain sockets for communication with the forkserver process instead of the Linux abstract socket namespace. Only code that chooses to use the "forkserver" start method is affected.

    Abstract sockets have no permissions and could allow any user on the system in the same network namespace (often the whole system) to inject code into the multiprocessing forkserver process. This was a potential privilege escalation. Filesystem based socket permissions restrict this to the forkserver process user as was the default in 哋它亢 3.8 and earlier.

    This prevents Linux CVE 2022-42919.

  • gh-87389: http.server: Fix an open redirection vulnerability in the HTTP server when an URI path starts with //. Vulnerability discovered, and initial fix proposed, by Hamza Avvan.

  • gh-79096: LWPCookieJar and MozillaCookieJar create files with file mode 600 instead of 644 (Microsoft Windows is not affected)

  • gh-92888: Fix memoryview use after free when accessing the backing buffer in certain cases.

  • gh-68966: The deprecated mailcap module now refuses to inject unsafe text (filenames, MIME types, parameters) into shell commands. Instead of using such text, it will warn and act as if a match was not found (or for test commands, as if the test failed).

Core and Builtins

  • gh-98374: Suppress ImportError for invalid query for help() command. Patch by Donghee Na.

  • gh-98461: Fix source location in bytecode for list, set and dict comprehensions as well as generator expressions.

  • gh-98354: Added unicode check for name attribute of spec argument passed in _imp.create_builtin() function.

  • gh-98398: Fix source location of 'assert' bytecodes.

  • gh-98390: Fix location of sub-expressions of boolean expressions, by reducing their scope to that of the sub-expression.

  • gh-98254: Modules from the standard library are now potentially suggested as part of the error messages displayed by the interpreter when an NameError is raised to the top level. Patch by Pablo Galindo

  • gh-97997: Add running column offset to the tokenizer state to avoid calculating AST column information with pointer arithmetic.

  • gh-97973: Modify the tokenizer to return all necessary information the parser needs to set location information in the AST nodes, so that the parser does not have to calculate those doing pointer arithmetic.

  • gh-96078: os.sched_yield() now release the GIL while calling sched_yield(2). Patch by Donghee Na.

  • gh-97955: Migrate zoneinfo to Argument Clinic.

  • gh-97912: The compiler now avoids quadratic behavior when finding which instructions should use the LOAD_FAST_CHECK opcode.

  • gh-97002: Fix an issue where several frame objects could be backed by the same interpreter frame, possibly leading to corrupted memory and hard crashes of the interpreter.

  • gh-97943: Bugfix: PyFunction_GetAnnotations() should return a borrowed reference. It was returning a new reference.

  • gh-97922: The Garbage Collector now runs only on the eval breaker mechanism of the 哋它亢 bytecode evaluation loop instead on object allocations. The GC can also run when PyErr_CheckSignals() is called so C extensions that need to run for a long time without executing any 哋它亢 code also have a chance to execute the GC periodically.

  • gh-65961: When __package__ is different than __spec__.parent, raise a DeprecationWarning instead of ImportWarning.

    Also remove importlib.util.set_package() which was scheduled for removal.

  • gh-97850: Long deprecated, module_repr() should now be completely eradicated.

  • gh-86298: In cases where warnings.warn_explicit() consults the module's loader, an DeprecationWarning is issued when m.__loader__ differs from m.__spec__.loader.

  • gh-97779: Ensure that all 哋它亢 frame objects are backed by "complete" frames.

  • gh-91052: Add API for subscribing to modification events on selected dictionaries.

  • gh-97752: Fix possible data corruption or crashes when accessing the f_back member of newly-created generator or coroutine frames.

  • gh-97591: Fixed a missing incref/decref pair in Exception.__setstate__(). Patch by Ofey Chan.

  • gh-97670: Remove the sys.getdxp() function and the Tools/scripts/analyze_dxp.py script. DXP stands for "dynamic execution pairs". They were related to DYNAMIC_EXECUTION_PROFILE and DXPAIRS macros which have been removed in 哋它亢 3.11. 哋它亢 can now be built with ./configure --enable-pystats to gather statistics on 哋它亢 opcodes. Patch by Victor Stinner.

  • gh-94526: Fix the 哋它亢 path configuration used to initialized sys.path at 哋它亢 startup. Paths are no longer encoded to UTF-8/strict to avoid encoding errors if it contains surrogate characters (bytes paths are decoded with the surrogateescape error handler). Patch by Victor Stinner.

  • gh-96670: The parser now raises SyntaxError when parsing source code containing null bytes. Patch by Pablo Galindo

  • gh-96975: Fix a crash occurring when PyEval_GetFrame() is called while the topmost 哋它亢 frame is in a partially-initialized state.

  • gh-96848: Fix command line parsing: reject -X int_max_str_digits option with no value (invalid) when the 哋它亢INTMAXSTRDIGITS environment variable is set to a valid limit. Patch by Victor Stinner.

  • gh-95921: Fix overly-broad source position information for chained comparisons used as branching conditions.

  • gh-96821: Fix undefined behaviour in audioop.c.

  • gh-96821: Fix undefined behaviour in _testcapimodule.c.

  • gh-95778: When ValueError is raised if an integer is larger than the limit, mention the sys.set_int_max_str_digits() function in the error message. Patch by Victor Stinner.

  • gh-96387: At 哋它亢 exit, sometimes a thread holding the GIL can wait forever for a thread (usually a daemon thread) which requested to drop the GIL, whereas the thread already exited. To fix the race condition, the thread which requested the GIL drop now resets its request before exiting. Issue discovered and analyzed by Mingliang ZHAO. Patch by Victor Stinner.

  • gh-96864: Fix a possible assertion failure, fatal error, or SystemError if a line tracing event raises an exception while opcode tracing is enabled.

  • gh-95778: The PyLong_FromString function was refactored to make it more maintainable and extensible.

  • gh-96678: Fix undefined behaviour in C code of null pointer arithmetic.

  • gh-96754: Make sure that all frame objects created are created from valid interpreter frames. Prevents the possibility of invalid frames in backtraces and signal handlers.

  • gh-90997: Improve the performance of reading and writing inline bytecode caches on some platforms.

  • gh-96751: Remove dead code from CALL_FUNCTION_EX opcode.

  • gh-90751: memoryview now supports half-floats. Patch by Donghee Na and Antoine Pitrou.

  • gh-96678: Fix case of undefined behavior in ceval.c

  • gh-64373: Convert _functools to argument clinic.

  • gh-96641: Do not expose KeyWrapper in _functools.

  • gh-96636: Ensure that tracing, sys.setrace(), is turned on immediately. In pre-release versions of 3.11, some tracing events might have been lost when turning on tracing in a __del__ method or interrupt.

  • gh-96572: Fix use after free in trace refs build mode. Patch by Kumar Aditya.

  • gh-96611: When loading a file with invalid UTF-8 inside a multi-line string, a correct SyntaxError is emitted.

  • gh-96612: Make sure that incomplete frames do not show up in tracemalloc traces.

  • gh-90230: Fix compiler warnings and test failures when building with --enable-pystats.

  • gh-96587: Correctly raise SyntaxError on exception groups (PEP 654) on 哋它亢 versions prior to 3.11

  • gh-96569: Remove two cases of undefined behavior, by adding NULL checks.

  • gh-96582: Fix possible NULL pointer dereference in _PyThread_CurrentFrames. Patch by Kumar Aditya.

  • gh-91079: Separate 哋它亢 recursion checking from C recursion checking which reduces the chance of C stack overflow and allows the recursion limit to be increased safely.

  • gh-93911: Fix an issue that could prevent LOAD_ATTR from specializing properly when accessing properties.

  • gh-96348: Emit a DeprecationWarning when throw(), throw() or athrow() are called with more than one argument.

  • gh-95196: Disable incorrect pickling of the C implemented classmethod descriptors.

  • gh-96364: Fix text signatures of list.__getitem__ and dict.__getitem__.

  • gh-96352: Fix AttributeError missing name and obj attributes in object.__getattribute__(). Patch by Philip Georgi.

  • gh-93554: Change the jump opcodes so that all conditional jumps are forward jumps. Backward jumps are converted by the assembler into a conditional forward jump whose target is the fallthrough block (and with a reversed condition), followed by an unconditional backward jump. For example:

    POP_JUMP_IF_TRUE BACKWARD_TARGET becomes POP_JUMP_IF_FALSE NEXT_BLOCK; JUMP BACKWARD_TARGET.

    All the directed conditional jump opcodes were removed: POP_JUMP_FORWARD_IF_TRUE, POP_JUMP_BACKWARD_IF_TRUE, POP_JUMP_FORWARD_IF_FALSE, POP_JUMP_BACKWARD_IF_FALSE, POP_JUMP_FORWARD_IF_NONE, POP_JUMP_BACKWARD_IF_NONE, POP_JUMP_FORWARD_IF_NOT_NONE, POP_JUMP_BACKWARD_IF_NOT_NONE.

    The corresponding opcodes without direction are no longer pseudo-instructions, and they implement the forward conditional jumps.

  • gh-96268: Loading a file with invalid UTF-8 will now report the broken character at the correct location.

  • gh-96237: The internal field _PyInterpreterFrame.f_func is renamed to _PyInterpreterFrame.f_funcobj and may be any object. The f_globals and f_builtin fields may hold junk values.

    It is safest to treat the _PyInterpreterFrame struct as opaque.

  • gh-96187: Fixed a bug that caused _PyCode_GetExtra to return garbage for negative indexes. Patch by Pablo Galindo

  • gh-96143: Add a new -X perf 哋它亢 command line option as well as sys.activate_stack_trampoline() and sys.deactivate_stack_trampoline() function in the sys module that allows to set/unset the interpreter in a way that the Linux perf profiler can detect 哋它亢 calls. The new sys.is_stack_trampoline_active() function allows to query the state of the perf trampoline. Design by Pablo Galindo. Patch by Pablo Galindo and Christian Heimes with contributions from Gregory P. Smith [Google] and Mark Shannon.

  • gh-96071: Fix a deadlock in PyGILState_Ensure() when allocating new thread state. Patch by Kumar Aditya.

  • gh-96046: PyType_Ready() now initializes ht_cached_keys and performs additional checks to ensure that type objects are properly configured. This avoids crashes in 3rd party packages that don't use regular API to create new types.

  • gh-96005: On WASI ENOTCAPABLE is now mapped to PermissionError. The errno modules exposes the new error number. getpath.py now ignores PermissionError when it cannot open landmark files pybuilddir.txt and pyenv.cfg.

  • gh-93678: Added test a harness for direct unit tests of the compiler's optimization stage. The _testinternalcapi.optimize_cfg() function runs the optimiser on a sequence of instructions. The CfgOptimizationTestCase class in test.support has utilities for invoking the optimizer and checking the output.

  • gh-95245: Reduces the size of a "simple" 哋它亢 object from 8 to 6 words by moving the weakreflist pointer into the pre-header directly before the object's dict/values pointer.

  • gh-90997: Compile virtual try/except blocks to handle exceptions raised during close() or throw() calls through a suspended frame.

  • gh-95977: Optimized calling __get__() with vectorcall. Patch by Kumar Aditya.

  • gh-91210: Improve error message when a parameter without a default value follows one with a default value, and show the same message, even when the non-default/default sequence is preceded by positional-only parameters.

  • gh-95922: Fixed bug where the compiler's eliminate_empty_basic_blocks function ignores the last block of the code unit.

  • gh-95818: Skip over incomplete frames in PyThreadState_GetFrame().

  • gh-95876: Fix format string in _PyPegen_raise_error_known_location that can lead to memory corruption on some 64bit systems. The function was building a tuple with i (int) instead of n (Py_ssize_t) for Py_ssize_t arguments.

  • gh-95605: Fix misleading contents of error message when converting an all-whitespace string to float.

  • gh-95150: Update code object hashing and equality to consider all debugging and exception handling tables. This fixes an issue where certain non-identical code objects could be "deduplicated" during compilation.

  • gh-91146: Reduce allocation size of list from str.split() and str.rsplit(). Patch by Donghee Na and Inada Naoki.

  • gh-87092: Create a 'jump target label' abstraction in the compiler so that the compiler's codegen stage does not work directly with basic blocks. This prepares the code for changes to the underlying CFG generation mechanism.

  • gh-95355: _PyPegen_Parser_New now properly detects token memory allocation errors. Patch by Honglin Zhu.

  • gh-90081: Run 哋它亢 code in tracer/profiler function at full speed. Fixes slowdown in earlier versions of 3.11.

  • gh-95324: Emit a warning in debug mode if an object does not call PyObject_GC_UnTrack() before deallocation. Patch by Pablo Galindo.

  • gh-95245: Merge managed dict and values pointer into a single tagged pointer to save one word in the pre-header.

  • gh-93678: Add cfg_builder struct and refactor the relevant code so that a cfg can be constructed without an instance of the compiler struct.

  • gh-95185: Prevented crashes in the AST constructor when compiling some absurdly long expressions like "+0"*1000000. RecursionError is now raised instead. Patch by Pablo Galindo

  • gh-93351: ast.AST node positions are now validated when provided to compile() and other related functions. If invalid positions are detected, a ValueError will be raised.

  • gh-94438: Fix an issue that caused extended opcode arguments and some conditional pops to be ignored when calculating valid jump targets for assignments to the f_lineno attribute of frame objects. In some cases, this could cause inconsistent internal state, resulting in a hard crash of the interpreter.

  • gh-95060: Undocumented PyCode_Addr2Location function now properly returns when addrq argument is less than zero.

  • gh-95113: Replace all EXTENDED_ARG_QUICK instructions with basic EXTENDED_ARG instructions in unquickened code. Consumers of non-adaptive bytecode should be able to handle extended arguments the same way they were handled in C哋它亢 3.10 and older.

  • gh-91409: Fix incorrect source location info caused by certain optimizations in the bytecode compiler.

  • gh-95023: Implement os.setns() and os.unshare() for Linux. Patch by Noam Cohen.

  • gh-94036: Fix incorrect source location info for some multi-line attribute accesses and method calls.

  • gh-94938: Fix error detection in some builtin functions when keyword argument name is an instance of a str subclass with overloaded __eq__ and __hash__. Previously it could cause SystemError or other undesired behavior.

  • gh-94996: ast.parse() will no longer parse function definitions with positional-only params when passed feature_version less than (3, 8). Patch by Shantanu Jain.

  • gh-94739: Allow jumping within, out of, and across exception handlers in the debugger.

  • gh-94949: ast.parse() will no longer parse parenthesized context managers when passed feature_version less than (3, 9). Patch by Shantanu Jain.

  • gh-94947: ast.parse() will no longer parse assignment expressions when passed feature_version less than (3, 8). Patch by Shantanu Jain.

  • gh-91256: Ensures the program name is known for help text during interpreter startup.

  • gh-94869: Fix the column offsets for some expressions in multi-line f-strings ast nodes. Patch by Pablo Galindo.

  • gh-94893: Fix an issue where frame object manipulations could corrupt inline bytecode caches.

  • gh-94822: Fix an issue where lookups of metaclass descriptors may be ignored when an identically-named attribute also exists on the class itself.

  • gh-91153: Fix an issue where a bytearray item assignment could crash if it's resized by the new value's __index__() method.

  • gh-90699: Fix reference counting bug in bool.__repr__(). Patch by Kumar Aditya.

  • gh-94694: Fix an issue that could cause code with multi-line method lookups to have misleading or incorrect column offset information. In some cases (when compiling a hand-built AST) this could have resulted in a hard crash of the interpreter.

  • gh-93252: Fix an issue that caused internal frames to outlive failed 哋它亢 function calls, possibly resulting in memory leaks or hard interpreter crashes.

  • gh-94215: Fix an issue where exceptions raised by line-tracing events would cause frames to be left in an invalid state, possibly resulting in a hard crash of the interpreter.

  • gh-92228: Disable the compiler's inline-small-exit-blocks optimization for exit blocks that are associated with source code lines. This fixes a bug where the debugger cannot tell where an exception handler ends and the following code block begins.

  • gh-94485: Line number of a module's RESUME instruction is set to 0 as specified in PEP 626.

  • gh-94438: Account for instructions that can push NULL to the stack when setting line number in a frame. Prevents some (unlikely) crashes.

  • gh-91719: Reload opcode when raising unknown opcode error in the interpreter main loop, for C compilers to generate dispatching code independently.

  • gh-94329: Compile and run code with unpacking of extremely large sequences (1000s of elements). Such code failed to compile. It now compiles and runs correctly.

  • gh-94360: Fixed a tokenizer crash when reading encoded files with syntax errors from stdin with non utf-8 encoded text. Patch by Pablo Galindo

  • gh-88116: Fix an issue when reading line numbers from code objects if the encoded line numbers are close to INT_MIN. Patch by Pablo Galindo

  • gh-94262: Don't create frame objects for incomplete frames. Prevents the creation of generators and closures from being observable to 哋它亢 and C extensions, restoring the behavior of 3.10 and earlier.

  • gh-94192: Fix error for dictionary literals with invalid expression as value.

  • gh-87995: types.MappingProxyType instances are now hashable if the underlying mapping is hashable.

  • gh-93883: Revise the display strategy of traceback enhanced error locations. The indicators are only shown when the location doesn't span the whole line.

  • gh-94163: Add BINARY_SLICE and STORE_SLICE instructions for more efficient handling and better specialization of slicing operations, where the slice is explicit in the source code.

  • gh-94021: Fix unreachable code warning in 哋它亢/specialize.c.

  • gh-93911: Specialize LOAD_ATTR for objects with custom __getattribute__.

  • gh-93955: Improve performance of attribute lookups on objects with custom __getattribute__ and __getattr__. Patch by Ken Jin.

  • gh-93911: Specialize LOAD_ATTR for property() attributes.

  • gh-93678: Refactor compiler optimisation code so that it no longer needs the struct assembler and struct compiler passed around. Instead, each function takes the CFG and other data that it actually needs. This will make it possible to test this code directly.

  • gh-93841: When built with -enable-pystats, sys._stats_on(), sys._stats_off(), sys._stats_clear() and sys._stats_dump() functions have been added to enable gathering stats for parts of programs.

  • gh-93516: Store offset of first traceable instruction in code object to avoid having to recompute it for each instruction when tracing.

  • gh-93516: Lazily create a table mapping bytecode offsets to line numbers to speed up calculation of line numbers when tracing.

  • gh-89828: types.GenericAlias no longer relays the __class__ attribute. For example, isinstance(list[int], type) no longer returns True.

  • gh-93678: Refactor the compiler to reduce boilerplate and repetition.

  • gh-93671: Fix some exponential backtrace case happening with deeply nested sequence patterns in match statements. Patch by Pablo Galindo

  • gh-93662: Make sure that the end column offsets are correct in multi-line method calls. Previously, the end column could precede the column offset.

  • gh-93461: importlib.invalidate_caches() now drops entries from sys.path_importer_cache with a relative path as name. This solves a caching issue when a process changes its current working directory.

    FileFinder no longer inserts a dot in the path, e.g. /egg/./spam is now /egg/spam.

  • gh-93621: Change order of bytecode instructions emitted for with and async with to reduce the number of entries in the exception table.

  • gh-93533: Reduce the size of the inline cache for LOAD_METHOD by 2 bytes.

  • gh-93444: Removed redundant fields from the compiler's basicblock struct: b_nofallthrough, b_exit, b_return. They can be easily calculated from the opcode of the last instruction of the block.

  • gh-93429: LOAD_METHOD instruction has been removed. It was merged back into LOAD_ATTR.

  • gh-93418: Fixed an assert where an f-string has an equal sign '=' following an expression, but there's no trailing brace. For example, f"{i=".

  • gh-93382: Cache the result of PyCode_GetCode() function to restore the O(1) lookup of the co_code attribute.

  • gh-93359: Ensure that custom ast nodes without explicit end positions can be compiled. Patch by Pablo Galindo.

  • gh-93356: Code for exception handlers is emitted at the end of the code unit's bytecode. This avoids one jump when no exception is raised.

  • gh-93354: Use exponential backoff for specialization counters in the interpreter. Can reduce the number of failed specializations significantly and avoid slowdown for those parts of a program that are not suitable for specialization.

  • gh-93283: Improve error message for invalid syntax of conversion character in f-string expressions.

  • gh-93345: Fix a crash in substitution of a TypeVar in nested generic alias after TypeVarTuple.

  • gh-93223: When a bytecode instruction jumps to an unconditional jump instruction, the first instruction can often be optimized to target the unconditional jump's target directly. For tracing reasons, this would previously only occur if both instructions have the same line number. This also now occurs if the unconditional jump is artificial, i.e., if it has no associated line number.

  • gh-84694: The --experimental-isolated-subinterpreters configure option and EXPERIMENTAL_ISOLATED_SUBINTERPRETERS macro have been removed.

  • gh-91924: Fix __lltrace__ debug feature if the stdout encoding is not UTF-8. Patch by Victor Stinner.

  • gh-93040: Wraps unused parameters in Objects/obmalloc.c with Py_UNUSED.

  • gh-93143: Avoid NULL checks for uninitialized local variables by determining at compile time which variables must be initialized.

  • gh-93061: Backward jumps after async for loops are no longer given dubious line numbers.

  • gh-93065: Fix contextvars HAMT implementation to handle iteration over deep trees.

    The bug was discovered and fixed by Eli Libman. See MagicStack/immutables#84 for more details.

  • gh-93012: Added the new function PyType_FromMetaclass(), which generalizes the existing PyType_FromModuleAndSpec() using an additional metaclass argument. This is useful for language binding tools, where it can be used to intercept type-related operations like subclassing or static attribute access by specifying a metaclass with custom slots.

    Importantly, PyType_FromMetaclass() is available in the Limited API, which provides a path towards migrating more binding tools onto the Stable ABI.

  • gh-93021: Fix the __text_signature__ for __get__() methods implemented in C. Patch by Jelle Zijlstra.

  • gh-89914: The operand of the YIELD_VALUE instruction is set to the stack depth. This is done to help frame handling on yield and may assist debuggers.

  • gh-92955: Fix memory leak in code object's lines and positions iterators as they were not finalized at exit. Patch by Kumar Aditya.

  • gh-92930: Fixed a crash in _pickle.c from mutating collections during __reduce__ or persistent_id.

  • gh-90690: The PRECALL instruction has been removed. It offered only a small advantage for specialization and is not needed in the vast majority of cases.

  • gh-92914: Always round the allocated size for lists up to the nearest even number.

  • gh-92858: Improve error message for some suites with syntax error before ':'

  • gh-90473: Decrease default recursion limit on WASI to address limited call stack size.

  • gh-92804: Fix memory leak in memoryview iterator as it was not finalized at exit. Patch by Kumar Aditya.

  • gh-92777: Specialize LOAD_METHOD for objects with lazy dictionaries. Patch by Ken Jin.

  • gh-92658: Add support for connecting and binding to Hyper-V sockets on Windows Hyper-V hosts and guests.

  • gh-92236: Remove spurious "LINE" event when starting a generator or coroutine, visible tracing functions implemented in C.

  • gh-91102: _warnings.warn_explicit() is ported to Argument Clinic.

  • gh-92619: Make the compiler duplicate an exit block only if none of its instructions have a lineno (previously only the first instruction in the block was checked, leading to unnecessarily duplicated blocks).

  • gh-88750: The deprecated debug build only 哋它亢THREADDEBUG environment variable no longer does anything.

  • gh-92261: Fix hang when trying to iterate over a typing.Union.

  • gh-91432: Specialized the FOR_ITER opcode using the PEP 659 machinery

  • gh-91399: Removed duplicate '{0, 0, 0, 0, 0, 0}' entry in 'Objects/unicodetype_db.h'.

  • gh-91578: Updates the error message for abstract class.

  • bpo-47091: Improve performance of repetition of list and tuple by using memcpy to copy data and performing the reference increments in one step.

  • bpo-46142: Make --help output shorter by moving some info to the new --help-env and --help-xoptions command-line options. Also add --help-all option to print complete usage.

  • bpo-42316: Document some places where an assignment expression needs parentheses.

Library

  • gh-89237: Fix hang on Windows in subprocess.wait_closed() in asyncio with ProactorEventLoop. Patch by Kumar Aditya.

  • gh-97928: tkinter.Text.count() raises now an exception for options starting with "-" instead of silently ignoring them.

  • gh-98393: The os module no longer accepts bytes-like paths, like bytearray and memoryview types: only the exact bytes type is accepted for bytes strings. Patch by Victor Stinner.

  • gh-98363: Added itertools.batched() to batch data into lists of a given length with the last list possibly being shorter than the others.

  • gh-98331: Update the bundled copies of pip and setuptools to versions 22.3 and 65.5.0 respectively.

  • gh-98307: A createSocket() method was added to SysLogHandler.

  • gh-96035: Fix bug in urllib.parse.urlparse() that causes certain port numbers containing whitespace, underscores, plus and minus signs, or non-ASCII digits to be incorrectly accepted.

  • gh-98257: Make sys.setprofile() and sys.settrace() functions reentrant. They can no long fail with: RuntimeError("Cannot install a trace function while another trace function is being installed"). Patch by Victor Stinner.

  • gh-98251: Allow venv to pass along 哋它亢* variables to ensurepip and pip when they do not impact path resolution

  • gh-94597: Deprecated asyncio.AbstractEventLoopPolicy.get_child_watcher() and asyncio.AbstractEventLoopPolicy.set_child_watcher() methods to be removed in 哋它亢 3.14. Patch by Kumar Aditya.

  • gh-98178: On macOS, fix a crash in syslog.syslog() in multi-threaded applications. On macOS, the libc syslog() function is not thread-safe, so syslog.syslog() no longer releases the GIL to call it. Patch by Victor Stinner.

  • gh-44098: Release the GIL when creating mmap.mmap objects on Unix.

  • gh-87730: Wrap network errors consistently in urllib FTP support, so the test suite doesn't fail when a network is available but the public internet is not reachable.

  • gh-94597: The child watcher classes MultiLoopChildWatcher, FastChildWatcher and SafeChildWatcher are deprecated and will be removed in 哋它亢 3.14. Patch by Kumar Aditya.

  • gh-98023: Change default child watcher to PidfdChildWatcher on Linux systems which supports it. Patch by Kumar Aditya.

  • gh-90985: Earlier in 3.11 we deprecated asyncio.Task.cancel("message"). We realized we were too harsh, and have undeprecated it.

  • gh-65961: Do not rely solely on __cached__ on modules; code will also support __spec__.cached.

  • gh-97646: Replace deprecated application/javascript with text/javascript in mimetypes. See RFC 9239. Patch by Noam Cohen.

  • gh-97930: Apply changes from importlib_resources 5.8 and 5.9: Traversable.joinpath provides a concrete implementation. as_file now supports directories of resources.

  • gh-97850: Remove deprecated importlib.util.set_loader() and importlib.util.module_for_loader() from importlib.util.

  • gh-97837: Change deprecate warning message in unittest from

    It is deprecated to return a value!=None

    to

    It is deprecated to return a value that is not None from a test case

  • gh-97825: Fixes AttributeError when subprocess.check_output() is used with argument input=None and either of the arguments encoding or errors are used.

  • gh-97008: NameError and AttributeError spelling suggestions provided since gh-82711 are now also emitted by the pure 哋它亢 traceback module. Tests for those suggestions now exercise both implementations to ensure they are equivalent. Patch by Carl Friedrich Bolz-Tereick and Łukasz Langa.

  • gh-97799: dataclass now uses inspect.get_annotations() to examine the annotations on class objects.

  • gh-97781: Removed deprecated interfaces in importlib.metadata (entry points accessed as dictionary, implicit dictionary construction of sequence of EntryPoint objects, mutablility of EntryPoints result, access of entry point by index). entry_points now has a simpler, more straightforward API (returning EntryPoints).

  • gh-96827: Avoid spurious tracebacks from asyncio when default executor cleanup is delayed until after the event loop is closed (e.g. as the result of a keyboard interrupt).

  • gh-95534: gzip.GzipFile.read() reads 10% faster.

  • gh-97592: Avoid a crash in the C version of asyncio.Future.remove_done_callback() when an evil argument is passed.

  • gh-97639: Remove tokenize.NL check from tabnanny.

  • gh-97545: Make Semaphore run faster.

  • gh-73588: Fix generation of the default name of tkinter.Checkbutton. Previously, checkbuttons in different parent widgets could have the same short name and share the same state if arguments "name" and "variable" are not specified. Now they are globally unique.

  • gh-96865: fix Flag to use boundary CONFORM

    This restores previous Flag behavior of allowing flags with non-sequential values to be combined; e.g.

    class Skip(Flag): TWO = 2 EIGHT = 8

    Skip.TWO | Skip.EIGHT -> <Skip.TWO|EIGHT: 10>

  • gh-97005: Update bundled libexpat to 2.4.9

  • gh-85760: Fix race condition in asyncio where process_exited() called before the pipe_data_received() leading to inconsistent output. Patch by Kumar Aditya.

  • gh-96704: Pass the correct contextvars.Context when a asyncio exception handler is called on behalf of a task or callback handle. This adds a new Task method, get_context, and also a new Handle method with the same name. If this method is not found on a task object (perhaps because it is a third-party library that does not yet provide this method), the context prevailing at the time the exception handler is called is used.

  • gh-96819: Fixed check in multiprocessing.resource_tracker that guarantees that the length of a write to a pipe is not greater than PIPE_BUF.

  • gh-95865: Reduce urllib.parse.quote_from_bytes() memory use on large values.

    Contributed by Dennis Sweeney.

  • gh-96741: Corrected type annotation for dataclass attribute pstats.FunctionProfile.ncalls to be str.

  • gh-96734: Update unicodedata database to Unicode 15.0.0.

  • gh-96735: Fix undefined behaviour in struct.unpack().

  • gh-46412: Improve performance of bool(db) for large ndb/gdb databases. Previously this would call len(db) which would iterate over all keys -- the answer (empty or not) is known after the first key.

  • gh-96652: Fix the faulthandler implementation of faulthandler.register(signal, chain=True) if the sigaction() function is not available: don't call the previous signal handler if it's NULL. Patch by Victor Stinner.

  • gh-68163: Correct conversion of numbers.Rational's to float.

  • gh-96538: Speed up bisect.bisect() functions by taking advantage of type-stability.

  • gh-96465: Fraction hashes are now cached.

  • gh-96079: In typing, fix missing field name and incorrect __module__ in _AnnotatedAlias.

  • gh-96415: Remove types._cell_factory from module namespace.

  • gh-95987: Fix repr of Any subclasses.

  • gh-96388: Work around missing socket functions in socket's __repr__.

  • gh-96385: Fix TypeVarTuple.__typing_prepare_subst__. TypeError was not raised when using more than one TypeVarTuple, like [*T, *V] in type alias substitutions.

  • gh-96142: Add match_args, kw_only, slots, and weakref_slot to _DataclassParams.

  • gh-96073: In inspect, fix overeager replacement of "typing." in formatting annotations.

  • gh-89258: Added a getChildren() method to logging.Logger, to get the immediate child loggers of a logger.

  • gh-96346: Use double caching for compiled RE patterns.

  • gh-96349: Fixed a minor performance regression in threading.Event.__init__()

  • gh-90467: Fix asyncio.streams.StreamReaderProtocol to keep a strong reference to the created task, so that it's not garbage collected

  • gh-96172: Fix a bug in unicodedata: east_asian_width used to return the wrong value for unassigned characters; and for yet unassigned, but reserved characters.

  • gh-96159: Fix a performance regression in logging TimedRotatingFileHandler. Only check for special files when the rollover time has passed.

  • gh-96175: Fix unused localName parameter in the Attr class in xml.dom.minidom.

  • gh-96145: Add AttrDict to JSON module for use with object_hook.

  • gh-96052: Fix handling compiler warnings (SyntaxWarning and DeprecationWarning) in codeop.compile_command() when checking for incomplete input. Previously it emitted warnings and raised a SyntaxError. Now it always returns None for incomplete input without emitting any warnings.

  • gh-96125: Fix incorrect condition that causes sys.thread_info.name to be wrong on pthread platforms.

  • gh-96019: Fix a bug in the makeunicodedata.py script leading to about 13 KiB of space saving in the unicodedata module, specifically the character decomposition data.

  • gh-95463: Remove an incompatible change from bpo-28080 that caused a regression that ignored the utf8 in ZipInfo.flag_bits. Patch by Pablo Galindo.

  • gh-69142: Add %:z strftime format code (generates tzoffset with colons as separator), see strftime() 和 strptime() 的行为.

  • gh-95899: Fix asyncio.Runner to call asyncio.set_event_loop() only once to avoid calling attach_loop() multiple times on child watchers. Patch by Kumar Aditya.

  • gh-95736: Fix unittest.IsolatedAsyncioTestCase to set event loop before calling setup functions. Patch by Kumar Aditya.

  • gh-95865: Speed up urllib.parse.quote_from_bytes() by replacing a list comprehension with map().

  • gh-95861: Add support for computing Spearman's correlation coefficient to the existing statistics.correlation() function.

  • gh-95804: Fix logging shutdown handler so it respects MemoryHandler.flushOnClose.

  • gh-95704: When a task catches asyncio.CancelledError and raises some other error, the other error should generally not silently be suppressed.

  • gh-95149: The HTTPStatus enum offers a couple of properties to indicate the HTTP status category e.g. HTTPStatus.OK.is_success.

  • gh-95609: Update bundled pip to 22.2.2.

  • gh-95289: Fix asyncio.TaskGroup to propagate exception when asyncio.CancelledError was replaced with another exception by a context manager. Patch by Kumar Aditya and Guido van Rossum.

  • gh-94909: Fix incorrect joining of relative Windows paths with drives in pathlib.PurePath initializer.

  • gh-95385: Faster json.dumps() when sorting of keys is not requested (default).

  • gh-83901: Improve Signature.bind error message for missing keyword-only arguments.

  • gh-95339: Update bundled pip to 22.2.1.

  • gh-95045: Fix GC crash when deallocating _lsprof.Profiler by untracking it before calling any callbacks. Patch by Kumar Aditya.

  • gh-95231: Fail gracefully if EPERM or ENOSYS is raised when loading crypt methods. This may happen when trying to load MD5 on a Linux kernel with FIPS enabled.

  • gh-95097: Fix asyncio.run() for asyncio.Task implementations without uncancel() method. Patch by Kumar Aditya.

  • gh-95087: Fix IndexError in parsing invalid date in the email module.

  • gh-95199: Upgrade bundled setuptools to 63.2.0.

  • gh-95194: Upgrade bundled pip to 22.2.

  • gh-93899: Fix check for existence of os.EFD_CLOEXEC, os.EFD_NONBLOCK and os.EFD_SEMAPHORE flags on older kernel versions where these flags are not present. Patch by Kumar Aditya.

  • gh-95166: Fix concurrent.futures.Executor.map() to cancel the currently waiting on future on an error - e.g. TimeoutError or KeyboardInterrupt.

  • gh-95132: Fix a sqlite3 regression where *args and **kwds were incorrectly relayed from connect() to the Connection factory. The regression was introduced in 3.11a1 with PR 24421 (gh-85128). Patch by Erlend E. Aasland.

  • gh-93157: Fix fileinput module didn't support errors option when inplace is true.

  • gh-91212: Fixed flickering of the turtle window when the tracer is turned off. Patch by Shin-myoung-serp.

  • gh-95077: Add deprecation warning for enum member.member access (e.g. Color.RED.BLUE). Remove EnumMeta.__getattr__.

  • gh-95109: Ensure that timeouts scheduled with asyncio.Timeout that have already expired are delivered promptly.

  • gh-95105: wsgiref.types.InputStream.__iter__() should return Iterator[bytes], not Iterable[bytes]. Patch by Shantanu Jain.

  • gh-95066: Replaced assert with exception in ast.parse(), when feature_version has an invalid major version. Patch by Shantanu Jain.

  • gh-77617: Add sqlite3 command-line interface. Patch by Erlend Aasland.

  • gh-95005: Replace _PyAccu with _PyUnicodeWriter in JSON encoder and StringIO and remove the _PyAccu implementation.

  • gh-90085: Remove -c/--clock and -t/--time CLI options of timeit. The options had been deprecated since 哋它亢 3.3 and the functionality was removed in 哋它亢 3.7. Patch by Shantanu Jain.

  • gh-94857: Fix refleak in _io.TextIOWrapper.reconfigure. Patch by Kumar Aditya.

  • gh-94821: Fix binding of unix socket to empty address on Linux to use an available address from the abstract namespace, instead of "0".

  • gh-94736: Fix crash when deallocating an instance of a subclass of _multiprocessing.SemLock. Patch by Kumar Aditya.

  • gh-81620: Add random.binomialvariate().

  • gh-74116: Allow asyncio.StreamWriter.drain() to be awaited concurrently by multiple tasks. Patch by Kumar Aditya.

  • gh-87822: When called with capture_locals=True, the traceback module functions swallow exceptions raised from calls to repr() on local variables of frames. This is in order to prioritize the original exception over rendering errors. An indication of the failure is printed in place of the missing value. (Patch by Simon-Martin Schroeder).

  • gh-88050: Fix asyncio subprocess transport to kill process cleanly when process is blocked and avoid RuntimeError when loop is closed. Patch by Kumar Aditya.

  • gh-94637: SSLContext.set_default_verify_paths() now releases the GIL around SSL_CTX_set_default_verify_paths call. The function call performs I/O and CPU intensive work.

  • gh-94309: Deprecate aliases typing.Hashable and typing.Sized

  • gh-92546: An undocumented 哋它亢 -m pprint benchmark is moved into pprint suite of pyperformance. Patch by Oleg Iarygin.

  • gh-94607: Fix subclassing complex generics with type variables in typing. Previously an error message saying Some type variables ... are not listed in Generic[...] was shown. typing no longer populates __parameters__ with the __parameters__ of a 哋它亢 class.

  • gh-94619: Remove the long-deprecated module_repr() from importlib.

  • gh-93910: The ability to access the other values of an enum on an enum (e.g. Color.RED.BLUE) has been restored in order to fix a performance regression.

  • gh-93896: Fix asyncio.run() and unittest.IsolatedAsyncioTestCase to always the set event loop as it was done in 哋它亢 3.10 and earlier. Patch by Kumar Aditya.

  • gh-94343: Allow setting the attributes of reprlib.Repr during object initialization

  • gh-94382: Port static types of _multiprocessing module to heap types. Patch by Kumar Aditya.

  • gh-78724: Fix crash in struct.Struct when it was not completely initialized by initializing it in __new__(). Patch by Kumar Aditya.

  • gh-94510: Re-entrant calls to sys.setprofile() and sys.settrace() now raise RuntimeError. Patch by Pablo Galindo.

  • gh-92336: Fix bug where linecache.getline() fails on bad files with UnicodeDecodeError or SyntaxError. It now returns an empty string as per the documentation.

  • gh-94398: Once a asyncio.TaskGroup has started shutting down (i.e., at least one task has failed and the task group has started cancelling the remaining tasks), it should not be possible to add new tasks to the task group.

  • gh-94383: xml.etree: Remove the ElementTree.Element.copy() method of the pure 哋它亢 implementation, deprecated in 哋它亢 3.10, use the copy.copy() function instead. The C implementation of xml.etree has no copy() method, only a __copy__() method. Patch by Victor Stinner.

  • gh-94379: zipimport: Remove find_loader() and find_module() methods, deprecated in 哋它亢 3.10: use the find_spec() method instead. See PEP 451 for the rationale. Patch by Victor Stinner.

  • gh-94352: shlex.split(): Passing None for s argument now raises an exception, rather than reading sys.stdin. The feature was deprecated in 哋它亢 3.9. Patch by Victor Stinner.

  • gh-94318: Strip trailing spaces in pydoc text output.

  • gh-89988: Fix memory leak in pickle.Pickler when looking up dispatch_table. Patch by Kumar Aditya.

  • gh-90016: Deprecate sqlite3 default adapters and converters. Patch by Erlend E. Aasland.

  • gh-94254: Fixed types of struct module to be immutable. Patch by Kumar Aditya.

  • gh-93259: Now raise ValueError when None or an empty string are passed to Distribution.from_name (and other callers).

  • gh-74696: shutil.make_archive() now passes the root_dir argument to custom archivers which support it.

  • gh-94216: The dis module now has the opcodes for pseudo instructions (those which are used by the compiler during code generation but then removed or replaced by real opcodes before the final bytecode is emitted).

  • gh-93096: Removed undocumented 哋它亢 -m codecs. Use 哋它亢 -m unittest test.test_codecs.EncodedFileTest instead.

  • gh-94207: Made _struct.Struct GC-tracked in order to fix a reference leak in the _struct module.

  • gh-93096: Removed undocumented -t argument of 哋它亢 -m base64. Use 哋它亢 -m unittest test.test_base64.LegacyBase64TestCase.test_encodebytes instead.

  • gh-94226: Remove the locale.format() function, deprecated in 哋它亢 3.7: use locale.format_string() instead. Patch by Victor Stinner.

  • gh-94199: Remove the ssl.match_hostname() function. The ssl.match_hostname() was deprecated in 哋它亢 3.7. OpenSSL performs hostname matching since 哋它亢 3.7, 哋它亢 no longer uses the ssl.match_hostname() function. Patch by Victor Stinner.

  • gh-94214: Document the context object used in the venv.EnvBuilder class, and add the new environment's library path to it.

  • gh-94199: Remove the ssl.wrap_socket() function, deprecated in 哋它亢 3.7: instead, create a ssl.SSLContext object and call its ssl.SSLContext.wrap_socket method. Any package that still uses ssl.wrap_socket() is broken and insecure. The function neither sends a SNI TLS extension nor validates server hostname. Code is subject to CWE 295 Improper Certificate Validation. Patch by Victor Stinner.

  • gh-94199: Remove the ssl.RAND_pseudo_bytes() function, deprecated in 哋它亢 3.6: use os.urandom() or ssl.RAND_bytes() instead. Patch by Victor Stinner.

  • gh-94199: hashlib: Remove the pure 哋它亢 implementation of hashlib.pbkdf2_hmac(), deprecated in 哋它亢 3.10. 哋它亢 3.10 and newer requires OpenSSL 1.1.1 (PEP 644): this OpenSSL version provides a C implementation of pbkdf2_hmac() which is faster. Patch by Victor Stinner.

  • gh-94196: gzip: Remove the filename attribute of gzip.GzipFile, deprecated since 哋它亢 2.6, use the name attribute instead. In write mode, the filename attribute added '.gz' file extension if it was not present. Patch by Victor Stinner.

  • gh-94182: run the asyncio.PidfdChildWatcher on the running loop, this allows event loops to run subprocesses when there is no default event loop running on the main thread

  • gh-94169: Remove io.OpenWrapper and _pyio.OpenWrapper, deprecated in 哋它亢 3.10: just use open() instead. The open() (io.open()) function is a built-in function. Since 哋它亢 3.10, _pyio.open() is also a static method. Patch by Victor Stinner.

  • gh-91742: Fix pdb crash after jump caused by a null pointer dereference. Patch by Kumar Aditya.

  • gh-94101: Manual instantiation of ssl.SSLSession objects is no longer allowed as it lead to misconfigured instances that crashed the interpreter when attributes where accessed on them.

  • gh-84753: inspect.iscoroutinefunction(), inspect.isgeneratorfunction(), and inspect.isasyncgenfunction() now properly return True for duck-typed function-like objects like instances of unittest.mock.AsyncMock.

    This makes inspect.iscoroutinefunction() consistent with the behavior of asyncio.iscoroutinefunction(). Patch by Mehdi ABAAKOUK.

  • gh-94028: Fix a regression in the sqlite3 where statement objects were not properly cleared and reset after use in cursor iters. The regression was introduced by PR 27884 in 哋它亢 3.11a1. Patch by Erlend E. Aasland.

  • gh-93973: Add keyword argument all_errors to asyncio.create_connection so that multiple connection errors can be raised as an ExceptionGroup.

  • gh-93963: Officially deprecate from importlib.abc classes moved to importlib.resources.abc.

  • gh-93858: Prevent error when activating venv in nested fish instances.

  • gh-93820: Pickle enum.Flag by name.

  • gh-93847: Fix repr of enum of generic aliases.

  • gh-91404: Revert the re memory leak when a match is terminated by a signal or memory allocation failure as the implemented fix caused a major performance regression.

  • gh-83499: Fix double closing of file description in tempfile.

  • gh-93820: Fixed a regression when copy.copy()-ing enum.Flag with multiple flag members.

  • gh-79512: Fixed names and __module__ value of weakref classes ReferenceType, ProxyType, CallableProxyType. It makes them pickleable.

  • gh-91389: Fix an issue where dis utilities could report missing or incorrect position information in the presence of CACHE entries.

  • gh-93626: Set __future__.annotations to have a None mandatoryRelease to indicate that it is currently 'TBD'.

  • gh-90473: Emscripten and WASI have no home directory and cannot provide PEP 370 user site directory.

  • gh-90494: copy.copy() and copy.deepcopy() now always raise a TypeError if __reduce__() returns a tuple with length 6 instead of silently ignore the 6th item or produce incorrect result.

  • gh-90549: Fix a multiprocessing bug where a global named resource (such as a semaphore) could leak when a child process is spawned (as opposed to forked).

  • gh-93521: Fixed a case where dataclasses would try to add __weakref__ into the __slots__ for a dataclass that specified weakref_slot=True when it was already defined in one of its bases. This resulted in a TypeError upon the new class being created.

  • gh-79579: sqlite3 now correctly detects DML queries with leading comments. Patch by Erlend E. Aasland.

  • gh-93421: Update sqlite3.Cursor.rowcount when a DML statement has run to completion. This fixes the row count for SQL queries like UPDATE ... RETURNING. Patch by Erlend E. Aasland.

  • gh-93475: Expose FICLONE and FICLONERANGE constants in fcntl. Patch by Illia Volochii.

  • gh-93370: Deprecate sqlite3.version and sqlite3.version_info.

  • gh-91810: Suppress writing an XML declaration in open files in ElementTree.write() with encoding='unicode' and xml_declaration=None.

  • gh-91162: Support splitting of unpacked arbitrary-length tuple over TypeVar and TypeVarTuple parameters. For example:

    • A[T, *Ts][*tuple[int, ...]] -> A[int, *tuple[int, ...]]

    • A[*Ts, T][*tuple[int, ...]] -> A[*tuple[int, ...], int]

  • gh-93353: Fix the importlib.resources.as_file() context manager to remove the temporary file if destroyed late during 哋它亢 finalization: keep a local reference to the os.remove() function. Patch by Victor Stinner.

  • gh-83658: Make multiprocessing.Pool raise an exception if maxtasksperchild is not None or a positive int.

  • gh-93312: Add os.PIDFD_NONBLOCK flag to open a file descriptor for a process with os.pidfd_open() in non-blocking mode. Patch by Kumar Aditya.

  • gh-88123: Implement Enum.__contains__ that returns True or False to replace the deprecated behaviour that would sometimes raise a TypeError.

  • gh-93297: Make asyncio task groups prevent child tasks from being GCed

  • gh-85308: Changed argparse.ArgumentParser to use filesystem encoding and error handler instead of default text encoding to read arguments from file (e.g. fromfile_prefix_chars option). This change affects Windows; argument file should be encoded with UTF-8 instead of ANSI Codepage.

  • gh-93156: Accessing the pathlib.PurePath.parents sequence of an absolute path using negative index values produced incorrect results.

  • gh-93162: Add the ability for logging.config.dictConfig() to usefully configure QueueHandler and QueueListener as a pair, and add logging.getHandlerByName() and logging.getHandlerNames() APIs to allow access to handlers by name.

  • gh-93243: The smtpd module was removed per the schedule in PEP 594.

  • gh-92886: Replace assert statements with raise AssertionError() in BaseHandler so that the tested behaviour is maintained running with optimizations (-O).

  • gh-90155: Fix broken asyncio.Semaphore when acquire is cancelled.

  • gh-90817: The locale.resetlocale() function is deprecated and will be removed in 哋它亢 3.13. Use locale.setlocale(locale.LC_ALL, "") instead. Patch by Victor Stinner.

  • gh-91513: Added taskName attribute to logging module for use with asyncio tasks.

  • gh-74696: shutil.make_archive() no longer temporarily changes the current working directory during creation of standard .zip or tar archives.

  • gh-92728: The re.template() function and the corresponding re.TEMPLATE and re.T flags are restored after they were removed in 3.11.0b1, but they are now deprecated, so they might be removed from 哋它亢 3.13.

  • gh-93033: Search in some strings (platform dependent i.e [U+0xFFFF, U+0x0100] on Windows or [U+0xFFFFFFFF, U+0x00010000] on Linux 64-bit) are now up to 10 times faster.

  • gh-89973: Fix re.error raised in fnmatch if the pattern contains a character range with upper bound lower than lower bound (e.g. [c-a]). Now such ranges are interpreted as empty ranges.

  • gh-93044: No longer convert the database argument of sqlite3.connect() to bytes before passing it to the factory.

  • gh-93010: In a very special case, the email package tried to append the nonexistent InvalidHeaderError to the defect list. It should have been InvalidHeaderDefect.

  • gh-92986: Fix ast.unparse() when ImportFrom.level is None

  • gh-92932: Now dis() and get_instructions() handle operand values for instructions prefixed by EXTENDED_ARG_QUICK. Patch by Sam Gross and Donghee Na.

  • gh-92675: Fix venv.ensure_directories() to accept pathlib.Path arguments in addition to str paths. Patch by David Foster.

  • gh-87901: Removed the encoding argument from os.popen() that was added in 3.11b1.

  • gh-91922: Fix function sqlite.connect() and the sqlite.Connection constructor on non-UTF-8 locales. Also, they now support bytes paths non-decodable with the current FS encoding.

  • gh-92869: Added c_time_t to ctypes, which has the same size as the time_t type in C.

  • gh-92839: Fixed crash resulting from calling bisect.insort() or bisect.insort_left() with the key argument not equal to None.

  • gh-90473: subprocess now fails early on Emscripten and WASI platforms to work around missing os.pipe() on WASI.

  • gh-89325: Removed many old deprecated unittest features: TestCase method aliases, undocumented and broken TestCase method assertDictContainsSubset, undocumented TestLoader.loadTestsFromModule parameter use_load_tests, and an underscored alias of the TextTestResult class.

  • gh-92734: Allow multi-element reprs emitted by reprlib to be pretty-printed using configurable indentation.

  • gh-92671: Fixed ast.unparse() for empty tuples in the assignment target context.

  • gh-91581: utcfromtimestamp() no longer attempts to resolve fold in the pure 哋它亢 implementation, since the fold is never 1 in UTC. In addition to being slightly faster in the common case, this also prevents some errors when the timestamp is close to datetime.min. Patch by Paul Ganssle.

  • gh-86388: Removed randrange() functionality deprecated since 哋它亢 3.10. Formerly, randrange(10.0) losslessly converted to randrange(10). Now, it raises a TypeError. Also, the exception raised for non-integral values such as randrange(10.5) or randrange('10') has been changed from ValueError to TypeError.

  • gh-90385: Add pathlib.Path.walk() as an alternative to os.walk().

  • gh-92550: Fix pathlib.Path.rglob() for empty pattern.

  • gh-92591: Allow logging filters to return a logging.LogRecord instance so that filters attached to logging.Handlers can enrich records without side effects on other handlers.

  • gh-92445: Fix a bug in argparse where nargs="*" would raise an error instead of returning an empty list when 0 arguments were supplied if choice was also defined in parser.add_argument.

  • gh-92547: Remove undocumented sqlite3 features deprecated in 哋它亢 3.10:

    • sqlite3.enable_shared_cache()

    • sqlite3.OptimizedUnicode

    Patch by Erlend E. Aasland.

  • gh-92530: Fix an issue that occurred after interrupting threading.Condition.notify().

  • gh-92531: The statistics.median_grouped() function now always return a float. Formerly, it did not convert the input type when for sequences of length one.

  • gh-84131: The pathlib.Path deprecated method link_to has been removed. Use 3.10's hardlink_to() method instead as its semantics are consistent with that of symlink_to().

  • gh-89336: Removed configparser module APIs: the SafeConfigParser class alias, the ParsingError.filename property and parameter, and the ConfigParser.readfp method, all of which were deprecated since 哋它亢 3.2.

  • gh-92391: Add __class_getitem__() to csv.DictReader and csv.DictWriter, allowing them to be parameterized at runtime. Patch by Marc Mueller.

  • gh-91968: Add SO_RTABLE and SO_USER_COOKIE constants to socket.

  • gh-91810: ElementTree method write() and function tostring() now use the text file's encoding ("UTF-8" if not available) instead of locale encoding in XML declaration when encoding="unicode" is specified.

  • gh-81790: os.path.splitdrive() now understands DOS device paths with UNC links (beginning \\?\UNC\). Contributed by Barney Gale.

  • gh-91760: Apply more strict rules for numerical group references and group names in regular expressions. Only sequence of ASCII digits is now accepted as a numerical reference. The group name in bytes patterns and replacement strings can now only contain ASCII letters and digits and underscore.

  • gh-90622: Worker processes for concurrent.futures.ProcessPoolExecutor are no longer spawned on demand (a feature added in 3.9) when the multiprocessing context start method is "fork" as that can lead to deadlocks in the child processes due to a fork happening while threads are running.

  • gh-91577: Move imports in SharedMemory methods to module level so that they can be executed late in 哋它亢 finalization.

  • gh-91581: Remove an unhandled error case in the C implementation of calls to datetime.fromtimestamp with no time zone (i.e. getting a local time from an epoch timestamp). This should have no user-facing effect other than giving a possibly more accurate error message when called with timestamps that fall on 10000-01-01 in the local time. Patch by Paul Ganssle.

  • gh-91539: Improve performance of urllib.request.getproxies_environment when there are many environment variables

  • gh-91524: Speed up the regular expression substitution (functions re.sub() and re.subn() and corresponding re.Pattern methods) for replacement strings containing group references by 2--3 times.

  • gh-91447: Fix findtext in the xml module to only give an empty string when the text attribute is set to None.

  • gh-91456: Deprecate current default auto() behavior: In 3.13 the default will be for for auto() to always return the largest member value incremented by 1, and to raise if incompatible value types are used.

  • bpo-47231: Fixed an issue with inconsistent trailing slashes in tarfile longname directories.

  • bpo-39064: zipfile.ZipFile now raises zipfile.BadZipFile instead of ValueError when reading a corrupt zip file in which the central directory offset is negative.

  • bpo-41287: Fix handling of the doc argument in subclasses of property().

  • gh-90005: ctypes dependency libffi is now detected with pkg-config.

  • bpo-32547: The constructors for DictWriter and DictReader now coerce the fieldnames argument to a list if it is an iterator.

  • bpo-35540: Fix dataclasses.asdict() crash when collections.defaultdict is present in the attributes.

  • bpo-47063: Add an index_pages parameter to support using non-default index page names.

  • bpo-47025: Drop support for bytes on sys.path.

  • bpo-46951: Order the contents of zipapp archives, to make builds more reproducible.

  • bpo-42777: Implement pathlib.Path.is_mount() for Windows paths.

  • bpo-46755: In QueueHandler, clear stack_info from LogRecord to prevent stack trace from being written twice.

  • bpo-45393: Fix the formatting for await x and not x in the operator precedence table when using the help() system.

  • bpo-46642: Improve error message when trying to subclass an instance of typing.TypeVar, typing.ParamSpec, typing.TypeVarTuple, etc. Based on patch by Gregory Beauregard.

  • bpo-46364: Restrict use of sockets instead of pipes for stdin of subprocesses created by asyncio to AIX platform only.

  • bpo-28249: Set doctest.DocTest.lineno to None when an object does not have __doc__.

  • bpo-46197: Fix ensurepip environment isolation for subprocess running pip.

  • bpo-45924: Fix asyncio incorrect traceback when future's exception is raised multiple times. Patch by Kumar Aditya.

  • bpo-45046: Add support of context managers in unittest: methods enterContext() and enterClassContext() of class TestCase, method enterAsyncContext() of class IsolatedAsyncioTestCase and function unittest.enterModuleContext().

  • bpo-44173: Enable fast seeking of uncompressed unencrypted zipfile.ZipExtFile

  • bpo-42627: Fix incorrect parsing of Windows registry proxy settings

  • bpo-42047: Add threading.get_native_id() support for DragonFly BSD. Patch by David Carlier.

  • bpo-14243: The tempfile.NamedTemporaryFile function has a new optional parameter delete_on_close

  • bpo-41246: Give the same callback function for when the overlapped operation is done to the functions recv, recv_into, recvfrom, sendto, send and sendfile inside IocpProactor.

  • bpo-39264: Fixed collections.UserDict.get() to not call __missing__() when a value is not found. This matches the behavior of dict. Patch by Bar Harel.

  • bpo-38693: importlib now uses f-strings internally instead of str.format.

  • bpo-38267: Add timeout parameter to asyncio.loop.shutdown_default_executor(). The default value is None, which means the executor will be given an unlimited amount of time. When called from asyncio.Runner or asyncio.run(), the default timeout is 5 minutes.

  • bpo-34828: sqlite3.Connection.iterdump() now handles databases that use AUTOINCREMENT in one or more tables.

  • bpo-32990: Support reading wave files with the WAVE_FORMAT_EXTENSIBLE format in the wave module.

  • bpo-26253: Allow adjustable compression level for tarfile streams in tarfile.open().

Documentation

  • gh-85525: Remove extra row

  • gh-86404: Deprecated tools make suspicious and rstlint.py are now removed. They have been replaced by sphinx-lint.

  • gh-97741: Fix ! in c domain ref target syntax via a conf.py patch, so it works as intended to disable ref target resolution.

  • gh-96432: Fraction literals now support whitespace around the forward slash, Fraction('2 / 3').

  • gh-96098: Improve discoverability of the higher level concurrent.futures module by providing clearer links from the lower level threading and multiprocessing modules.

  • gh-95957: What's New 3.11 now has instructions for how to provide compiler and linker flags for Tcl/Tk and OpenSSL on RHEL 7 and CentOS 7.

  • gh-95588: Clarified the conflicting advice given in the ast documentation about ast.literal_eval() being "safe" for use on untrusted input while at the same time warning that it can crash the process. The latter statement is true and is deemed unfixable without a large amount of work unsuitable for a bugfix. So we keep the warning and no longer claim that literal_eval is safe.

  • gh-91207: Fix stylesheet not working in Windows CHM htmlhelp docs and add warning that they are deprecated. Contributed by C.A.M. Gerlach.

  • gh-95454: Replaced incorrectly written true/false values in documentation. Patch by Robert O'Shea

  • gh-95451: Update library documentation with availability information on WebAssembly platforms wasm32-emscripten and wasm32-wasi.

  • gh-95415: Use consistent syntax for platform availability. The directive now supports a content body and emits a warning when it encounters an unknown platform.

  • gh-94321: Document the PEP 246 style protocol type sqlite3.PrepareProtocol.

  • gh-86128: Document a limitation in ThreadPoolExecutor where its exit handler is executed before any handlers in atexit.

  • gh-61162: Clarify sqlite3 behavior when 如何使用连接上下文管理器.

  • gh-87260: Align sqlite3 argument specs with the actual implementation.

  • gh-86986: The minimum Sphinx version required to build the documentation is now 3.2.

  • gh-88831: Augmented documentation of asyncio.create_task(). Clarified the need to keep strong references to tasks and added a code snippet detailing how to do this.

  • gh-86438: Clarify that -W and 哋它亢WARNINGS are matched literally and case-insensitively, rather than as regular expressions, in warnings.

  • gh-93031: Update tutorial introduction output to use 3.10+ SyntaxError invalid range.

  • gh-92240: Added release dates for "What's New in 哋它亢 3.X" for 3.0, 3.1, 3.2, 3.8 and 3.10

  • bpo-47161: Document that pathlib.PurePath does not collapse initial double slashes because they denote UNC paths.

  • bpo-40838: Document that inspect.getdoc(), inspect.getmodule(), and inspect.getsourcefile() might return None.

  • bpo-43689: The Differ documentation now also mentions other whitespace characters, which make it harder to understand the diff output.

  • bpo-38056: Overhaul the 错误处理方案 documentation in codecs.

  • bpo-13553: Document tkinter.Tk args.

Tests

  • gh-95027: On Windows, when the 哋它亢 test suite is run with the -jN option, the ANSI code page is now used as the encoding for the stdout temporary file, rather than using UTF-8 which can lead to decoding errors. Patch by Victor Stinner.

  • gh-96624: Fixed the failure of repeated runs of test.test_unittest caused by side effects in test_dotted_but_module_not_loaded.

  • gh-95243: Mitigate the inherent race condition from using find_unused_port() in testSockName() by trying to find an unused port a few times before failing. Patch by Ross Burton.

  • gh-95573: Lib/test/test_asyncio/test_ssl.py exposed a bug in the macOS kernel where intense concurrent load on non-blocking sockets occasionally causes errno.ENOBUFS ("No buffer space available") to be emitted. FB11063974 filed with Apple, in the mean time as a workaround buffer size used in tests on macOS is decreased to avoid intermittent failures. Patch by Fantix King.

  • gh-95280: Fix problem with test_ssl test_get_ciphers on systems that require perfect forward secrecy (PFS) ciphers.

  • gh-95212: Make multiprocessing test case test_shared_memory_recreate parallel-safe.

  • gh-95218: Move tests for importlib.resources into test_importlib.resources.

  • gh-93963: Updated tests to use preferred location for importlib.resources ABCs.

  • gh-94675: Add a regression test for re exponentional slowdown when using rjsmin.

  • gh-91330: Added more tests for dataclasses to cover behavior with data descriptor-based fields.

  • gh-94208: test_ssl is now checking for supported TLS version and protocols in more tests.

  • gh-94315: Tests now check for DAC override capability instead of relying on os.geteuid().

  • gh-54781: Rename test_tk to test_tkinter, and rename test_ttk_guionly to test_ttk. Patch by Victor Stinner.

  • gh-93839: Move Lib/ctypes/test/ to Lib/test/test_ctypes/. Patch by Victor Stinner.

  • gh-93951: In test_bdb.StateTestCase.test_skip, avoid including auxiliary importers.

  • gh-93957: Provide nicer error reporting from subprocesses in test_venv.EnsurePipTest.test_with_pip.

  • gh-93884: Add test cases for PyNumber_ToBase() that take a large number or a non-int object as parameter.

  • gh-93852: test_asyncio, test_logging, test_socket and test_socketserver now create AF_UNIX domains in the current directory to no longer fail with OSError("AF_UNIX path too long") if the temporary directory (the TMPDIR environment variable) is too long. Patch by Victor Stinner.

  • gh-93353: regrtest now checks if a test leaks temporary files or directories if run with -jN option. Patch by Victor Stinner.

  • gh-84461: run_tests.py now handles cross compiling env vars correctly and pass HOSTRUNNER to regression tests.

  • gh-93616: test_modulefinder now creates a temporary directory in ModuleFinderTest.setUp() instead of module scope.

  • gh-93575: Fix issue with test_unicode test_raiseMemError. The test case now use test.support.calcobjsize to calculate size of PyUnicode structs. sys.getsizeof() may return different size when string has UTF-8 memory.

  • gh-90473: WASI does not have a chmod(2) syscall. os.chmod() is now a dummy function on WASI. Skip all tests that depend on working os.chmod().

  • gh-90473: Skip tests on WASI that require symlinks with absolute paths.

  • gh-57539: Increase calendar test coverage for calendar.LocaleTextCalendar.formatweekday().

  • gh-90473: Skip symlink tests on WASI. wasmtime uses openat2(2) with RESOLVE_BENEATH flag, which prevents symlinks with absolute paths.

  • gh-89858: Fix test_embed for out-of-tree builds. Patch by Kumar Aditya.

  • gh-92886: Fixing tests that fail when running with optimizations (-O) in test_imaplib.py.

  • gh-92886: Fixing tests that fail when running with optimizations (-O) in test_zipimport.py

  • gh-92886: Fixing tests that fail when running with optimizations (-O) in test_py_compile.py

  • gh-92886: Fixing tests that fail when running with optimizations (-O) in test_sys_settrace.py.

  • gh-92886: Fixing tests that fail when running with optimizations (-O) in _test_multiprocessing.py

  • gh-92670: Skip test_shutil.TestCopy.test_copyfile_nonexistent_dir test on AIX as the test uses a trailing slash to force the OS consider the path as a directory, but on AIX the trailing slash has no effect and is considered as a file.

  • gh-92514: Remove unused test.support.BasicTestRunner. Patch by Jelle Zijlstra.

  • bpo-47016: Create a GitHub Actions workflow for verifying bundled pip and setuptools. Patch by Illia Volochii and Adam Turner.

Build

  • gh-96761: Fix the build process of clang compiler for _bootstrap_哋它亢 if LTO optimization is applied. Patch by Matthias Görgens and Donghee Na.

  • gh-96883: wasm32-emscripten builds for browsers now include concurrent.futures for asyncio and unittest.mock.

  • gh-85936: C哋它亢 now uses the ThinLTO option as the default policy if the Clang compiler accepts the flag. Patch by Donghee Na.

  • gh-96729: Ensure that Windows releases built with Tools\msi\buildrelease.bat are upgradable to and from official 哋它亢 releases.

  • gh-96269: Shared module targets now depend on new MODULE_DEPS variable, which includes EXPORTSYMS. This fixes a build order issue on unsupported AIX platform.

  • gh-84461: wasm32-emscripten platform no longer builds resource module, getresuid(), getresgid(), and their setters. The APIs are stubs and not functional.

  • gh-95973: Add a new --with-dsymutil configure option to link debug information in macOS. Patch by Pablo Galindo.

  • gh-90536: Use the BOLT post-link optimizer to improve performance, particularly on medium-to-large applications.

  • gh-93744: Remove the configure --with-cxx-main build option: it didn't work for many years. Remove the MAINCC variable from configure and Makefile. Patch by Victor Stinner.

  • gh-94801: Fix a regression in configure script that caused some header checks to ignore custom CPPFLAGS. The regression was introduced in gh-94802.

  • gh-95145: wasm32-wasi builds no longer depend on WASIX's pthread stubs. 哋它亢 now has its own stubbed pthread API.

  • gh-95174: 哋它亢 now detects missing dup function in WASI and works around some missing errno, select, and socket constants.

  • gh-95174: 哋它亢 now skips missing socket functions and methods on WASI. WASI can only create sockets from existing fd / accept and has no netdb.

  • gh-95085: Platforms wasm32-unknown-emscripten and wasm32-unknown-wasi have been promoted to PEP 11 tier 3 platform support.

  • gh-94847: Fixed _decimal module build issue on GCC when compiling with LTO and pydebug. Debug builds no longer force inlining of functions.

  • gh-94841: Fix the possible performance regression of PyObject_Free() compiled with MSVC version 1932.

  • gh-94801: configure now uses custom flags like ZLIB_CFLAGS and ZLIB_LIBS when searching for headers and libraries.

  • gh-94773: deepfreeze.py now supports code object with frozensets that contain incompatible, unsortable types.

  • gh-94682: Build and test with OpenSSL 1.1.1q

  • gh-90005: Dependencies of readline and curses module are now detected in configure script with pkg-config. Only ncurses / ncursesw are detected automatically. The old curses library is not configured automatically. Workaround for missing termcap or tinfo library has been removed.

  • gh-90005: Fix building _ctypes extension without pkg-config.

  • gh-90005: _dbm module dependencies are now detected by configure.

  • gh-94404: makesetup now works around an issue with sed on macOS and uses correct CFLAGS for object files that end up in a shared extension. Module CFLAGS are used before PY_STDMODULE_CFLAGS to avoid clashes with system headers.

  • gh-93939: C extension modules are now built by configure and make instead of distutils and setup.py.

  • gh-93939: The 2to3, idle, and pydoc scripts are now generated and installed by Makefile instead of setup.py.

  • gh-94280: Updated pegen regeneration script on Windows to find and use 哋它亢 3.9 or higher. Prior to this, pegen regeneration already required 3.9 or higher, but the script may have used lower versions of 哋它亢.

  • gh-93584: Address race condition in Makefile when installing a PGO build. All test and install targets now depend on all target.

  • gh-93491: configure now detects and reports PEP 11 support tiers.

  • gh-69093: Fix Modules/Setup.stdlib.in rule for _sqlite3 extension.

  • gh-93207: va_start() with two parameters, like va_start(args, format), is now required to build 哋它亢. va_start() is no longer called with a single parameter. Patch by Kumar Aditya.

  • gh-93202: 哋它亢 now always use the %zu and %zd printf formats to format a size_t or Py_ssize_t number. Building 哋它亢 3.12 requires a C11 compiler, so these printf formats are now always supported. Patch by Victor Stinner.

  • gh-90473: Disable pymalloc and increase stack size on wasm32-wasi.

  • bpo-34449: Drop invalid compiler switch -fPIC for HP aCC on HP-UX. Patch by Michael Osipov.

Windows

  • gh-98360: Fixes multiprocessing spawning child processes on Windows from a virtual environment to ensure that child processes that also use multiprocessing to spawn more children will recognize that they are in a virtual environment.

  • gh-98414: Fix py.exe launcher handling of -V:<company>/ option when default preferences have been set in environment variables or configuration files.

  • gh-97728: Fix possible crashes caused by the use of uninitialized variables when pass invalid arguments in os.system() on Windows and in Windows-specific modules (like winreg).

  • gh-90989: Made 适用于Windows的哋它亢启动器 install per-user by default (unless an all users install already exists), and clarify some text in the installer.

  • gh-97649: The Tools directory is no longer installed on Windows

  • gh-96965: Update libffi to 3.4.3

  • gh-96577: Fixes a potential buffer overrun in msilib.

  • gh-96559: Fixes the Windows launcher not using the compatible interpretation of default tags found in configuration files when no tag was passed to the command.

  • gh-94781: Fix pcbuild.proj to clean previous instances of output files in 哋它亢\deepfreeze and 哋它亢\frozen_modules directories on Windows. Patch by Charlie Zhao.

  • gh-89545: Updates platform code getting the Windows version to use native Windows Management Instrumentation (WMI) queries to determine OS version, type, and architecture.

  • gh-95733: Make certain requirements of the Windows Store package optional to allow installing on earlier updates of Windows.

  • gh-95656: Enable the enable_load_extension() sqlite3 API.

  • gh-95587: Fixes some issues where the Windows installer would incorrectly detect certain features of an existing install when upgrading.

  • gh-94399: Restores the behaviour of 适用于Windows的哋它亢启动器 for /usr/bin/env shebang lines, which will now search PATH for an executable matching the given command. If none is found, the usual search process is used.

  • gh-95445: Fixes the unsuccessful removal of the HTML document directory when uninstalling with Windows msi.

  • gh-95359: Fix 适用于Windows的哋它亢启动器 handling of py.ini commands (it was incorrectly expecting a py_ prefix on keys) and crashes when reading per-user configuration file.

  • gh-95285: Fix 适用于Windows的哋它亢启动器 handling of command lines where it is only passed a short executable name.

  • gh-90844: Allow virtual environments to correctly launch when they have spaces in the path.

  • gh-94772: Fix incorrect handling of shebang lines in py.exe launcher

  • gh-94018: zipfile will now remove trailing spaces from path components when extracting files on Windows.

  • gh-93824: Drag and drop of files onto 哋它亢 files in Windows Explorer has been enabled for Windows ARM64.

  • gh-43414: os.get_terminal_size() now attempts to read the size from any provided handle, rather than only supporting file descriptors 0, 1 and 2.

  • gh-92817: Ensures that py.exe will prefer an active virtual environment over default tags specified with environment variables or through a py.ini file.

  • gh-92984: Explicitly disable incremental linking for non-Debug builds

  • gh-92841: asyncio no longer throws RuntimeError: Event loop is closed on interpreter exit after asynchronous socket activity. Patch by Oleg Iarygin.

  • bpo-46907: Update Windows installer to use SQLite 3.38.4.

  • gh-91061: Accept os.PathLike for the argument to winsound.PlaySound

  • bpo-42658: Support native Windows case-insensitive path comparisons by using LCMapStringEx instead of str.lower() in ntpath.normcase(). Add LCMapStringEx to the _winapi module.

  • bpo-38704: Prevent installation on unsupported Windows versions.

macOS

  • gh-97897: The macOS 13 SDK includes support for the mkfifoat and mknodat system calls. Using the dir_fd option with either os.mkfifo() or os.mknod() could result in a segfault if c哋它亢 is built with the macOS 13 SDK but run on an earlier version of macOS. Prevent this by adding runtime support for detection of these system calls ("weaklinking") as is done for other newer syscalls on macOS.

IDLE

  • gh-97527: Fix a bug in the previous bugfix that caused IDLE to not start when run with 3.10.8, 3.12.0a1, and at least Microsoft 哋它亢 3.10.2288.0 installed without the Lib/test package. 3.11.0 was never affected.

  • gh-65802: Document handling of extensions in Save As dialogs.

  • gh-95191: Include prompts when saving Shell (interactive input and output).

  • gh-95511: Fix the Shell context menu copy-with-prompts bug of copying an extra line when one selects whole lines.

  • gh-95471: In the Edit menu, move Select All and add a new separator.

  • gh-95411: Enable using IDLE's module browser with .pyw files.

  • gh-89610: Add .pyi as a recognized extension for IDLE on macOS. This allows opening stub files by double clicking on them in the Finder.

Tools/Demos

  • gh-68686: Remove ptags and eptags scripts.

  • gh-97681: Remove the Tools/demo/ directory which contained old demo scripts. A copy can be found in the old-demos project. Patch by Victor Stinner.

  • gh-97669: Remove outdated example scripts of the Tools/scripts/ directory. A copy can be found in the old-demos project. Patch by Victor Stinner.

  • gh-95853: The wasm_build.py script now pre-builds Emscripten ports, checks for broken EMSDK versions, and warns about pkg-config env vars.

  • gh-95853: The new tool Tools/wasm/wasm_builder.py automates configure, compile, and test steps for building C哋它亢 on WebAssembly platforms.

  • gh-95731: Fix handling of module docstrings in Tools/i18n/pygettext.py.

  • gh-93939: Add script Tools/scripts/check_modules.py to check and validate builtin and shared extension modules. The script also handles Modules/Setup and will eventually replace setup.py.

  • gh-94538: Fix Argument Clinic output to custom file destinations. Patch by Erlend E. Aasland.

  • gh-94430: Allow parameters named module and self with custom C names in Argument Clinic. Patch by Erlend E. Aasland

  • gh-86087: The Tools/scripts/parseentities.py script used to parse HTML4 entities has been removed.

C API

哋它亢 3.11.0 beta 1

Release date: 2022-05-06

Security

Core and Builtins

  • gh-89519: Chaining classmethod descriptors (introduced in bpo-19072) is deprecated. It can no longer be used to wrap other descriptors such as property(). The core design of this feature was flawed, and it caused a number of downstream problems.

  • gh-92345: pymain_run_哋它亢() now imports readline and rlcompleter before sys.path is extended to include the current working directory of an interactive interpreter. Non-interactive interpreters are not affected.

  • bpo-43857: Improve the AttributeError message when deleting a missing attribute. Patch by Géry Ogam.

  • gh-92245: Make sure that PEP 523 is respected in all cases. In 3.11a7, specialization may have prevented 哋它亢-to-哋它亢 calls respecting PEP 523.

  • gh-92203: Add a closure keyword-only parameter to exec(). It can only be specified when exec-ing a code object that uses free variables. When specified, it must be a tuple, with exactly the number of cell variables referenced by the code object. closure has a default value of None, and it must be None if the code object doesn't refer to any free variables.

  • gh-91173: Disable frozen modules in debug builds. Patch by Kumar Aditya.

  • gh-92114: Improve error message when subscript a type with __class_getitem__ set to None.

  • gh-92112: Fix crash triggered by an evil custom mro() on a metaclass.

  • gh-92063: The PRECALL_METHOD_DESCRIPTOR_FAST_WITH_KEYWORDS instruction now ensures methods are called only on objects of the correct type.

  • gh-92031: Deoptimize statically allocated code objects during Py_FINALIZE() so that future _PyCode_Quicken calls always start with unquickened code.

  • gh-92036: Fix a crash in subinterpreters related to the garbage collector. When a subinterpreter is deleted, untrack all objects tracked by its GC. To prevent a crash in deallocator functions expecting objects to be tracked by the GC, leak a strong reference to these objects on purpose, so they are never deleted and their deallocator functions are not called. Patch by Victor Stinner.

  • gh-92032: The interpreter can now autocomplete soft keywords, as of now match, case, and _ (wildcard pattern) from PEP 634.

  • gh-87999: The warning emitted by the 哋它亢 parser for a numeric literal immediately followed by keyword has been changed from deprecation warning to syntax warning.

  • gh-91869: Fix an issue where specialized opcodes with extended arguments could produce incorrect tracing output or lead to assertion failures.

  • gh-91603: Speed up types.UnionType instantiation. Based on patch provided by Yurii Karabas.

  • gh-89373: If 哋它亢 is built in debug mode, 哋它亢 now ensures that deallocator functions leave the current exception unchanged. Patch by Victor Stinner.

  • gh-91632: Fix a minor memory leak at exit: release the memory of the generic_alias_iterator type. Patch by Donghee Na.

  • gh-81548: Octal escapes with value larger than 0o377 now produce a DeprecationWarning. In a future 哋它亢 version they will be a SyntaxWarning and eventually a SyntaxError.

  • bpo-43950: Use a single compact table for line starts, ends and column offsets. Reduces memory consumption for location info by half

  • gh-91102: Use Argument Clinic for EncodingMap. Patch by Oleg Iarygin.

  • gh-91636: Fixed a crash in a garbage-collection edge-case, in which a PyFunction_Type.tp_clear function could leave a 哋它亢 function object in an inconsistent state.

  • gh-91603: Speed up isinstance() and issubclass() checks for types.UnionType. Patch by Yurii Karabas.

  • gh-91625: Fixed a bug in which adaptive opcodes ignored any preceding EXTENDED_ARGs on specialization failure.

  • gh-78607: The LLTRACE special build now looks for the name __lltrace__ defined in module globals, rather than the name __ltrace__, which had been introduced as a typo.

  • gh-91576: Speed up iteration of ascii strings by 50%. Patch by Kumar Aditya.

  • gh-89279: Improve interpreter performance on Windows by inlining a few specific macros.

  • gh-91502: Add a new _PyFrame_IsEntryFrame() API function, to check if a PyFrameObject is an entry frame. Patch by Pablo Galindo.

  • gh-91266: Refactor the bytearray strip methods strip, lstrip and rstrip to use a common implementation.

  • gh-91479: Replaced the __note__ field of BaseException (added in an earlier version of 3.11) with the final design of PEP 678. Namely, BaseException gets an add_note() method, and its __notes__ field is created when necessary.

  • gh-46055: Speed up right shift of negative integers, by removing unnecessary creation of temporaries. Original patch by Xinhang Xu, reworked by Mark Dickinson.

  • gh-91462: Make the interpreter's low-level tracing (lltrace) feature output more readable by displaying opcode names (rather than just numbers), and by displaying stack contents before each opcode.

  • gh-89455: Fixed an uninitialized bool value in the traceback printing code path that was introduced by the initial bpo-45292 exception groups work.

  • gh-91421: Fix a potential integer overflow in _Py_DecodeUTF8Ex.

  • gh-91428: Add static const char *const _PyOpcode_OpName[256] = {...}; to opcode.h for debug builds to assist in debugging the 哋它亢 interpreter. It is now more convenient to make various forms of debugging output more human-readable by including opcode names rather than just the corresponding decimal digits.

  • bpo-47120: Make POP_JUMP_IF_TRUE, POP_JUMP_IF_FALSE, POP_JUMP_IF_NONE and POP_JUMP_IF_NOT_NONE virtual, mapping to new relative jump opcodes.

  • bpo-45317: Add internal documentation explaining design of new (for 3.11) frame stack.

  • bpo-47197: ctypes used to mishandle void return types, so that for instance a function declared like ctypes.CFUNCTYPE(None, ctypes.c_int) would be called with signature int f(int) instead of void f(int). Wasm targets require function pointers to be called with the correct signatures so this led to crashes. The problem is now fixed.

  • bpo-47120: Make opcodes JUMP_IF_TRUE_OR_POP and JUMP_IF_FALSE_OR_POP relative rather than absolute.

  • bpo-47177: Replace the f_lasti member of the internal _PyInterpreterFrame structure with a prev_instr pointer, which reduces overhead in the main interpreter loop. The f_lasti attribute of 哋它亢-layer frame objects is preserved for backward-compatibility.

  • bpo-46961: Integer mod/remainder operations, including the three-argument form of pow(), now consistently return ints from the global small integer cache when applicable.

  • bpo-46962: Classes and functions that unconditionally declared their docstrings ignoring the --without-doc-strings compilation flag no longer do so.

    The classes affected are ctypes.UnionType, pickle.PickleBuffer, testcapi.RecursingInfinitelyError, and types.GenericAlias.

    The functions affected are 24 methods in ctypes.

    Patch by Oleg Iarygin.

  • bpo-46942: Use Argument Clinic for the types.MethodType constructor. Patch by Oleg Iarygin.

  • bpo-46764: Fix wrapping bound methods with @classmethod

  • bpo-43464: Optimize set.intersection() for non-set arguments.

  • bpo-46721: Optimize set.issuperset() for non-set argument.

  • bpo-46509: Add type-specialized versions of the Py_DECREF(), and use them for float, int, str, bool, and None to avoid pointer-chasing at runtime where types are known at C compile time.

  • bpo-46045: Do not use POSIX semaphores on NetBSD

  • bpo-36819: Fix crashes in built-in encoders with error handlers that return position less or equal than the starting position of non-encodable characters.

  • bpo-34093: marshal.dumps() uses FLAG_REF for all interned strings. This makes output more deterministic and helps reproducible build.

  • bpo-26579: Added object.__getstate__ which provides the default implementation of the __getstate__() method.

    Copying and pickling instances of subclasses of builtin types bytearray, set, frozenset, collections.OrderedDict, collections.deque, weakref.WeakSet, and datetime.tzinfo now copies and pickles instance attributes implemented as slots.

Library

  • gh-87901: Add the encoding parameter to os.popen().

  • gh-90997: Fix an issue where dis utilities may interpret populated inline cache entries as valid instructions.

  • gh-92332: Deprecate typing.Text (removal of the class is currently not planned). Patch by Alex Waygood.

  • Deprecate nested classes in enum definitions becoming members -- in 3.13 they will be normal classes; add member and nonmember functions to allow control over results now.

  • gh-92356: Fixed a performance regression in ctypes function calls.

  • gh-90997: Show the actual named values stored in inline caches when show_caches=True is passed to dis utilities.

  • gh-92301: Prefer close_range() to iterating over procfs for file descriptor closing in subprocess for better performance.

  • gh-67248: Sort the miscellaneous topics in Cmd.do_help()

  • gh-92210: Port socket.__init__ to Argument Clinic. Patch by Cinder.

  • gh-80010: Add support for generalized ISO 8601 parsing to datetime.datetime.fromisoformat(), datetime.date.fromisoformat() and datetime.time.fromisoformat(). Patch by Paul Ganssle.

  • gh-92118: Fix a 3.11 regression in contextmanager(), which caused it to propagate exceptions with incorrect tracebacks.

  • gh-90887: Adding COPYFILE_STAT, COPYFILE_ACL and COPYFILE_XATTR constants for os.fcopyfile() available in macOs.

  • gh-91215: For @dataclass, add weakref_slot. The new parameter defaults to False. If true, and if slots=True, add a slot named "__weakref__", which will allow instances to be weakref'd. Contributed by Eric V. Smith

  • gh-85984: New function os.login_tty() for Unix.

  • gh-92128: Add __class_getitem__() to logging.LoggerAdapter and logging.StreamHandler, allowing them to be parameterized at runtime. Patch by Alex Waygood.

  • gh-92049: Forbid pickling constants re._constants.SUCCESS etc. Previously, pickling did not fail, but the result could not be unpickled.

  • gh-92062: inspect.Parameter now raises ValueError if name is a keyword, in addition to the existing check that it is an identifier.

  • gh-87390: Add an __unpacked__ attribute to types.GenericAlias. Patch by Jelle Zijlstra.

  • gh-88089: Add support for generic typing.NamedTuple.

  • gh-91996: New http.HTTPMethod enum to represent all the available HTTP request methods in a convenient way

  • gh-91984: Modified test strings in test_argparse.py to not contain trailing spaces before end of line.

  • gh-91952: Add encoding="locale" support to TextIOWrapper.reconfigure().

  • gh-91954: Add encoding and errors arguments to subprocess.getoutput() and subprocess.getstatusoutput().

  • bpo-47029: Always close the read end of the pipe used by multiprocessing.Queue after the last write of buffered data to the write end of the pipe to avoid BrokenPipeError at garbage collection and at multiprocessing.Queue.close() calls. Patch by Géry Ogam.

  • gh-91928: Add datetime.UTC alias for datetime.timezone.utc.

    Patch by Kabir Kwatra.

  • gh-68966: The mailcap module is now deprecated and will be removed in 哋它亢 3.13. See PEP 594 for the rationale and the mimetypes module for an alternative. Patch by Victor Stinner.

  • gh-91401: Provide a way to disable subprocess use of vfork() just in case it is ever needed and document the existing mechanism for posix_spawn().

  • gh-64783: Fix signal.NSIG value on FreeBSD to accept signal numbers greater than 32, like signal.SIGRTMIN and signal.SIGRTMAX. Patch by Victor Stinner.

  • gh-91910: Add missing f prefix to f-strings in error messages from the multiprocessing and asyncio modules.

  • gh-91860: Add typing.dataclass_transform(), implementing PEP 681. Patch by Jelle Zijlstra.

  • gh-91832: Add required attribute to argparse.Action repr output.

  • gh-91827: In the tkinter module add method info_patchlevel() which returns the exact version of the Tcl library as a named tuple similar to sys.version_info.

  • gh-84461: Add --enable-wasm-pthreads to enable pthreads support for WASM builds. Emscripten/node no longer has threading enabled by default. Include additional file systems.

  • gh-91821: Fix unstable test_from_tuple test in test_decimal.py.

  • gh-91217: Deprecate the xdrlib module.

  • gh-91217: Deprecate the uu module.

  • gh-91760: More strict rules will be applied for numerical group references and group names in regular expressions. For now, a deprecation warning is emitted for group references and group names which will be errors in future 哋它亢 versions.

  • gh-84461: Add provisional sys._emscripten_info named tuple with build-time and run-time information about Emscripten platform.

  • gh-90623: signal.raise_signal() and os.kill() now check immediately for pending signals. Patch by Victor Stinner.

  • gh-91734: Fix OSS audio support on Solaris.

  • gh-90633: Include the passed value in the exception thrown by typing.assert_never(). Patch by Jelle Zijlstra.

  • gh-91700: Compilation of regular expression containing a conditional expression (?(group)...) now raises an appropriate re.error if the group number refers to not defined group. Previously an internal RuntimeError was raised.

  • gh-91231: Add an optional keyword shutdown_timeout parameter to the multiprocessing.BaseManager constructor. Kill the process if terminate() takes longer than the timeout. Patch by Victor Stinner.

  • gh-91621: Fix typing.get_type_hints() for collections.abc.Callable. Patch by Shantanu Jain.

  • gh-90568: Parsing \N escapes of Unicode Named Character Sequences in a regular expression raises now re.error instead of TypeError.

  • gh-91670: Remove deprecated SO config variable in sysconfig.

  • gh-91217: Deprecate the telnetlib module.

  • gh-91217: Deprecate the sunau module.

  • gh-91217: Deprecate the spwd module.

  • gh-91217: Deprecate the sndhdr module, as well as inline needed functionality for email.mime.MIMEAudio.

  • gh-91616: re module, fix fullmatch() mismatch when using Atomic Grouping or Possessive Quantifiers.

  • gh-91217: Deprecate the 'pipes' module.

  • gh-91217: Deprecate the ossaudiodev module.

  • bpo-47256: re module, limit the maximum capturing group to 1,073,741,823 in 64-bit build, this increases the depth of backtracking.

  • gh-91217: Deprecate the nis module.

  • gh-91595: Fix the comparison of character and integer inside Tools.gdb.lib哋它亢.write_repr(). Patch by Yu Liu.

  • gh-74166: Add option to raise all errors from create_connection() in an ExceptionGroup when it fails to create a connection. The default remains to raise only the last error that had occurred when multiple addresses were tried.

  • gh-91487: Optimize asyncio UDP speed, over 100 times faster when transferring a large file.

  • gh-91575: Update case-insensitive matching in the re module to the latest Unicode version.

  • gh-90622: In concurrent.futures.process.ProcessPoolExecutor disallow the "fork" multiprocessing start method when the new max_tasks_per_child feature is used as the mix of threads+fork can hang the child processes. Default to using the safe "spawn" start method in that circumstance if no mp_context was supplied.

  • gh-89022: In sqlite3, SQLITE_MISUSE result codes are now mapped to InterfaceError instead of ProgrammingError. Also, more accurate exceptions are raised when binding parameters fail. Patch by Erlend E. Aasland.

  • gh-91526: Stop calling os.device_encoding(file.fileno()) in TextIOWrapper. It was complex, never documented, and didn't work for most cases. (Patch by Inada Naoki.)

  • gh-88116: Change the frame-related functions in the inspect module to return a regular object (that is backwards compatible with the old tuple-like interface) that include the extended PEP 657 position information (end line number, column and end column). The affected functions are: inspect.getframeinfo(), inspect.getouterframes(), inspect.getinnerframes(), inspect.stack() and inspect.trace(). Patch by Pablo Galindo.

  • gh-69093: Add indexing and slicing support to sqlite3.Blob. Patch by Aviv Palivoda and Erlend E. Aasland.

  • gh-69093: Add context manager support to sqlite3.Blob. Patch by Aviv Palivoda and Erlend E. Aasland.

  • gh-91217: Deprecate nntplib.

  • gh-91217: Deprecate msilib.

  • gh-91404: Improve the performance of re matching by using computed gotos (or "threaded code") on supported platforms and removing expensive pointer indirections.

  • gh-91217: Deprecate the imghdr module.

  • gh-91217: Deprecate the crypt module.

  • gh-91276: Make space for longer opcodes in dis output.

  • bpo-47000: Make TextIOWrapper uses locale encoding when encoding="locale" is specified even in UTF-8 mode.

  • gh-91230: warnings.catch_warnings() now accepts arguments for warnings.simplefilter(), providing a more concise way to locally ignore warnings or convert them to errors.

  • gh-91217: Deprecate the chunk module.

  • Add the TCP_CONNECTION_INFO option (available on macOS) to socket.

  • bpo-47260: Fix os.closerange() potentially being a no-op in a Linux seccomp sandbox.

  • bpo-47087: Implement typing.Required and typing.NotRequired (PEP 655). Patch by David Foster and Jelle Zijlstra.

  • bpo-47061: Deprecate cgi and cgitb.

  • bpo-47061: Deprecate audioop.

  • bpo-47000: Add locale.getencoding() to get the current locale encoding. It is similar to locale.getpreferredencoding(False) but ignores the 哋它亢 UTF-8 Mode.

  • bpo-42012: Add wsgiref.types, containing WSGI-specific types for static type checking.

  • bpo-47227: Suppress expression chaining for more re parsing errors.

  • bpo-47211: Remove undocumented and never working function re.template() and flag re.TEMPLATE. This was later reverted in 3.11.0b2 and deprecated instead.

  • bpo-47135: decimal.localcontext() now accepts context attributes via keyword arguments

  • bpo-43323: Fix errors in the email module if the charset itself contains undecodable/unencodable characters.

  • bpo-46841: Disassembly of quickened code.

  • bpo-46681: Forward gzip.compress() compresslevel to zlib.

  • bpo-45100: Add typing.get_overloads() and typing.clear_overloads(). Patch by Jelle Zijlstra.

  • bpo-44807: typing.Protocol no longer silently replaces __init__() methods defined on subclasses. Patch by Adrian Garcia Badaracco.

  • bpo-46787: Fix concurrent.futures.ProcessPoolExecutor exception memory leak

  • bpo-46720: Add support for path-like objects to multiprocessing.set_executable() for Windows to be on a par with Unix-like systems. Patch by Géry Ogam.

  • bpo-46696: Add SO_INCOMING_CPU constant to socket.

  • bpo-46053: Fix OSS audio support on NetBSD.

  • bpo-45639: image/avif and image/webp were added to mimetypes.

  • bpo-46285: Add command-line option -p/--protocol to module http.server which specifies the HTTP version to which the server is conformant (HTTP/1.1 conformant servers can now be run from the command-line interface of module http.server). Patch by Géry Ogam.

  • bpo-44791: Accept ellipsis as the last argument of typing.Concatenate.

  • bpo-46547: Remove variables leaking into pydoc.Helper class namespace.

  • bpo-46415: Fix ipaddress.ip_{address,interface,network} raising TypeError instead of ValueError if given invalid tuple as address parameter.

  • bpo-46075: CookieJar with DefaultCookiePolicy now can process cookies from localhost with domain=localhost explicitly specified in Set-Cookie header.

  • bpo-45995: Add a "z" option to the string formatting specification that coerces negative zero floating-point values to positive zero after rounding to the format precision. Contributed by John Belmonte.

  • bpo-26175: Fully implement the io.BufferedIOBase or io.TextIOBase interface for tempfile.SpooledTemporaryFile objects. This lets them work correctly with higher-level layers (like compression modules). Patch by Carey Metcalfe.

  • bpo-45138: Fix a regression in the sqlite3 trace callback where bound parameters were not expanded in the passed statement string. The regression was introduced in 哋它亢 3.10 by bpo-40318. Patch by Erlend E. Aasland.

  • bpo-44863: Allow TypedDict subclasses to also include Generic as a base class in class based syntax. Thereby allowing the user to define a generic TypedDict, just like a user-defined generic but with TypedDict semantics.

  • bpo-44587: Fix BooleanOptionalAction to not automatically add a default string. If a default string is desired, use a formatter to add it.

  • bpo-43827: All positional-or-keyword parameters to ABCMeta.__new__ are now positional-only to avoid conflicts with keyword arguments to be passed to __init_subclass__().

  • bpo-43218: Prevent creation of a venv whose path contains the PATH separator. This could affect the usage of the activate script. Patch by Dustin Rodrigues.

  • bpo-38435: Add a process_group parameter to subprocess.Popen to help move more things off of the unsafe preexec_fn parameter.

  • bpo-42066: Fix cookies getting sorted in CookieJar.__iter__() which is an extra behavior and not mentioned in RFC 2965 or Netscape cookie protocol. Now the cookies in CookieJar follows the order of the Set-Cookie header. Patch by Iman Kermani.

  • bpo-40617: Add create_window_function() to sqlite3.Connection for creating aggregate window functions. Patch by Erlend E. Aasland.

  • bpo-40676: Convert csv to use Argument Clinic for csv.field_size_limit(), csv.get_dialect(), csv.unregister_dialect() and csv.list_dialects().

  • bpo-39716: Raise an ArgumentError when the same subparser name is added twice to an argparse.ArgumentParser. This is consistent with the (default) behavior when the same option string is added twice to an ArgumentParser.

  • bpo-36073: Raise ProgrammingError instead of segfaulting on recursive usage of cursors in sqlite3 converters. Patch by Sergey Fedoseev.

  • bpo-34975: Adds a start_tls() method to StreamWriter, which upgrades the connection with TLS using the given SSLContext.

  • bpo-22276: Path methods glob() and rglob() return only directories if pattern ends with a pathname components separator (/ or sep). Patch by Eisuke Kawashima.

  • bpo-24905: Add blobopen() to sqlite3.Connection. sqlite3.Blob allows incremental I/O operations on blobs. Patch by Aviv Palivoda and Erlend E. Aasland.

Documentation

Tests

  • gh-92169: Use warnings_helper.import_deprecated() to import deprecated modules uniformly in tests. Patch by Hugo van Kemenade.

  • gh-84461: When multiprocessing is enabled, libregrtest can now use a 哋它亢 executable other than sys.executable via the --哋它亢 flag.

  • gh-91904: Fix initialization of 哋它亢REGRTEST_UNICODE_GUARD which prevented running regression tests on non-UTF-8 locale.

  • gh-91752: Added @requires_zlib to test.test_tools.test_freeze.TestFreeze.

  • gh-91607: Fix test_concurrent_futures to test the correct multiprocessing start method context in several cases where the test logic mixed this up.

  • bpo-40280: Threading tests are now skipped on WASM targets without pthread support.

  • bpo-47109: Test for ctypes.macholib.dyld, ctypes.macholib.dylib, and ctypes.macholib.framework are brought from manual pre-unittest times to ctypes.test location and structure. Patch by Oleg Iarygin.

  • bpo-29890: Add tests for ipaddress.IPv4Interface and ipaddress.IPv6Interface construction with tuple arguments. Original patch and tests by louisom.

Build

  • gh-89452: gdbm-compat is now preferred over ndbm if both are available on the system. This allows avoiding the problematic ndbm.h on macOS.

  • gh-91731: 哋它亢 is now built with -std=c11 compiler option, rather than -std=c99. Patch by Victor Stinner.

  • bpo-47152: Add script and make target for generating sre_constants.h.

  • bpo-47103: Windows PGInstrument builds now copy a required DLL into the output directory, making it easier to run the profile stage of a PGO build.

Windows

  • bpo-46907: Update Windows installer to use SQLite 3.38.3.

  • bpo-47239: Fixed --list and --list-paths output for 适用于Windows的哋它亢启动器 when used in an active virtual environment.

  • bpo-46907: Update Windows installer to use SQLite 3.38.2.

  • bpo-46785: Fix race condition between os.stat() and unlinking a file on Windows, by using errors codes returned by FindFirstFileW() when appropriate in win32_xstat_impl.

  • bpo-40859: Update Windows build to use xz-5.2.5

macOS

  • bpo-46907: Update macOS installer to SQLite 3.38.4.

Tools/Demos

  • gh-91583: Fix regression in the code generated by Argument Clinic for functions with the defining_class parameter.

  • gh-91575: Add script Tools/scripts/generate_re_casefix.py and the make target regen-re for generating additional data for case-insensitive matching according to the current Unicode version.

  • gh-91551: Remove the ancient Pynche color editor. It has moved to https://gitlab.com/warsaw/pynche

C API

  • gh-88279: Deprecate the C functions: PySys_SetArgv(), PySys_SetArgvEx(), PySys_SetPath(). Patch by Victor Stinner.

  • gh-92154: Added the PyCode_GetCode() function. This function does the equivalent of the 哋它亢 code getattr(code_object, 'co_code').

  • gh-92173: Fix the closure argument to PyEval_EvalCodeEx().

  • gh-91320: Fix C++ compiler warnings about "old-style cast" (g++ -Wold-style-cast) in the 哋它亢 C API. Use C++ reinterpret_cast<> and static_cast<> casts when the 哋它亢 C API is used in C++. Patch by Victor Stinner.

  • gh-80527: Mark functions as deprecated by PEP 623: PyUnicode_AS_DATA(), PyUnicode_AS_UNICODE(), PyUnicode_GET_DATA_SIZE(), PyUnicode_GET_SIZE(). Patch by Victor Stinner.

  • gh-91768: Py_REFCNT(), Py_TYPE(), Py_SIZE() and Py_IS_TYPE() functions argument type is now PyObject*, rather than const PyObject*. Patch by Victor Stinner.

  • gh-91020: Add PyBytes_Type.tp_alloc to initialize PyBytesObject.ob_shash for bytes subclasses.

  • bpo-40421: Add PyFrame_GetLasti C-API function to access frame object's f_lasti attribute safely from C code.

  • bpo-35134: Remove the Include/code.h header file. C extensions should only include the main <哋它亢.h> header file. Patch by Victor Stinner.

  • bpo-47169: PyOS_CheckStack() is now exported in the Stable ABI on Windows.

  • bpo-47169: PyThread_get_thread_native_id() is excluded from the stable ABI on platforms where it doesn't exist (like Solaris).

  • bpo-46343: Added PyErr_GetHandledException() and PyErr_SetHandledException() as simpler alternatives to PyErr_GetExcInfo() and PyErr_SetExcInfo().

    They are included in the stable ABI.

哋它亢 3.11.0 alpha 7

Release date: 2022-04-05

Core and Builtins

  • bpo-47212: Raise IndentationError instead of SyntaxError for a bare except with no following indent. Improve SyntaxError locations for an un-parenthesized generator used as arguments. Patch by Matthieu Dartiailh.

  • bpo-47186: Replace JUMP_IF_NOT_EG_MATCH by CHECK_EG_MATCH + jump.

  • bpo-47176: Emscripten builds cannot handle signals in the usual way due to platform limitations. 哋它亢 can now handle signals. To use, set Module.Py_EmscriptenSignalBuffer to be a single byte SharedArrayBuffer and set Py_EMSCRIPTEN_SIGNAL_HANDLING to 1. Writing a number into the SharedArrayBuffer will cause the corresponding signal to be raised into the 哋它亢 thread.

  • bpo-47186: Replace JUMP_IF_NOT_EXC_MATCH by CHECK_EXC_MATCH + jump.

  • bpo-47120: Replace the absolute jump opcode JUMP_NO_INTERRUPT by the relative JUMP_BACKWARD_NO_INTERRUPT.

  • bpo-46841: Avoid unnecessary allocations when comparing code objects.

  • bpo-47182: Fix a crash when using a named unicode character like "\N{digit nine}" after the main interpreter has been initialized a second time.

  • bpo-47162: WebAssembly cannot deal with bad function pointer casts (different count or types of arguments). 哋它亢 can now use call trampolines to mitigate the problem. Define PY_CALL_TRAMPOLINE to enable call trampolines.

  • bpo-46775: Some Windows system error codes(>= 10000) are now mapped into the correct errno and may now raise a subclass of OSError. Patch by Donghee Na.

  • bpo-47129: Improve error messages in f-string syntax errors concerning empty expressions.

  • bpo-47117: Fix a crash if we fail to decode characters in interactive mode if the tokenizer buffers are uninitialized. Patch by Pablo Galindo.

  • bpo-47127: Speed up calls to c functions with keyword arguments by 25% with specialization. Patch by Kumar Aditya.

  • bpo-47120: Replaced JUMP_ABSOLUTE by the relative jump JUMP_BACKWARD.

  • bpo-42197: PyFrame_FastToLocalsWithError() and PyFrame_LocalsToFast() are no longer called during profiling nor tracing. C code can access the f_locals attribute of PyFrameObject by calling PyFrame_GetLocals().

  • bpo-47070: Improve performance of array_inplace_repeat by reducing the number of invocations of memcpy. Refactor the repeat and inplace repeat methods of array, bytes, bytearray and unicodeobject to use the common _PyBytes_Repeat.

  • bpo-47053: Reduce de-optimization in the specialized BINARY_OP_INPLACE_ADD_UNICODE opcode.

  • bpo-47045: Remove the f_state field from the _PyInterpreterFrame struct. Add the owner field to the _PyInterpreterFrame struct to make ownership explicit to simplify clearing and deallocing frames and generators.

  • bpo-46968: Check for the existence of the "sys/auxv.h" header in faulthandler to avoid compilation problems in systems where this header doesn't exist. Patch by Pablo Galindo

  • bpo-46329: Use low bit of LOAD_GLOBAL to indicate whether to push a NULL before the global. Helps streamline the call sequence a bit.

  • bpo-46841: Quicken bytecode in-place by storing it as part of the corresponding PyCodeObject.

  • bpo-47012: Speed up iteration of bytes and bytearray by 30%. Patch by Kumar Aditya.

  • bpo-47009: Improved the performance of list.append() and list comprehensions by optimizing for the common case, where no resize is needed. Patch by Dennis Sweeney.

  • bpo-47005: Improve performance of bytearray_repeat and bytearray_irepeat by reducing the number of invocations of memcpy.

  • bpo-46829: Deprecate passing a message into asyncio.Future.cancel() and asyncio.Task.cancel()

  • bpo-46993: Speed up bytearray creation from list and tuple by 40%. Patch by Kumar Aditya.

  • bpo-39829: Removed the __len__() call when initializing a list and moved initializing to list_extend. Patch by Jeremiah Pascual.

  • bpo-46944: Speed up throwing exception in generator with METH_FASTCALL calling convention. Patch by Kumar Aditya.

  • bpo-46841: Modify STORE_SUBSCR to use an inline cache entry (rather than its oparg) as an adaptive counter.

  • bpo-46841: Use inline caching for PRECALL and CALL, and remove the internal machinery for managing the (now unused) non-inline caches.

  • bpo-46881: Statically allocate and initialize the latin1 characters.

  • bpo-46838: Improve syntax errors for incorrect function definitions. Patch by Pablo Galindo

  • bpo-43721: Fix docstrings of getter, setter, and deleter to clarify that they create a new copy of the property.

  • bpo-43224: Make grammar changes required for PEP 646.

Library

  • bpo-47208: Allow vendors to override CTYPES_MAX_ARGCOUNT.

  • bpo-23689: re module: fix memory leak when a match is terminated by a signal or memory allocation failure. Patch by Ma Lin.

  • bpo-47167: Allow overriding a future compliance check in asyncio.Task.

  • bpo-47151: When subprocess tries to use vfork, it now falls back to fork if vfork returns an error. This allows use in situations where vfork isn't allowed by the OS kernel.

  • bpo-47152: Convert the re module into a package. Deprecate modules sre_compile, sre_constants and sre_parse.

  • bpo-4833: Add ZipFile.mkdir()

  • bpo-27929: Fix asyncio.loop.sock_connect() to only resolve names for socket.AF_INET or socket.AF_INET6 families. Resolution may not make sense for other families, like socket.AF_BLUETOOTH and socket.AF_UNIX.

  • bpo-14265: Adds the fully qualified test name to unittest output

  • bpo-47061: Deprecate the aifc module.

  • bpo-39622: Handle Ctrl+C in asyncio programs to interrupt the main task.

  • bpo-47101: hashlib.algorithms_available now lists only algorithms that are provided by activated crypto providers on OpenSSL 3.0. Legacy algorithms are not listed unless the legacy provider has been loaded into the default OSSL context.

  • bpo-47099: All URLError exception messages raised in urllib.request.URLopener now contain a colon between ftp error and the rest of the message. Previously, open_ftp() missed the colon. Patch by Oleg Iarygin.

  • bpo-47099: Exception chaining is changed from Exception.with_traceback()/sys.exc_info() to PEP 3134. Patch by Oleg Iarygin.

  • bpo-47095: hashlib's internal _blake2 module now prefers libb2 from https://www.blake2.net/ over 哋它亢's vendored copy of blake2.

  • bpo-47098: The Keccak Code Package for hashlib's internal _sha3 module has been replaced with tiny_sha3. The module is used as fallback when 哋它亢 is built without OpenSSL.

  • bpo-47088: Implement typing.LiteralString, part of PEP 675. Patch by Jelle Zijlstra.

  • bpo-42885: Optimize re.search(), re.split(), re.findall(), re.finditer() and re.sub() for regular expressions starting with \A or ^.

  • bpo-23691: Protect the re.finditer() iterator from re-entering.

  • bpo-47067: Optimize calling GenericAlias objects by using PEP 590 vectorcall and by replacing PyObject_SetAttrString with PyObject_SetAttr.

  • bpo-28080: Add the metadata_encoding parameter in the zipfile.ZipFile constructor and the --metadata-encoding option in the zipfile CLI to allow reading zipfiles using non-standard codecs to encode the filenames within the archive.

  • bpo-47000: Make io.text_encoding() returns "utf-8" when UTF-8 mode is enabled.

  • bpo-42369: Fix thread safety of zipfile._SharedFile.tell() to avoid a "zipfile.BadZipFile: Bad CRC-32 for file" exception when reading a ZipFile from multiple threads.

  • bpo-38256: Fix binascii.crc32() when it is compiled to use zlib'c crc32 to work properly on inputs 4+GiB in length instead of returning the wrong result. The workaround prior to this was to always feed the function data in increments smaller than 4GiB or to just call the zlib module function.

    We also have binascii.crc32() release the GIL when computing on larger inputs as zlib.crc32() and hashlib do.

    This also boosts performance on Windows as it now uses the zlib crc32 implementation for binascii.crc32() for a 2-3x speedup.

    That the stdlib has a crc32 API in two modules is a known historical oddity. This moves us closer to a single implementation behind them.

  • bpo-47066: Global inline flags (e.g. (?i)) can now only be used at the start of the regular expressions. Using them not at the start of expression was deprecated since 哋它亢 3.6.

  • bpo-39394: A warning about inline flags not at the start of the regular expression now contains the position of the flag.

  • bpo-433030: Add support of atomic grouping ((?>...)) and possessive quantifiers (*+, ++, ?+, {m,n}+) in regular expressions.

  • bpo-47062: Implement asyncio.Runner context manager.

  • bpo-46382: dataclass() slots=True now correctly omits slots already defined in base classes. Patch by Arie Bovenberg.

  • bpo-47057: Use FASTCALL convention for FutureIter.throw()

  • bpo-47061: Deprecate the various modules listed by PEP 594:

    aifc, asynchat, asyncore, audioop, cgi, cgitb, chunk, crypt, imghdr, msilib, nntplib, nis, ossaudiodev, pipes, smtpd, sndhdr, spwd, sunau, telnetlib, uu, xdrlib

  • bpo-34790: Remove passing coroutine objects to asyncio.wait().

  • bpo-47039: Normalize repr() of asyncio future and task objects.

  • bpo-2604: Fix bug where doctests using globals would fail when run multiple times.

  • bpo-45150: Add hashlib.file_digest() helper for efficient hashing of file object.

  • bpo-34861: Made cumtime the default sorting key for cProfile

  • bpo-45997: Fix asyncio.Semaphore re-aquiring FIFO order.

  • bpo-47022: The asynchat, asyncore and smtpd modules have been deprecated since at least 哋它亢 3.6. Their documentation and deprecation warnings and have now been updated to note they will removed in 哋它亢 3.12 (PEP 594).

  • bpo-43253: Fix a crash when closing transports where the underlying socket handle is already invalid on the Proactor event loop.

  • bpo-40280: select.select() now passes NULL to select for each empty fdset.

  • bpo-47004: Apply bugfixes from importlib_metadata 4.11.3, including bugfix for EntryPoint.extras, which was returning match objects and not the extras strings.

  • bpo-46998: Allow subclassing of typing.Any. Patch by Shantanu Jain.

  • bpo-46995: Deprecate missing asyncio.Task.set_name() for third-party task implementations, schedule making it mandatory in 哋它亢 3.13.

  • bpo-46994: Accept explicit contextvars.Context in asyncio.create_task() and asyncio.loop.create_task().

  • bpo-46981: typing.get_args(typing.Tuple[()]) now returns () instead of ((),).

  • bpo-46968: Add os.sysconf_names['SC_MINSIGSTKSZ'].

  • bpo-46985: Upgrade pip wheel bundled with ensurepip (pip 22.0.4)

  • bpo-46968: faulthandler: On Linux 5.14 and newer, dynamically determine size of signal handler stack size C哋它亢 allocates using getauxval(AT_MINSIGSTKSZ). This changes allows for 哋它亢 extension's request to Linux kernel to use AMX_TILE instruction set on Sapphire Rapids Xeon processor to succeed, unblocking use of the ISA in frameworks.

  • bpo-46917: The math.nan value is now always available. Patch by Victor Stinner.

  • bpo-46955: Expose asyncio.base_events.Server as asyncio.Server. Patch by Stefan Zabka.

  • bpo-23325: The signal module no longer assumes that SIG_IGN and SIG_DFL are small int singletons.

  • bpo-46932: Update bundled libexpat to 2.4.7

  • bpo-46933: The pwd module is now optional. os.path.expanduser() returns the path when the pwd module is not available.

  • bpo-40059: PEP 680, the tomllib module. Adds support for parsing TOML.

  • bpo-464471: asyncio.timeout() and asyncio.timeout_at() context managers added. Patch by Tin Tvrtković and Andrew Svetlov.

  • bpo-46805: Added raw datagram socket functions for asyncio: sock_sendto(), sock_recvfrom() and sock_recvfrom_into().

  • bpo-46644: No longer require valid typeforms to be callable. This allows typing.Annotated to wrap typing.ParamSpecArgs and dataclasses.InitVar. Patch by Gregory Beauregard.

  • bpo-46581: Brings ParamSpec propagation for GenericAlias in line with Concatenate (and others).

  • bpo-45413: Define posix_venv and nt_venv sysconfig installation schemes to be used for bootstrapping new virtual environments. Add venv sysconfig installation scheme to get the appropriate one of the above. The schemes are identical to the pre-existing posix_prefix and nt install schemes. The venv module now uses the venv scheme to create new virtual environments instead of hardcoding the paths depending only on the platform. Downstream 哋它亢 distributors customizing the posix_prefix or nt install scheme in a way that is not compatible with the install scheme used in virtual environments are encouraged not to customize the venv schemes. When 哋它亢 itself runs in a virtual environment, sysconfig.get_default_scheme() and sysconfig.get_preferred_scheme() with key="prefix" returns venv.

  • bpo-43224: Implement support for PEP 646 in typing.py.

  • bpo-43224: Allow unpacking types.GenericAlias objects, e.g. *tuple[int, str].

  • bpo-46557: Warnings captured by the logging module are now logged without a format string to prevent systems that group logs by the msg argument from grouping captured warnings together.

  • bpo-41370: typing.get_type_hints() now supports evaluating strings as forward references in PEP 585 generic aliases.

  • bpo-46607: Add DeprecationWarning to LegacyInterpolation, deprecated in the docstring since 哋它亢 3.2. Will be removed in 哋它亢 3.13. Use BasicInterpolation or ExtendedInterpolation instead.

  • bpo-26120: pydoc now excludes __future__ imports from the module's data items.

  • bpo-46480: Add typing.assert_type(). Patch by Jelle Zijlstra.

  • bpo-46421: Fix a unittest issue where if the command was invoked as 哋它亢 -m unittest and the filename(s) began with a dot (.), a ValueError is returned.

  • bpo-46245: Add optional parameter dir_fd in shutil.rmtree().

  • bpo-22859: unittest.TestProgram.usageExit() is marked as deprecated, to be removed in 哋它亢 3.13.

  • bpo-46170: Improve the error message when you try to subclass an instance of typing.NewType.

  • bpo-40296: Fix supporting generic aliases in pydoc.

  • bpo-20392: Fix inconsistency with uppercase file extensions in MimeTypes.guess_type(). Patch by Kumar Aditya.

  • bpo-46030: Add LOCAL_CREDS, LOCAL_CREDS_PERSISTENT and SCM_CREDS2 FreeBSD constants to the socket module.

  • bpo-44439: Fix .write() method of a member file in ZipFile, when the input data is an object that supports the buffer protocol, the file length may be wrong.

  • bpo-45171: Fix handling of the stacklevel argument to logging functions in the logging module so that it is consistent across all logging functions and, as advertised, similar to the stacklevel argument used in warn().

  • bpo-24959: Fix bug where unittest sometimes drops frames from tracebacks of exceptions raised in tests.

  • bpo-44859: Raise more accurate and PEP 249 compatible exceptions in sqlite3.

  • bpo-44493: Add missing terminated NUL in sockaddr_un's length

    This was potentially observable when using non-abstract AF_UNIX datagram sockets to processes written in another programming language.

  • bpo-41930: Add serialize() and deserialize() support to sqlite3. Patch by Erlend E. Aasland.

  • bpo-33178: Added ctypes.BigEndianUnion and ctypes.LittleEndianUnion classes, as originally documented in the library docs but not yet implemented.

  • bpo-43352: Add an Barrier object in synchronization primitives of asyncio Lib in order to be consistent with Barrier from threading and multiprocessing libs*

  • bpo-35859: re module, fix a few bugs about capturing group. In rare cases, capturing group gets an incorrect string. Patch by Ma Lin.

Documentation

  • bpo-45099: Document internal asyncio API.

  • bpo-47126: Update PEP URLs to PEP 676's new canonical form.

  • bpo-47040: Clarified the old 哋它亢 versions compatibility note of binascii.crc32() / zlib.adler32() / zlib.crc32() functions.

  • bpo-46033: Clarify for statement execution in its doc.

  • bpo-45790: Adjust inaccurate phrasing in 自定义扩展类型：教程 about the ob_base field and the macros used to access its contents.

  • bpo-42340: Document that in some circumstances KeyboardInterrupt may cause the code to enter an inconsistent state. Provided a sample workaround to avoid it if needed.

  • bpo-41233: Link the errnos referenced in Doc/library/exceptions.rst to their respective section in Doc/library/errno.rst, and vice versa. Previously this was only done for EINTR and InterruptedError. Patch by Yan "yyyyyyyan" Orestes.

Tests

Build

  • bpo-40280: Add configure option --enable-wasm-dynamic-linking to enable dlopen and MAIN_MODULE / SIDE_MODULE on wasm32-emscripten.

  • bpo-46023: makesetup now detects and skips all duplicated module definitions. The first entry wins.

  • bpo-40280: Add SOABI wasm32-emscripten for Emscripten and wasm32-wasi for WASI on 32bit WASM as well as wasm64 counter parts.

  • bpo-47032: Ensure Windows install builds fail correctly with a non-zero exit code when part of the build fails.

  • bpo-47024: Update OpenSSL to 1.1.1n for macOS installers and all Windows builds.

  • bpo-46996: The tkinter package now requires Tcl/Tk version 8.5.12 or newer.

  • bpo-46973: Add regen-configure make target to regenerate configure script with Christian's container image quay.io/tiran/c哋它亢_autoconf:269.

  • bpo-46917: Building 哋它亢 now requires support of IEEE 754 floating-point numbers. Patch by Victor Stinner.

  • bpo-45774: configure now verifies that all SQLite C APIs needed for the sqlite3 extension module are found.

Windows

  • bpo-47194: Update zlib to v1.2.12 to resolve CVE 2018-25032.

  • bpo-47171: Enables installing the py.exe launcher on Windows ARM64.

  • bpo-46566: Upgraded 适用于Windows的哋它亢启动器 to support a new -V:company/tag argument for full PEP 514 support and to detect ARM64 installs. The -64 suffix on arguments is deprecated, but still selects any non-32-bit install. Setting PYLAUNCHER_ALLOW_INSTALL and specifying a version that is not installed will attempt to install the requested version from the Microsoft Store.

  • bpo-47086: The installer for Windows now includes documentation as loose HTML files rather than a single compiled .chm file.

  • bpo-46907: Update Windows installer to use SQLite 3.38.1.

  • bpo-44549: Update bzip2 to 1.0.8 in Windows builds to mitigate CVE 2016-3189 and CVE 2019-12900.

  • bpo-46948: Prevent CVE 2022-26488 by ensuring the Add to PATH option in the Windows installer uses the correct path when being repaired.

macOS

  • bpo-46890: Fix a regression in the setting of sys._base_executable in framework builds, and thereby fix a regression in venv virtual environments with such builds.

  • bpo-46907: Update macOS installer to SQLite 3.38.1.

Tools/Demos

  • bpo-40280: Replace Emscripten's limited shell with Katie Bell's browser-ui REPL from 哋它亢-wasm project.

C API

  • bpo-40421: Add PyFrame_GetBuiltins, PyFrame_GetGenerator and PyFrame_GetGlobals C-API functions to access frame object attributes safely from C code.

  • bpo-46850: Move the private _PyFrameEvalFunction type, and private _PyInterpreterState_GetEvalFrameFunc() and _PyInterpreterState_SetEvalFrameFunc() functions to the internal C API. The _PyFrameEvalFunction callback function type now uses the _PyInterpreterFrame type which is part of the internal C API. Patch by Victor Stinner.

  • bpo-46850: Move the private undocumented _PyEval_EvalFrameDefault() function to the internal C API. The function now uses the _PyInterpreterFrame type which is part of the internal C API. Patch by Victor Stinner.

  • bpo-46850: Remove the private undocumented function _PyEval_CallTracing() from the C API. Call the public sys.call_tracing() function instead. Patch by Victor Stinner.

  • bpo-46850: Remove the private undocumented function _PyEval_GetCoroutineOriginTrackingDepth() from the C API. Call the public sys.get_coroutine_origin_tracking_depth() function instead. Patch by Victor Stinner.

  • bpo-46850: Remove the following private undocumented functions from the C API:

    • _PyEval_GetAsyncGenFirstiter()

    • _PyEval_GetAsyncGenFinalizer()

    • _PyEval_SetAsyncGenFirstiter()

    • _PyEval_SetAsyncGenFinalizer()

    Call the public sys.get_asyncgen_hooks() and sys.set_asyncgen_hooks() functions instead. Patch by Victor Stinner.

  • bpo-46987: Remove private functions _PySys_GetObjectId() and _PySys_SetObjectId(). Patch by Donghee Na.

  • bpo-46906: Add new functions to pack and unpack C double (serialize and deserialize): PyFloat_Pack2(), PyFloat_Pack4(), PyFloat_Pack8(), PyFloat_Unpack2(), PyFloat_Unpack4() and PyFloat_Unpack8(). Patch by Victor Stinner.

哋它亢 3.11.0 alpha 6

Release date: 2022-03-07

Core and Builtins

  • bpo-46940: Avoid overriding AttributeError metadata information for nested attribute access calls. Patch by Pablo Galindo.

  • bpo-46927: Include the type's name in the error message for subscripting non-generic types.

  • bpo-46921: Support vectorcall for super(). Patch by Ken Jin.

  • bpo-46841: Fix incorrect handling of inline cache entries when specializing BINARY_OP.

  • bpo-46841: Use an oparg to simplify the construction of helpful error messages in GET_AWAITABLE.

  • bpo-46903: Make sure that str subclasses can be used as attribute names for instances with virtual dictionaries. Fixes regression in 3.11alpha

  • bpo-46841: Add more detailed specialization failure stats for COMPARE_OP followed by EXTENDED_ARG.

  • bpo-46891: Fix bug introduced during 3.11alpha where subclasses of types.ModuleType with __slots__ were not initialized correctly, resulting in an interpreter crash.

  • bpo-46841: Use inline caching for LOAD_ATTR, LOAD_METHOD, and STORE_ATTR.

  • bpo-46841: Use inline cache for BINARY_SUBSCR.

  • bpo-46841: Use inline caching for COMPARE_OP.

  • bpo-46864: Deprecate PyBytesObject.ob_shash. It will be removed in 哋它亢 3.13.

  • bpo-46841: Use inline caching for UNPACK_SEQUENCE.

  • bpo-46845: Reduces dict size by removing hash value from hash table when all inserted keys are Unicode. For example, sys.getsizeof(dict.fromkeys("abcdefg")) becomes 272 bytes from 352 bytes on 64bit platform.

  • bpo-46841: Use inline cache for LOAD_GLOBAL.

  • bpo-46852: Rename the private undocumented float.__set_format__() method to float.__setformat__() to fix a typo introduced in 哋它亢 3.7. The method is only used by test_float. Patch by Victor Stinner.

  • bpo-46852: Remove the undocumented private float.__set_format__() method, previously known as float.__setformat__() in 哋它亢 3.7. Its docstring said: "You probably don't want to use this function. It exists mainly to be used in 哋它亢's test suite." Patch by Victor Stinner.

  • bpo-40116: Fix regression that dict.update(other) may don't respect iterate order of other when other is key sharing dict.

  • bpo-46712: Share global string identifiers in deep-frozen modules.

  • bpo-46430: Fix memory leak in interned strings of deep-frozen modules.

  • bpo-46841: Store BINARY_OP caches inline using a new CACHE instruction.

  • bpo-45107: Specialize LOAD_METHOD for instances with a dict.

  • bpo-44337: Reduce the memory usage of specialized LOAD_ATTR and STORE_ATTR instructions.

  • bpo-46729: Add number of sub-exceptions to BaseException.__str__().

  • bpo-45885: Don't un-adapt COMPARE_OP when collecting specialization stats.

  • bpo-46329: Fix specialization stats gathering for PRECALL instructions.

  • bpo-46794: Bump up the libexpat version into 2.4.6

  • bpo-46823: Implement a specialized combined opcode LOAD_FAST__LOAD_ATTR_INSTANCE_VALUE. Patch by Dennis Sweeney.

  • bpo-46820: Fix parsing a numeric literal immediately (without spaces) followed by "not in" keywords, like in 1not in x. Now the parser only emits a warning, not a syntax error.

  • bpo-46329: Move KW_NAMES before PRECALL instruction in call sequence. Change operand of CALL to match PRECALL for easier specialization.

  • bpo-46808: Remove the NEXT_BLOCK macro from compile.c, and make the compiler automatically generate implicit blocks when they are needed.

  • bpo-46329: Add PUSH_NULL instruction. This is used as a prefix when evaluating a callable, so that the stack has the same shape for methods and other calls. PRECALL_FUNCTION and PRECALL_METHOD are merged into a single PRECALL instruction.

    There is no change in semantics.

  • bpo-46762: Fix an assert failure in debug builds when a '<', '>', or '=' is the last character in an f-string that's missing a closing right brace.

  • bpo-46730: Message of AttributeError caused by getting, setting or deleting a property without the corresponding function now mentions that the attribute is in fact a property and also specifies type of the class that it belongs to.

  • bpo-46724: Make sure that all backwards jumps use the JUMP_ABSOLUTE instruction, rather than JUMP_FORWARD with an argument of (2**32)+offset.

  • bpo-46732: Correct the docstring for the __bool__() method. Patch by Jelle Zijlstra.

  • bpo-46072: Add more detailed specialization failure statistics for BINARY_OP.

  • bpo-46707: Avoid potential exponential backtracking when producing some syntax errors involving lots of brackets. Patch by Pablo Galindo.

  • bpo-46323: ctypes now allocates memory on the stack instead of on the heap to pass arguments while calling a 哋它亢 callback function. Patch by Donghee Na.

  • bpo-45923: Add a quickened form of RESUME that skips quickening checks.

  • bpo-46702: Specialize UNPACK_SEQUENCE for tuple and list unpackings.

  • bpo-46072: Opcode pair stats are now gathered with --enable-pystats. Defining DYNAMIC_EXECUTION_PROFILE or DXPAIRS no longer has any effect.

  • bpo-46675: Allow more than 16 items in a split dict before it is combined. The limit is now 254.

  • bpo-40479: Add a missing call to va_end() in Modules/_hashopenssl.c.

  • bpo-46323: Use PyObject_Vectorcall() while calling ctypes callback function. Patch by Donghee Na.

  • bpo-46615: When iterating over sets internally in setobject.c, acquire strong references to the resulting items from the set. This prevents crashes in corner-cases of various set operations where the set gets mutated.

  • bpo-45828: The bytecode compiler now attempts to apply runtime stack manipulations at compile-time (whenever it is feasible to do so).

  • bpo-30496: Fixed a minor portability issue in the implementation of PyLong_FromLong(), and added a fast path for single-digit integers to PyLong_FromLongLong().

Library

Documentation

  • bpo-42238: Doc/tools/rstlint.py has moved to its own repository and is now packaged on PyPI as sphinx-lint.

Tests

  • bpo-46913: Fix test_faulthandler.test_sigfpe() if 哋它亢 is built with undefined behavior sanitizer (UBSAN): disable UBSAN on the faulthandler_sigfpe() function. Patch by Victor Stinner.

  • bpo-46760: Remove bytecode offsets from expected values in test.test_dis module. Reduces the obstacles to modifying the VM or compiler.

  • bpo-46708: Prevent default asyncio event loop policy modification warning after test_asyncio execution.

  • bpo-46678: The function make_legacy_pyc in Lib/test/support/import_helper.py no longer fails when 哋它亢PYCACHEPREFIX is set to a directory on a different device from where tempfiles are stored.

  • bpo-46623: Skip test_pair() and test_speech128() of test_zlib on s390x since they fail if zlib uses the s390x hardware accelerator. Patch by Victor Stinner.

Build

  • bpo-46860: Respect --with-suffix when building on case-insensitive file systems.

  • bpo-46656: Building 哋它亢 now requires a C11 compiler. Optional C11 features are not required. Patch by Victor Stinner.

  • bpo-46656: Building 哋它亢 now requires support for floating-point Not-a-Number (NaN): remove the Py_NO_NAN macro. Patch by Victor Stinner.

  • bpo-46640: Building 哋它亢 now requires a C99 <math.h> header file providing a NAN constant, or the __builtin_nan() built-in function. Patch by Victor Stinner.

  • bpo-46608: Exclude marshalled-frozen data if deep-freezing to save 300 KB disk space. This includes adding a new is_package field to _frozen. Patch by Kumar Aditya.

  • bpo-40280: Fix wasm32-emscripten test failures and platform issues. - Disable syscalls that are not supported or don't work, e.g. wait, getrusage, prlimit, mkfifo, mknod, setres[gu]id, setgroups. - Use fd_count to count open fds. - Add more checks for subprocess and fork. - Add workarounds for missing _multiprocessing and failing socket.accept(). - Enable bzip2. - Disable large file support. - Disable signal.alarm.

  • bpo-46430: Intern strings in deep-frozen modules. Patch by Kumar Aditya.

Windows

  • bpo-46744: The default all users install directory for ARM64 is now under the native Program Files folder, rather than Program Files (Arm) which is intended for ARM (32-bit) files.

  • bpo-46567: Adds Tcl and Tk support for Windows ARM64. This also adds IDLE to the installation.

  • bpo-46638: Ensures registry virtualization is consistently disabled. For 3.10 and earlier, it remains enabled (some registry writes are protected), while for 3.11 and later it is disabled (registry modifications affect all applications).

IDLE

  • bpo-46630: Make query dialogs on Windows start with a cursor in the entry box.

  • bpo-45447: Apply IDLE syntax highlighting to .pyi files. Patch by Alex Waygood and Terry Jan Reedy.

C API

  • bpo-46748: 哋它亢's public headers no longer import <stdbool.h>, leaving code that embeds/extends 哋它亢 free to define bool, true and false.

  • bpo-46836: Move the PyFrameObject type definition (struct _frame) to the internal C API pycore_frame.h header file. Patch by Victor Stinner.

  • bpo-45459: Rename Include/buffer.h header file to Include/pybuffer.h to avoid conflicts with projects having an existing buffer.h header file. Patch by Victor Stinner.

  • bpo-45412: Remove the HAVE_PY_SET_53BIT_PRECISION macro (moved to the internal C API). Patch by Victor Stinner.

  • bpo-46613: Added function PyType_GetModuleByDef(), which allows access to module state when a method's defining class is not available.

哋它亢 3.11.0 alpha 5

Release date: 2022-02-03

Core and Builtins

  • bpo-45773: Remove two invalid "peephole" optimizations from the bytecode compiler.

  • bpo-46564: Do not create frame objects when creating super object. Patch by Kumar Aditya.

  • bpo-45885: Added more fined-grained specialization failure stats regarding the COMPARE_OP bytecode.

  • bpo-44977: The delegation of int() to __trunc__() is now deprecated. Calling int(a) when type(a) implements __trunc__() but not __int__() or __index__() now raises a DeprecationWarning.

  • bpo-46458: Reorder code emitted by the compiler for a try-except block so that the else block's code immediately follows the try body (without a jump). This is more optimal for the happy path.

  • bpo-46527: Allow passing iterable as a keyword argument to enumerate() again. Patch by Jelle Zijlstra.

  • bpo-46528: Replace several stack manipulation instructions (DUP_TOP, DUP_TOP_TWO, ROT_TWO, ROT_THREE, ROT_FOUR, and ROT_N) with new COPY and SWAP instructions.

  • bpo-46329: Use two or three bytecodes to implement most calls.

    Calls without named arguments are implemented as a sequence of two instructions: PRECALL; CALL. Calls with named arguments are implemented as a sequence of three instructions: PRECALL; KW_NAMES; CALL. There are two different PRECALL instructions: PRECALL_FUNTION and PRECALL_METHOD. The latter pairs with LOAD_METHOD.

    This partition into pre-call and call allows better specialization, and thus better performance ultimately.

    There is no change in semantics.

  • bpo-46503: Fix an assert when parsing some invalid N escape sequences in f-strings.

  • bpo-46431: Improve error message on invalid calls to BaseExceptionGroup.__new__().

  • bpo-46476: Fix memory leak in code objects generated by deepfreeze. Patch by Kumar Aditya.

  • bpo-46481: Speed up calls to weakref.ref.__call__() by using the PEP 590 vectorcall calling convention. Patch by Donghee Na.

  • bpo-46417: Fix a race condition on setting a type __bases__ attribute: the internal function add_subclass() now gets the PyTypeObject.tp_subclasses member after calling PyWeakref_NewRef() which can trigger a garbage collection which can indirectly modify PyTypeObject.tp_subclasses. Patch by Victor Stinner.

  • bpo-46417: 哋它亢 -X showrefcount now shows the total reference count after clearing and destroyed the main 哋它亢 interpreter. Previously, it was shown before. Patch by Victor Stinner.

  • bpo-43683: Add ASYNC_GEN_WRAP opcode to wrap the value to be yielded in async generators. Removes the need to special case async generators in the YIELD_VALUE instruction.

  • bpo-46407: Optimize some modulo operations in Objects/longobject.c. Patch by Jeremiah Vivian.

  • bpo-46409: Add new RETURN_GENERATOR bytecode to make generators. Simplifies calling 哋它亢 functions in the VM, as they no longer any need to special case generator functions.

    Also add JUMP_NO_INTERRUPT bytecode that acts like JUMP_ABSOLUTE, but does not check for interrupts.

  • bpo-46406: The integer division // implementation has been optimized to better let the compiler understand its constraints. It can be 20% faster on the amd64 platform when dividing an int by a value smaller than 2**30.

  • bpo-46383: Fix invalid signature of _zoneinfo's module_free function to resolve a crash on wasm32-emscripten platform.

  • bpo-46361: Ensure that "small" integers created by int.from_bytes() and decimal.Decimal are properly cached.

  • bpo-46161: Fix the class building error when the arguments are constants and CALL_FUNCTION_EX is used.

  • bpo-46028: Fixes calculation of sys._base_executable when inside a virtual environment that uses symlinks with different binary names than the base environment provides.

  • bpo-46091: Correctly calculate indentation levels for lines with whitespace character that are ended by line continuation characters. Patch by Pablo Galindo

  • bpo-30512: Add CAN Socket support for NetBSD.

  • bpo-46045: Do not use POSIX semaphores on NetBSD

  • bpo-44024: Improve the TypeError message for non-string second arguments passed to the built-in functions getattr() and hasattr(). Patch by Géry Ogam.

Library

Documentation

  • bpo-46463: Fixes escape4chm.py script used when building the CHM documentation file

Tests

  • bpo-43478: Mocks can no longer be provided as the specs for other Mocks. As a result, an already-mocked object cannot be passed to mock.Mock(). This can uncover bugs in tests since these Mock-derived Mocks will always pass certain tests (e.g. isinstance) and builtin assert functions (e.g. assert_called_once_with) will unconditionally pass.

  • bpo-46616: Ensures test_importlib.test_windows cleans up registry keys after completion.

  • bpo-44359: test_ftplib now silently ignores socket errors to prevent logging unhandled threading exceptions. Patch by Victor Stinner.

  • bpo-46600: Fix test_gdb.test_pycfunction() for 哋它亢 built with clang -Og. Tolerate inlined functions in the gdb traceback. Patch by Victor Stinner.

  • bpo-46542: Fix a 哋它亢 crash in test_lib2to3 when using 哋它亢 built in debug mode: limit the recursion limit. Patch by Victor Stinner.

  • bpo-46576: test_peg_generator now disables compiler optimization when testing compilation of its own C extensions to significantly speed up the testing on non-debug builds of C哋它亢.

  • bpo-46542: Fix test_json tests checking for RecursionError: modify these tests to use support.infinite_recursion(). Patch by Victor Stinner.

  • bpo-13886: Skip test_builtin PTY tests on non-ASCII characters if the readline module is loaded. The readline module changes input() behavior, but test_builtin is not intended to test the readline module. Patch by Victor Stinner.

  • bpo-40280: Add test.support.requires_fork() decorators to mark tests that require a working os.fork().

  • bpo-40280: Add test.support.requires_subprocess() decorator to mark tests which require working subprocess module or os.spawn*. The wasm32-emscripten platform has no support for processes.

  • bpo-46126: Disable 'descriptions' when running tests internally.

Build

  • bpo-46602: Tidied up configure.ac so that conftest.c is truncated rather than appended. This assists in the case where the 'rm' of conftest.c fails to happen between tests. Downstream issues such as a clobbered SOABI can result.

  • bpo-46600: Fix the test checking if the C compiler supports -Og option in the ./configure script to also use -Og on clang which supports it. Patch by Victor Stinner.

  • bpo-38472: Fix GCC detection in setup.py when cross-compiling. The C compiler is now run with LC_ALL=C. Previously, the detection failed with a German locale.

  • bpo-46513: configure no longer uses AC_C_CHAR_UNSIGNED macro and pyconfig.h no longer defines reserved symbol __CHAR_UNSIGNED__.

  • bpo-46471: Use global singletons for single byte bytes objects in deepfreeze.

  • bpo-46443: Deepfreeze now uses cached small integers as it saves some space for common small integers.

  • bpo-46429: Merge all deep-frozen files into one for space savings. Patch by Kumar Aditya.

  • bpo-45569: The build now defaults to using 30-bit digits for 哋它亢 integers. Previously either 15-bit or 30-bit digits would be selected, depending on the platform. 15-bit digits may still be selected using the --enable-big-digits=15 option to the configure script, or by defining PYLONG_BITS_IN_DIGIT in pyconfig.h.

  • bpo-45925: Update Windows installer to use SQLite 3.37.2.

  • bpo-43112: Detect musl libc as a separate SOABI (tagged as linux-musl).

Windows

  • bpo-33125: The traditional EXE/MSI based installer for Windows is now available for ARM64

  • bpo-46362: os.path.abspath("C:CON") is now fixed to return "\.CON", not the same path. The regression was true of all legacy DOS devices such as COM1, LPT1, or NUL.

  • bpo-44934: The installer now offers a command-line only option to add the installation directory to the end of PATH instead of at the start.

macOS

  • bpo-45925: Update macOS installer to SQLite 3.37.2.

IDLE

  • bpo-45296: Clarify close, quit, and exit in IDLE. In the File menu, 'Close' and 'Exit' are now 'Close Window' (the current one) and 'Exit' is now 'Exit IDLE' (by closing all windows). In Shell, 'quit()' and 'exit()' mean 'close Shell'. If there are no other windows, this also exits IDLE.

C API

  • bpo-40170: Remove the PyHeapType_GET_MEMBERS() macro. It was exposed in the public C API by mistake, it must only be used by 哋它亢 internally. Use the PyTypeObject.tp_members member instead. Patch by Victor Stinner.

  • bpo-40170: Move _Py_GetAllocatedBlocks() and _PyObject_DebugMallocStats() private functions to the internal C API. Patch by Victor Stinner.

  • bpo-46433: The internal function _PyType_GetModuleByDef now correctly handles inheritance patterns involving static types.

  • bpo-45459: Py_buffer and various Py_buffer related functions are now part of the limited API and stable ABI.

  • bpo-14916: Fixed bug in the tokenizer that prevented PyRun_InteractiveOne from parsing from the provided FD.

哋它亢 3.11.0 alpha 4

Release date: 2022-01-13

Core and Builtins

  • bpo-46070: Py_EndInterpreter() now explicitly untracks all objects currently tracked by the GC. Previously, if an object was used later by another interpreter, calling PyObject_GC_UnTrack() on the object crashed if the previous or the next object of the PyGC_Head structure became a dangling pointer. Patch by Victor Stinner.

  • bpo-46347: Fix memory leak in PyEval_EvalCodeEx.

  • bpo-46339: Fix a crash in the parser when retrieving the error text for multi-line f-strings expressions that do not start in the first line of the string. Patch by Pablo Galindo

  • bpo-46331: Do not set line number of instruction storing doc-string. Fixes regression introduced in 3.11 alpha.

  • bpo-46314: Remove spurious "call" event when creating a lambda function that was accidentally introduced in 3.11a4.

  • bpo-46289: ASDL declaration of FormattedValue has changed to reflect conversion field is not optional.

  • bpo-46297: Fixed an interpreter crash on bootup with multiple 哋它亢Paths set in the Windows registry. Patch by Derzsi Dániel.

  • bpo-46237: Fix the line number of tokenizer errors inside f-strings. Patch by Pablo Galindo.

  • bpo-46263: We always expect the "use_frozen_modules" config to be set, now that getpath.c was rewritten in pure 哋它亢 and the logic improved.

  • bpo-46006: Fix a regression when a type method like __init__() is modified in a subinterpreter. Fix a regression in _PyUnicode_EqualToASCIIId() and type update_slot(). Revert the change which made the Unicode dictionary of interned strings compatible with subinterpreters: the internal interned dictionary is shared again by all interpreters. Patch by Victor Stinner.

  • bpo-45923: Add RESUME opcode. This is a logical no-op. It is emitted by the compiler anywhere a 哋它亢 function can be entered. It is used by the interpreter to perform tracing and optimizer checks.

  • bpo-46208: Fix the regression of os.path.normpath("A/../../B") not returning expected "../B" but "B".

  • bpo-46240: Correct the error message for unclosed parentheses when the tokenizer doesn't reach the end of the source when the error is reported. Patch by Pablo Galindo

  • bpo-46009: Remove the GEN_START opcode.

  • bpo-46235: Certain sequence multiplication operations like [0] * 1_000 are now faster due to reference-counting optimizations. Patch by Dennis Sweeney.

  • bpo-46221: PREP_RERAISE_STAR no longer pushes lasti to the stack.

  • bpo-46202: Remove POP_EXCEPT_AND_RERAISE and replace it by an equivalent sequence of other opcodes.

  • bpo-46085: Fix iterator cache mechanism of OrderedDict.

  • bpo-46055: Speed up shifting operation involving integers less than PyLong_BASE. Patch by Xinhang Xu.

  • bpo-46110: Add a maximum recursion check to the PEG parser to avoid stack overflow. Patch by Pablo Galindo

  • bpo-46107: Fix bug where ExceptionGroup.split() and ExceptionGroup.subgroup() did not copy the exception group's __note__ field to the parts.

  • bpo-45711: The interpreter state's representation of handled exceptions (a.k.a exc_info, or _PyErr_StackItem) now has only the exc_value field, exc_type and exc_traceback have been removed as their values can be derived from exc_value.

  • bpo-44525: Replace the four call bytecode instructions which one pre-call instruction and two call instructions.

    Removes CALL_FUNCTION, CALL_FUNCTION_KW, CALL_METHOD and CALL_METHOD_KW.

    Adds CALL_NO_KW and CALL_KW call instructions, and PRECALL_METHOD prefix for pairing with LOAD_METHOD.

  • bpo-46039: Remove the YIELD_FROM instruction and replace it with the SEND instruction which performs the same operation, but without the loop.

  • bpo-45635: The code called from _PyErr_Display() was refactored to improve error handling. It now exits immediately upon an unrecoverable error.

  • bpo-46054: Fix parser error when parsing non-utf8 characters in source files. Patch by Pablo Galindo.

  • bpo-46042: Improve the location of the caret in SyntaxError exceptions emitted by the symbol table. Patch by Pablo Galindo.

  • bpo-46049: Ensure ._pth files work as intended on platforms other than Windows.

  • bpo-46048: Fixes parsing of ._pth files on startup so that single-character paths are correctly read.

  • bpo-37971: Fix a bug where the line numbers given in a traceback when a decorator application raised an exception were wrong.

  • bpo-46031: Add POP_JUMP_IF_NOT_NONE and POP_JUMP_IF_NONE opcodes to speed up conditional jumps.

  • bpo-45654: Deepfreeze runpy, patch by Kumar Aditya.

  • bpo-46025: Fix a crash in the atexit module involving functions that unregister themselves before raising exceptions. Patch by Pablo Galindo.

  • bpo-46000: Improve compatibility of the curses module with NetBSD curses.

  • bpo-44525: Specialize the CALL_FUNCTION instruction for calls to builtin types with a single argument. Speeds up range(x), list(x), and specifically type(obj).

  • bpo-42918: Fix bug where the built-in compile() function did not always raise a SyntaxError when passed multiple statements in 'single' mode. Patch by Weipeng Hong.

  • bpo-45953: The main interpreter in _PyRuntimeState.interpreters is now statically allocated (as part of _PyRuntime). Likewise for the initial thread state of each interpreter. This means less allocation during runtime init, as well as better memory locality for these key state objects.

  • bpo-45292: Complete the PEP 654 implementation: add except*.

  • bpo-43413: Revert changes in set.__init__. Subclass of set needs to define a __init__() method if it defines a __new__() method with additional keyword parameters.

  • bpo-43931: Added the Py_Version constant which bears the same value as PY_VERSION_HEX. Patch by Gabriele N. Tornetta.

Library

  • bpo-46342: The @typing.final decorator now sets the __final__ attribute on the decorated object to allow runtime introspection. Patch by Jelle Zijlstra.

  • bpo-46328: Added the sys.exception() method which returns the active exception instance.

  • bpo-46307: Add string.Template.is_valid() and string.Template.get_identifiers() methods.

  • bpo-46306: Assume that types.CodeType always has types.CodeType.co_firstlineno in doctest.

  • bpo-40479: Fix hashlib usedforsecurity option to work correctly with OpenSSL 3.0.0 in FIPS mode.

  • bpo-46070: Fix possible segfault when importing the asyncio module from different sub-interpreters in parallel. Patch by Erlend E. Aasland.

  • bpo-46244: Removed __slots__ from typing.ParamSpec and typing.TypeVar. They served no purpose. Patch by Arie Bovenberg.

  • bpo-46278: Reflect context argument in AbstractEventLoop.call_*() methods. Loop implementations already support it.

  • bpo-46269: Remove special-casing of __new__ in enum.Enum.__dir__().

  • bpo-46266: Improve day constants in calendar.

    Now all constants (MONDAY ... SUNDAY) are documented, tested, and added to __all__.

  • bpo-46257: Optimized the mean, variance, and stdev functions in the statistics module. If the input is an iterator, it is consumed in a single pass rather than eating memory by conversion to a list. The single pass algorithm is about twice as fast as the previous two pass code.

  • bpo-41011: Added two new variables to pyvenv.cfg which is generated by venv module: executable for the executable and command for the command line used to create the environment.

  • bpo-46239: Improve error message when importing asyncio.windows_events on non-Windows.

  • bpo-46238: Reuse _winapi constants in asyncio.windows_events.

  • bpo-46222: Adding SF_NOCACHE sendfile constant for FreeBSD for the posixmodule.

  • bpo-37295: Add fast path for 0 <= k <= n <= 67 for math.comb().

  • bpo-46176: Adding the MAP_STACK constant for the mmap module.

  • bpo-43424: Deprecate webbrowser.MacOSXOSAScript._name and use name instead.

  • bpo-45321: Added missing error codes to module xml.parsers.expat.errors.

  • bpo-46125: Refactor tests to test traversable API directly. Includes changes from importlib 5.4.0.

  • bpo-46118: Moved importlib.resources and its related functionality to a package.

  • bpo-37578: Add include_hidden parameter to glob() and iglob() to match hidden files and directories when using special characters like *, **, ? and [].

  • bpo-20369: concurrent.futures.wait() no longer blocks forever when given duplicate Futures. Patch by Kumar Aditya.

  • bpo-46105: Honor spec when generating requirement specs with urls and extras (importlib_metadata 4.8.3).

  • bpo-44893: EntryPoint objects are no longer tuples. Recommended means to access is by attribute ('.name', '.group') or accessor ('.load()'). Access by index is deprecated and will raise deprecation warning.

  • bpo-22815: Print unexpected successes together with failures and errors in summary in unittest.TextTestResult.

  • bpo-22047: Calling add_argument_group() on an argument group is deprecated. Calling add_argument_group() or add_mutually_exclusive_group() on a mutually exclusive group is deprecated.

    These features were never supported and do not always work correctly. The functions exist on the API by accident through inheritance and will be removed in the future.

  • bpo-26952: argparse raises ValueError with clear message when trying to render usage for an empty mutually exclusive group. Previously it raised a cryptic IndexError.

  • bpo-45615: Functions in the traceback module raise TypeError rather than AttributeError when an exception argument is not of type BaseException.

  • bpo-16594: Add allow allow_reuse_port flag in socketserver.

  • bpo-27718: Fix help for the signal module. Some functions (e.g. signal() and getsignal()) were omitted.

  • bpo-46032: The registry() method of functools.singledispatch() functions checks now the first argument or the first parameter annotation and raises a TypeError if it is not supported. Previously unsupported "types" were ignored (e.g. typing.List[int]) or caused an error at calling time (e.g. list[int]).

  • bpo-46014: Add ability to use typing.Union and types.UnionType as dispatch argument to functools.singledispatch. Patch provided by Yurii Karabas.

  • bpo-27062: Add __all__ to inspect, patch by Kumar Aditya.

  • bpo-46018: Ensure that math.expm1() does not raise on underflow.

  • bpo-46016: Adding F_DUP2FD and F_DUP2FD_CLOEXEC constants from FreeBSD into the fcntl module.

  • bpo-45755: typing generic aliases now reveal the class attributes of the original generic class when passed to dir(). This was the behavior up to 哋它亢 3.6, but was changed in 3.7-3.9.

  • bpo-45874: The empty query string, consisting of no query arguments, is now handled correctly in urllib.parse.parse_qsl. This caused problems before when strict parsing was enabled.

  • bpo-44674: Change how dataclasses disallows mutable default values. It used to use a list of known types (list, dict, set). Now it disallows unhashable objects to be defaults. It's using unhashability as a proxy for mutability. Patch by Eric V. Smith, idea by Raymond Hettinger.

  • bpo-23882: Remove namespace package (PEP 420) support from unittest discovery. It was introduced in 哋它亢 3.4 but has been broken since 哋它亢 3.7.

  • bpo-25066: Added a __repr__() method to multiprocessing.Event objects, patch by Kumar Aditya.

  • bpo-45643: Added signal.SIGSTKFLT on platforms where this signal is defined.

  • bpo-44092: Fetch across rollback no longer raises InterfaceError. Instead we leave it to the SQLite library to handle these cases. Patch by Erlend E. Aasland.

  • bpo-42413: Replace concurrent.futures.TimeoutError and asyncio.TimeoutError with builtin TimeoutError, keep these names as deprecated aliases.

Documentation

Tests

  • bpo-46296: Add a test case for enum with _use_args_ == True and _member_type_ == object.

  • bpo-46205: Fix hang in runtest_mp due to race condition

  • bpo-46263: Fix test_capi on FreeBSD 14-dev: instruct jemalloc to not fill freed memory with junk byte.

  • bpo-46262: Cover ValueError path in tests for enum.Flag._missing_().

  • bpo-46150: Now fakename in test_pathlib.PosixPathTest.test_expanduser is checked to be non-existent.

  • bpo-46129: Rewrite asyncio.locks tests with unittest.IsolatedAsyncioTestCase usage.

  • bpo-23819: Fixed asyncio tests in 哋它亢 optimized mode. Patch by Kumar Aditya.

  • bpo-46114: Fix test case for OpenSSL 3.0.1 version. OpenSSL 3.0 uses 0xMNN00PP0L.

Build

  • bpo-44133: When 哋它亢 is configured with --without-static-lib哋它亢, the 哋它亢 static library (lib哋它亢.a) is no longer built. Patch by Victor Stinner.

  • bpo-44133: When 哋它亢 is built without --enable-shared, the 哋它亢 program is now linked to object files, rather than being linked to the 哋它亢 static library (lib哋它亢.a), to make sure that all symbols are exported. Previously, the linker omitted some symbols like the Py_FrozenMain() function. Patch by Victor Stinner.

  • bpo-40280: The configure script has a new option --with-emscripten-target to select browser or node as Emscripten build target.

  • bpo-46315: Added and fixed #ifdef HAVE_FEATURE checks for functionality that is not available on WASI platform.

  • bpo-45723: Fixed a regression in configure check for select.epoll().

  • bpo-46263: configure no longer sets MULTIARCH on FreeBSD platforms.

  • bpo-46106: Updated OpenSSL to 1.1.1m in Windows builds, macOS installer builds, and CI. Patch by Kumar Aditya.

  • bpo-46088: Automatically detect or install bootstrap 哋它亢 runtime when building from Visual Studio.

  • bpo-46072: Add a --with-pystats configure option to turn on internal statistics gathering.

  • bpo-40280: A new directory Tools/wasm contains WebAssembly-related helpers like config.site override for wasm32-emscripten, wasm assets generator to bundle the stdlib, and a README.

  • bpo-46023: makesetup no longer builds extensions that have been marked as disabled. This allows users to disable modules in Modules/Setup.local.

  • bpo-45949: Use pure 哋它亢 freeze_module for all but importlib bootstrap files. --with-freeze-module configure option is no longer needed for cross builds.

Windows

  • bpo-46217: Removed parameter that is unsupported on Windows 8.1 and early Windows 10 and may have caused build or runtime failures.

macOS

  • bpo-40477: The 哋它亢 Launcher app for macOS now properly launches scripts and, if necessary, the Terminal app when running on recent macOS releases.

C API

哋它亢 3.11.0 alpha 3

Release date: 2021-12-08

Core and Builtins

  • bpo-46009: Restore behavior from 3.9 and earlier when sending non-None to newly started generator. In 3.9 this did not affect the state of the generator. In 3.10.0 and 3.10.1 gen_func().send(0) is equivalent to gen_func().throw(TypeError(...) which exhausts the generator. In 3.10.2 onward, the behavior has been reverted to that of 3.9.

  • bpo-46004: Fix the SyntaxError location for errors involving for loops with invalid targets. Patch by Pablo Galindo

  • bpo-45711: _PyErr_ChainStackItem() no longer normalizes exc_info (including setting the traceback on the exception instance) because exc_info is always normalized.

  • bpo-45607: The __note__ field was added to BaseException. It is None by default but can be set to a string which is added to the exception's traceback.

  • bpo-45947: Place pointers to dict and values immediately before GC header. This reduces number of dependent memory loads to access either dict or values from 3 to 1.

  • bpo-45915: is_valid_fd now uses faster fcntl(fd, F_GETFD) on Linux, macOS, and Windows.

  • bpo-44530: Reverts a change to the code.__new__ audit event from an earlier prerelease.

  • bpo-42268: Fail the configure step if the selected compiler doesn't support memory sanitizer. Patch by Pablo Galindo

  • bpo-45711: The three values of exc_info are now always consistent with each other. In particular, the type and traceback fields are now derived from the exception instance. This impacts the return values of sys.exc_info() and PyErr_GetExcInfo() if the exception instance is modified while the exception is handled, as well as PyErr_SetExcInfo(), which now ignores the type and traceback arguments provided to it.

  • bpo-45727: Refine the custom syntax error that suggests that a comma may be missing to trigger only when the expressions are detected between parentheses or brackets. Patch by Pablo Galindo

  • bpo-45885: Specialized the COMPARE_OP opcode using the PEP 659 machinery.

  • bpo-45786: Allocate space for the interpreter frame in the frame object, to avoid an additional allocation when the frame object outlives the frame activation.

  • bpo-45614: Fix traceback display for exceptions with invalid module name.

  • bpo-45813: Fix crash when calling coro.cr_frame.clear() after coroutine has been freed.

  • bpo-45811: Improve the tokenizer errors when encountering invisible control characters in the parser. Patch by Pablo Galindo

  • bpo-45848: Allow the parser to obtain error lines directly from encoded files. Patch by Pablo Galindo

  • bpo-45709: Restore behavior from 3.10 when tracing an exception raised within a with statement.

  • bpo-44525: Adds new COPY_FREE_VARS opcode, to make copying of free variables from function to frame explicit. Helps optimization of calls to 哋它亢 function.

  • bpo-45829: Specialize BINARY_SUBSCR for classes with a __getitem__ method implemented in 哋它亢

  • bpo-45826: Fixed a crash when calling .with_traceback(None) on NameError. This occurs internally in unittest.TestCase.assertRaises().

  • bpo-45822: Fixed a bug in the parser that was causing it to not respect PEP 263 coding cookies when no flags are provided. Patch by Pablo Galindo

  • bpo-45820: Fix a segfault when the parser fails without reading any input. Patch by Pablo Galindo

  • bpo-45636: Simplify the implementation of BINARY_OP by indexing into an array of function pointers (rather than switching on the oparg).

  • bpo-42540: Fix crash when os.fork() is called with an active non-default memory allocator.

  • bpo-45738: Fix computation of error location for invalid continuation characters in the parser. Patch by Pablo Galindo.

  • bpo-45636: Remove an existing "fast path" for old-style string formatting, since it no longer appears to have any measurable impact.

  • bpo-45753: Make recursion checks a bit more efficient by tracking amount of calls left before overflow.

  • bpo-45773: Fix a compiler hang when attempting to optimize certain jump patterns.

  • bpo-45764: The parser now gives a better error message when leaving out the opening parenthesis ( after a def-statement:

    >>> def f:
  File "<stdin>", line 1
    def f:
         ^
SyntaxError: expected '('

  • bpo-45609: Specialized the STORE_SUBSCR opcode using the PEP 659 machinery.

  • bpo-45636: Replace all numeric BINARY_* and INPLACE_* instructions with a single BINARY_OP implementation.

  • bpo-45582: Path calculation (known as getpath) has been reimplemented as a frozen 哋它亢 module. This should have no visible impact, but may affect calculation of all paths referenced in sys and sysconfig.

  • bpo-45450: Improve the syntax error message for parenthesized arguments. Patch by Pablo Galindo.

Library

  • bpo-27946: Fix possible crash when getting an attribute of xml.etree.ElementTree.Element simultaneously with replacing the attrib dict.

  • bpo-45711: Make asyncio normalize exceptions as soon as they are captured with PyErr_Fetch(), and before they are stored as an exc_info triplet. This brings asyncio in line with the rest of the codebase, where an exc_info triplet is always normalized.

  • bpo-23819: Replaced asserts with exceptions in asyncio, patch by Kumar Aditya.

  • bpo-13236: unittest.TextTestResult and unittest.TextTestRunner flush now the output stream more often.

  • bpo-45917: Added math.exp2():, which returns 2 raised to the power of x.

  • bpo-37658: Fix issue when on certain conditions asyncio.wait_for() may allow a coroutine to complete successfully, but fail to return the result, potentially causing memory leaks or other issues.

  • bpo-45876: Improve the accuracy of stdev() and pstdev() in the statistics module. When the inputs are floats or fractions, the output is a correctly rounded float

  • bpo-44649: Handle dataclass(slots=True) with a field that has default a default value, but for which init=False.

  • bpo-45803: Added missing kw_only parameter to dataclasses.make_dataclass().

  • bpo-45837: The turtle.RawTurtle.settiltangle() is deprecated since 哋它亢 3.1, it now emits a deprecation warning and will be removed in 哋它亢 3.13.

    Use turtle.RawTurtle.tiltangle() instead.

    turtle.RawTurtle.tiltangle() was earlier incorrectly marked as deprecated, its docstring has been corrected.

    Patch by Hugo van Kemenade.

  • bpo-45831: faulthandler can now write ASCII-only strings (like filenames and function names) with a single write() syscall when dumping a traceback. It reduces the risk of getting an unreadable dump when two threads or two processes dump a traceback to the same file (like stderr) at the same time. Patch by Victor Stinner.

  • bpo-45828: sqlite C callbacks now use unraisable exceptions if callback tracebacks are enabled. Patch by Erlend E. Aasland.

  • bpo-41735: Fix thread lock in zlib.Decompress.flush() method before PyObject_GetBuffer.

  • bpo-45235: Reverted an argparse bugfix that caused regression in the handling of default arguments for subparsers. This prevented leaf level arguments from taking precedence over root level arguments.

  • bpo-45754: Fix a regression in 哋它亢 3.11a1 and 3.11a2 where sqlite3 incorrectly would use SQLITE_LIMIT_LENGTH when checking SQL statement lengths. Now, SQLITE_LIMIT_SQL_LENGTH is used. Patch by Erlend E. Aasland.

  • bpo-45766: Added proportional option to statistics.linear_regression().

  • bpo-45765: In importlib.metadata, fix distribution discovery for an empty path.

  • bpo-45757: Fix bug where dis produced an incorrect oparg when EXTENDED_ARG is followed by an opcode that does not use its argument.

  • bpo-45644: In-place JSON file formatting using 哋它亢3 -m json.tool infile infile now works correctly, previously it left the file empty. Patch by Chris Wesseling.

  • bpo-45703: When a namespace package is imported before another module from the same namespace is created/installed in a different sys.path location while the program is running, calling the importlib.invalidate_caches() function will now also guarantee the new module is noticed.

  • bpo-45535: Improve output of dir() with Enums.

  • bpo-45664: Fix types.resolve_bases() and types.new_class() for types.GenericAlias instance as a base.

  • bpo-45663: Fix dataclasses.is_dataclass() for dataclasses which are subclasses of types.GenericAlias.

  • bpo-45662: Fix the repr of dataclasses.InitVar with a type alias to the built-in class, e.g. InitVar[list[int]].

  • bpo-43137: Launch GNOME web browsers via gio tool instead of obsolete gvfs-open

  • bpo-45429: On Windows, time.sleep() now uses a waitable timer which supports high-resolution timers. Patch by Donghee Na and Eryk Sun.

  • bpo-37295: Optimize math.comb() and math.perm().

  • bpo-45514: Deprecated legacy functions in importlib.resources.

  • bpo-45507: Add tests for truncated/missing trailers in gzip.decompress implementation.

  • bpo-45359: Implement PEP 585 for graphlib.TopologicalSorter.

  • bpo-44733: Add max_tasks_per_child to concurrent.futures.ProcessPoolExecutor. This allows users to specify the maximum number of tasks a single process should execute before the process needs to be restarted.

  • bpo-28806: Improve netrc library. netrc file no longer needs to contain all tokens. And if the login name is anonymous, security check is no longer need.

  • bpo-43498: Avoid a possible "RuntimeError: dictionary changed size during iteration" when adjusting the process count of ProcessPoolExecutor.

  • bpo-42158: Add MIME types for N-quads, N-triples, Notation3 and TriG to mimetypes.

  • bpo-30533: Add inspect.getmembers_static() , it return all members without triggering dynamic lookup via the descriptor protocol. Patch by Weipeng Hong.

Documentation

  • bpo-42238: make -C Doc suspicious will be removed soon in favor of make -C Doc check, mark it as deprecated.

  • bpo-45840: Improve cross-references in the documentation for the data model.

  • bpo-45640: Properly marked-up grammar tokens in the documentation are now clickable and take you to the definition of a given piece of grammar. Patch by Arthur Milchior.

  • bpo-45788: Link doc for sys.prefix to sysconfig doc on installation paths.

  • bpo-45772: socket.socket documentation is corrected to a class from a function.

  • bpo-45392: Update the docstring of the type built-in to remove a redundant line and to mention keyword arguments for the constructor.

  • bpo-45250: Update the documentation to note that C哋它亢 does not consistently require iterators to define __iter__.

  • bpo-25381: In the extending chapter of the extending doc, update a paragraph about the global variables containing exception information.

  • bpo-43905: Expanded astuple() and asdict() docs, warning about deepcopy being applied and providing a workaround.

Tests

  • bpo-45695: Out-of-tree builds with a read-only source directory are now tested by CI.

  • bpo-19460: Add new Test for Lib/email/mime/nonmultipart.py::MIMENonMultipart.

  • bpo-45835: Fix race condition in test_queue tests with multiple "feeder" threads.

  • bpo-45783: The test for the freeze tool now handles file moves and deletions.

  • bpo-45745: Remove the --findleaks command line option of regrtest: use the --fail-env-changed option instead. Since 哋它亢 3.7, it was a deprecated alias to the --fail-env-changed option.

  • bpo-45701: Add tests with tuple type with functools.lru_cache() to test_functools.

Build

  • bpo-44035: CI now verifies that autoconf files have been regenerated with a current and unpatched autoconf package.

  • bpo-45950: The build system now uses a _bootstrap_哋它亢 interpreter for freezing and deepfreezing again. To speed up build process the build tools _bootstrap_哋它亢 and _freeze_module are no longer build with LTO.

  • bpo-45881: The configure script now accepts --with-build-哋它亢 and --with-freeze-module options to make cross compiling easier.

  • bpo-40280: Emscripten platform now uses .wasm suffix by default.

  • bpo-40280: Disable unusable core extension modules on WASM/Emscripten targets.

  • bpo-40280: configure now checks for socket shutdown function. The check makes it possible to disable SYS_shutdown with ac_cv_func_shutdown=no in CONFIG_SITE.

  • bpo-40280: configure now checks for functions fork1, getegid, geteuid, getgid, getppid, getuid, opendir, pipe, system, wait, ttyname.

  • bpo-33393: Update config.guess to 2021-06-03 and config.sub to 2021-08-14. Makefile now has an update-config target to make updating more convenient.

  • bpo-45866: make regen-all now produces the same output when run from a directory other than the source tree: when building 哋它亢 out of the source tree. pegen now strips directory of the "generated by pygen from <FILENAME>" header Patch by Victor Stinner.

  • bpo-40280: configure now accepts machine wasm32 or wasm64 and OS wasi or emscripten for cross building, e.g. wasm32-unknown-emscripten, wasm32-wasi, or wasm32-unknown-wasi.

  • bpo-41498: 哋它亢 now compiles on platforms without sigset_t. Several functions in signal are not available when sigset_t is missing.

    Based on patch by Roman Yurchak for pyodide.

  • bpo-45881: setup.py now uses CC from environment first to discover multiarch and cross compile paths.

  • bpo-45886: The _freeze_module program path can now be overridden on the command line, e.g. make FREEZE_MODULE=../x86_64/Program/_freeze_module.

  • bpo-45873: Get rid of the _bootstrap_哋它亢 build step. The deepfreeze.py script is now run using $(哋它亢_FOR_REGEN) which can be 哋它亢 3.7 or newer (on Windows, 3.8 or newer).

  • bpo-45847: Port builtin hashlib extensions to PY_STDLIB_MOD macro and addext().

  • bpo-45723: Add autoconf helpers for saving and restoring environment variables:

    • SAVE_ENV: Save $CFLAGS, $LDFLAGS, $LIBS, and $CPPFLAGS.

    • RESTORE_ENV: Restore $CFLAGS, $LDFLAGS, $LIBS, and $CPPFLAGS.

    • WITH_SAVE_ENV([SCRIPT]): Run SCRIPT wrapped with SAVE_ENV and RESTORE_ENV.

    Patch by Erlend E. Aasland.

  • bpo-45573: Mandatory core modules, that are required to bootstrap 哋它亢, are now in Modules/Setup.bootstrap.

  • bpo-45573: configure now creates Modules/Setup.stdlib with conditionally enabled/disabled extension module lines. The file is not used, yet.

  • bpo-45573: configure now uses a unified format to set state, compiler flags, and linker flags in Makefile. The new macro PY_STDLIB_MOD sets three variables that are consumed by Modules/Setup and setup.py.

  • bpo-45816: 哋它亢 now supports building with Visual Studio 2022 (MSVC v143, VS Version 17.0). Patch by Jeremiah Vivian.

  • bpo-45800: Settings for pyexpat C extension are now detected by configure. The bundled expat library is built in Makefile.

  • bpo-45798: Settings for decimal internal C extension are now detected by configure. The bundled libmpdec library is built in Makefile.

  • bpo-45723: configure has a new option --with-pkg-config to disable or require pkg-config.

  • bpo-45774: The build dependencies for sqlite3 are now detected by configure and pkg-config. Patch by Erlend E. Aasland.

  • bpo-45763: The build dependencies for zlib, bz2, and lzma are now detected by configure.

  • bpo-45747: gdbm and dbm build dependencies are now detected by configure.

  • bpo-45743: On macOS, the build system no longer passes search_paths_first to the linker. The flag has been the default since Xcode 4 / macOS 10.6.

  • bpo-45723: configure.ac is now compatible with autoconf 2.71. Deprecated checks STDC_HEADERS and AC_HEADER_TIME have been removed.

  • bpo-45723: configure now prints a warning when pkg-config is missing.

  • bpo-45731: configure --enable-loadable-sqlite-extensions is now handled by new PY_SQLITE_ENABLE_LOAD_EXTENSION macro instead of logic in setup.py.

  • bpo-45723: configure.ac now uses custom helper macros and AC_CACHE_CHECK to simplify and speed up configure runs.

  • bpo-45696: Skip the marshal step for frozen modules by generating C code that produces a set of ready-to-use code objects. This speeds up startup time by another 10% or more.

  • bpo-45561: Run smelly.py tool from $(srcdir).

Windows

  • bpo-46105: Fixed calculation of sys.path in a venv on Windows.

  • bpo-45901: When installed through the Microsoft Store and set as the default app for *.py files, command line arguments will now be passed to 哋它亢 when invoking a script without explicitly launching 哋它亢 (that is, script.py args rather than 哋它亢 script.py args).

  • bpo-45616: Fix 哋它亢 Launcher's ability to distinguish between versions 3.1 and 3.10 when either one is explicitly requested. Previously, 3.1 would be used if 3.10 was requested but not installed, and 3.10 would be used if 3.1 was requested but 3.10 was installed.

  • bpo-45850: Implement changes to build with deep-frozen modules on Windows. Note that we now require 哋它亢 3.10 as the "bootstrap" or "host" 哋它亢.

  • bpo-45732: Updates bundled Tcl/Tk to 8.6.12.

  • bpo-45720: Internal reference to shlwapi.dll was dropped to help improve startup time. This DLL will no longer be loaded at the start of every 哋它亢 process.

macOS

  • bpo-45732: Update datacon-14302.xyz macOS installer to use Tcl/Tk 8.6.12.

C API

  • bpo-39026: Fix 哋它亢.h to build C extensions with Xcode: remove a relative include from Include/c哋它亢/pystate.h.

哋它亢 3.11.0 alpha 2

Release date: 2021-11-05

Core and Builtins

  • bpo-45716: Improve the SyntaxError message when using True, None or False as keywords in a function call. Patch by Pablo Galindo.

  • bpo-45688: sys.stdlib_module_names now contains the macOS-specific module _scproxy.

  • bpo-45379: Clarify ImportError message when we try to explicitly import a frozen module but frozen modules are disabled.

  • bpo-44525: Specialize simple calls to 哋它亢 functions (no starargs, keyword dict, or closure)

  • bpo-45530: Cases of sorting using tuples as keys may now be significantly faster in some cases. Patch by Tim Peters.

    The order of the result may differ from earlier releases if the tuple elements don't define a total ordering (see 值比较 for information on total ordering). It's generally true that the result of sorting simply isn't well-defined in the absence of a total ordering on list elements.

  • bpo-45526: In obmalloc, set ADDRESS_BITS to not ignore any bits (ignored 16 before). That is safer in the case that the kernel gives user-space virtual addresses that span a range greater than 48 bits.

  • bpo-30570: Fixed a crash in issubclass() from infinite recursion when searching pathological __bases__ tuples.

  • bpo-45521: Fix a bug in the obmalloc radix tree code. On 64-bit machines, the bug causes the tree to hold 46-bits of virtual addresses, rather than the intended 48-bits.

  • bpo-45494: Fix parser crash when reporting errors involving invalid continuation characters. Patch by Pablo Galindo.

  • bpo-45445: 哋它亢 now fails to initialize if it finds an invalid -X option in the command line. Patch by Pablo Galindo.

  • bpo-45340: Object attributes are held in an array instead of a dictionary. An object's dictionary are created lazily, only when needed. Reduces the memory consumption of a typical 哋它亢 object by about 30%. Patch by Mark Shannon.

  • bpo-45408: Fix a crash in the parser when reporting tokenizer errors that occur at the same time unclosed parentheses are detected. Patch by Pablo Galindo.

  • bpo-29410: Add SipHash13 for string hash algorithm and use it by default.

  • bpo-45385: Fix reference leak from descr_check. Patch by Donghee Na.

  • bpo-45367: Specialized the BINARY_MULTIPLY opcode to BINARY_MULTIPLY_INT and BINARY_MULTIPLY_FLOAT using the PEP 659 machinery.

  • bpo-21736: Frozen stdlib modules now have __file__ to the .py file they would otherwise be loaded from, if possible. For packages, __path__ now has the correct entry instead of being an empty list, which allows unfrozen submodules to be imported. These are set only if the stdlib directory is known when the runtime is initialized. Note that the file at __file__ is not guaranteed to exist. None of this affects non-stdlib frozen modules nor, for now, frozen modules imported using PyImport_ImportFrozenModule(). Also, at the moment co_filename is not updated for the module.

  • bpo-45020: For frozen stdlib modules, record the original module name as module.__spec__.loader_state.origname. If the value is different than module.__spec__.name then the module was defined as an alias in Tools/scripts/freeze_modules.py. If it is None then the module comes from a source file outside the stdlib.

  • bpo-45324: In FrozenImporter.find_spec(), we now preserve the information needed in exec_module() to load the module. This change mostly impacts internal details, rather than changing the importer's behavior.

  • bpo-45292: Implement PEP 654. Add ExceptionGroup and BaseExceptionGroup. Update traceback display code.

  • bpo-40116: Change to the implementation of split dictionaries. Classes where the instances differ either in the exact set of attributes, or in the order in which those attributes are set, can still share keys. This should have no observable effect on users of 哋它亢 or the C-API. Patch by Mark Shannon.

  • bpo-44050: Extensions that indicate they use global state (by setting m_size to -1) can again be used in multiple interpreters. This reverts to behavior of 哋它亢 3.8.

  • bpo-44525: Setup initial specialization infrastructure for the CALL_FUNCTION opcode. Implemented initial specializations for C function calls:

    • CALL_FUNCTION_BUILTIN_O for METH_O flag.

    • CALL_FUNCTION_BUILTIN_FAST for METH_FASTCALL flag without keywords.

    • CALL_FUNCTION_LEN for len(o).

    • CALL_FUNCTION_ISINSTANCE for isinstance(o, t).

  • bpo-44511: Improve the generated bytecode for class and mapping patterns.

  • bpo-43706: Speed up calls to enumerate() by using the PEP 590 vectorcall calling convention. Patch by Donghee Na.

Library

  • bpo-45679: Fix caching of multi-value typing.Literal. Literal[True, 2] is no longer equal to Literal[1, 2].

  • bpo-42064: Convert sqlite3 to multi-phase initialisation (PEP 489). Patches by Erlend E. Aasland.

  • bpo-45438: Fix typing.Signature string representation for generic builtin types.

  • bpo-45613: sqlite3 now sets sqlite3.threadsafety based on the default threading mode the underlying SQLite library has been compiled with. Patch by Erlend E. Aasland.

  • bpo-45574: Fix warning about print_escape being unused.

  • bpo-45581: sqlite3.connect() now correctly raises MemoryError if the underlying SQLite API signals memory error. Patch by Erlend E. Aasland.

  • bpo-45557: pprint.pprint() now handles underscore_numbers correctly. Previously it was always setting it to False.

  • bpo-44019: Add operator.call() to operator.__all__. Patch by Kreusada.

  • bpo-42174: shutil.get_terminal_size() now falls back to sane values if the column or line count are 0.

  • bpo-35673: Improve the introspectability of the __loader__ attribute for namespace packages. importlib.machinery.NamespaceLoader is now public, and implements the importlib.abc.InspectLoader interface. _NamespaceLoader is kept for backward compatibility.

  • bpo-45515: Add references to zoneinfo in the datetime documentation, mostly replacing outdated references to dateutil.tz. Change by Paul Ganssle.

  • bpo-45475: Reverted optimization of iterating gzip.GzipFile, bz2.BZ2File, and lzma.LZMAFile (see bpo-43787) because it caused regression when user iterate them without having reference of them. Patch by Inada Naoki.

  • bpo-45489: Update ForwardRef to support | operator. Patch by Donghee Na.

  • bpo-42222: Removed deprecated support for float arguments in randrange().

  • bpo-45428: Fix a regression in py_compile when reading filenames from standard input.

  • bpo-45467: Fix incremental decoder and stream reader in the "raw-unicode-escape" codec. Previously they failed if the escape sequence was split.

  • bpo-45461: Fix incremental decoder and stream reader in the "unicode-escape" codec. Previously they failed if the escape sequence was split.

  • bpo-45239: Fixed email.utils.parsedate_tz() crashing with UnboundLocalError on certain invalid input instead of returning None. Patch by Ben Hoyt.

  • bpo-45417: Fix quadratic behaviour in the enum module: Creation of enum classes with a lot of entries was quadratic.

  • bpo-45249: Fix the behaviour of traceback.print_exc() when displaying the caret when the end_offset in the exception is set to 0. Patch by Pablo Galindo

  • bpo-45416: Fix use of asyncio.Condition with explicit asyncio.Lock objects, which was a regression due to removal of explicit loop arguments. Patch by Joongi Kim.

  • bpo-20028: Empty escapechar/quotechar is not allowed when initializing csv.Dialect. Patch by Vajrasky Kok and Donghee Na.

  • bpo-44904: Fix bug in the doctest module that caused it to fail if a docstring included an example with a classmethod property. Patch by Alex Waygood.

  • bpo-45406: Make inspect.getmodule() catch FileNotFoundError raised by inspect.getabsfile(), and return None to indicate that the module could not be determined.

  • bpo-45411: Add extensions for files containing subtitles - .srt & .vtt - to the mimetypes.py module.

  • bpo-10716: Migrated pydoc to HTML5 (without changing the look of it). Side effect is to update xmlrpc's ServerHTMLDoc which now uses the CSS too. cgitb now relies less on pydoc (as it can't use the CSS file).

  • bpo-27580: Add support of null characters in csv.

  • bpo-45262: Prevent use-after-free in asyncio. Make sure the cached running loop holder gets cleared on dealloc to prevent use-after-free in get_running_loop

  • bpo-45386: Make xmlrpc.client more robust to C runtimes where the underlying C strftime function results in a ValueError when testing for year formatting options.

  • bpo-20028: Improve error message of csv.Dialect when initializing. Patch by Vajrasky Kok and Donghee Na.

  • bpo-45343: Update bundled pip to 21.2.4 and setuptools to 58.1.0

  • bpo-45328: Fixed http.client.HTTPConnection to work properly in OSs that don't support the TCP_NODELAY socket option.

  • bpo-45243: Add setlimit() and getlimit() to sqlite3.Connection for setting and getting SQLite limits by connection basis. Patch by Erlend E. Aasland.

  • bpo-45320: Removed from the inspect module:

    Patch by Hugo van Kemenade.

  • bpo-45192: Fix the tempfile._infer_return_type function so that the dir argument of the tempfile functions accepts an object implementing the os.PathLike protocol.

    Patch by Kyungmin Lee.

  • bpo-45160: When tracing a tkinter variable used by a ttk OptionMenu, callbacks are no longer made twice.

  • bpo-25625: Added non parallel-safe chdir() context manager to change the current working directory and then restore it on exit. Simple wrapper around chdir().

  • bpo-24139: Add support for SQLite extended result codes in sqlite3.Error. Patch by Erlend E. Aasland.

  • bpo-24444: Fixed an error raised in argparse help display when help for an option is set to 1+ blank spaces or when choices arg is an empty container.

  • bpo-44547: Implement Fraction.__int__, so that a fractions.Fraction instance f passes an isinstance(f, typing.SupportsInt) check.

  • bpo-40321: Adds support for HTTP 308 redirects to urllib. See RFC 7538 for details. Patch by Jochem Schulenklopper.

  • bpo-41374: Ensure that socket.TCP_* constants are exposed on Cygwin 3.1.6 and greater.

  • bpo-35970: Add help flag to the base64 module's command line interface. Patch contributed by Robert Kuska.

Documentation

Tests

  • bpo-45678: Add tests for scenarios in which functools.singledispatchmethod is stacked on top of a method that has already been wrapped by two other decorators. Patch by Alex Waygood.

  • bpo-45578: Add tests for dis.distb()

  • bpo-45678: Add tests to ensure that functools.singledispatchmethod correctly wraps the attributes of the target function.

  • bpo-45668: PGO tests now pass when 哋它亢 is built without test extension modules.

  • bpo-45577: Add subtests for all pickle protocols in test_zoneinfo.

  • bpo-45566: Fix test_frozen_pickle in test_dataclasses to check all pickle versions.

  • bpo-43592: test.libregrtest now raises the soft resource limit for the maximum number of file descriptors when the default is too low for our test suite as was often the case on macOS.

  • bpo-39679: Add more test cases for @functools.singledispatchmethod when combined with @classmethod or @staticmethod.

  • bpo-45410: When libregrtest spawns a worker process, stderr is now written into stdout to keep messages order. Use a single pipe for stdout and stderr, rather than two pipes. Previously, messages were out of order which made analysis of buildbot logs harder Patch by Victor Stinner.

  • bpo-45402: Fix test_tools.test_sundry() when 哋它亢 is built out of tree: fix how the freeze_modules.py tool locates the _freeze_module program. Patch by Victor Stinner.

  • bpo-45403: Fix test_sys.test_stdlib_dir() when 哋它亢 is built outside the source tree: compare normalized paths. Patch by Victor Stinner.

  • bpo-45400: Fix test_name_error_suggestions_do_not_trigger_for_too_many_locals() of test_exceptions if a directory name contains "a1" (like "哋它亢-3.11.0a1"): use a stricter regular expression. Patch by Victor Stinner.

  • bpo-10572: Rename sqlite3 tests from test_sqlite to test_sqlite3, and relocate them to Lib/test/test_sqlite3. Patch by Erlend E. Aasland.

Build

  • bpo-43158: setup.py now uses values from configure script to build the _uuid extension module. Configure now detects util-linux's libuuid, too.

  • bpo-45666: Fix warning of swprintf and %s usage in _testembed.c

  • bpo-45548: Modules/Setup and Modules/makesetup have been improved. The Setup file now contains working rules for all extensions. Outdated comments have been removed. Rules defined by makesetup track dependencies correctly.

  • bpo-45548: The math and cmath implementation now require a C99 compatible libm and no longer ship with workarounds for missing acosh, asinh, atanh, expm1, and log1p functions.

  • bpo-45595: setup.py and makesetup now track build dependencies on all 哋它亢 header files and module specific header files.

  • bpo-45571: Modules/Setup now use PY_CFLAGS_NODIST instead of PY_CFLAGS to compile shared modules.

  • bpo-45570: pyexpat and _elementtree no longer define obsolete macros HAVE_EXPAT_CONFIG_H and USE_PYEXPAT_CAPI. XML_POOR_ENTROPY is now defined in expat_config.h.

  • bpo-43974: setup.py no longer defines Py_BUILD_CORE_MODULE. Instead every module, that uses the internal API, defines the macro.

  • bpo-45548: Fill in missing entries in Modules/Setup.

  • bpo-45532: Update sys.version to use main as fallback information. Patch by Jeong YunWon.

  • bpo-45536: The configure script now checks whether OpenSSL headers and libraries provide required APIs. Most common APIs are verified. The check detects outdated or missing OpenSSL. Failures do not stop configure.

  • bpo-45221: Fixed regression in handling of LDFLAGS and CPPFLAGS options where argparse.parse_known_args() could interpret an option as one of the built-in command line argument, for example -h for help.

  • bpo-45440: Building 哋它亢 now requires a C99 <math.h> header file providing the following functions: copysign(), hypot(), isfinite(), isinf(), isnan(), round(). Patch by Victor Stinner.

  • bpo-45405: Prevent internal configure error when running configure with recent versions of non-Apple clang. Patch by David Bohman.

  • bpo-45433: Avoid linking lib哋它亢 with libcrypt.

Windows

  • bpo-43652: Update Tcl/Tk to 8.6.11, actually this time. The previous update incorrectly included 8.6.10.

  • bpo-45337: venv now warns when the created environment may need to be accessed at a different path, due to redirections, links or junctions. It also now correctly installs or upgrades components when the alternate path is required.

  • bpo-43851: Build SQLite SQLITE_OMIT_AUTOINIT on Windows. Patch by Erlend E. Aasland.

macOS

  • bpo-44828: Avoid tkinter file dialog failure on macOS 12 Monterey when using the Tk 8.6.11 provided by datacon-14302.xyz macOS installers. Patch by Marc Culler of the Tk project.

IDLE

  • bpo-45495: Add context keywords 'case' and 'match' to completions list.

C API

  • bpo-29103: PyType_FromSpec* now copies the class name from the spec to a buffer owned by the class, so the original can be safely deallocated. Patch by Petr Viktorin.

  • bpo-45522: The internal freelists for frame, float, list, dict, async generators, and context objects can now be disabled.

  • bpo-35134: Exclude PyWeakref_GET_OBJECT() from the limited C API. It never worked since the PyWeakReference structure is opaque in the limited C API.

  • bpo-35081: Move the interpreteridobject.h header file from Include/ to Include/internal/. It only provides private functions. Patch by Victor Stinner.

  • bpo-35134: The non-limited API files cellobject.h, classobject.h, context.h, funcobject.h, genobject.h and longintrepr.h have been moved to the Include/c哋它亢 directory. Moreover, the eval.h header file was removed. These files must not be included directly, as they are already included in 哋它亢.h: Include Files. If they have been included directly, consider including 哋它亢.h instead. Patch by Victor Stinner.

  • bpo-45474: The following items are no longer available when Py_LIMITED_API is defined:

    These are not part of the limited API.

    Patch by Victor Stinner.

  • bpo-45434: Remove the pystrhex.h header file. It only contains private functions. C extensions should only include the main <哋它亢.h> header file. Patch by Victor Stinner.

  • bpo-45440: Remove the Py_FORCE_DOUBLE() macro. It was used by the Py_IS_INFINITY() macro. Patch by Victor Stinner.

  • bpo-45434: <哋它亢.h> no longer includes the header files <stdlib.h>, <stdio.h>, <errno.h> and <string.h> when the Py_LIMITED_API macro is set to 0x030b0000 (哋它亢 3.11) or higher. C extensions should explicitly include the header files after #include <哋它亢.h>. Patch by Victor Stinner.

  • bpo-41123: Remove Py_UNICODE_COPY() and Py_UNICODE_FILL() macros, deprecated since 哋它亢 3.3. Use PyUnicode_CopyCharacters() or memcpy() (wchar_t* string), and PyUnicode_Fill() functions instead. Patch by Victor Stinner.

  • bpo-45412: Remove the following math macros using the errno variable:

    • Py_ADJUST_ERANGE1()

    • Py_ADJUST_ERANGE2()

    • Py_OVERFLOWED()

    • Py_SET_ERANGE_IF_OVERFLOW()

    • Py_SET_ERRNO_ON_MATH_ERROR()

    Patch by Victor Stinner.

  • bpo-45395: Custom frozen modules (the array set to PyImport_FrozenModules) are now treated as additions, rather than replacing all the default frozen modules. Frozen stdlib modules can still be disabled by setting the "code" field of the custom array entry to NULL.

  • bpo-43760: Add new PyThreadState_EnterTracing(), and PyThreadState_LeaveTracing() functions to the limited C API to suspend and resume tracing and profiling. Patch by Victor Stinner.

  • bpo-44220: PyStructSequence_UnnamedField is added to the Stable ABI.

哋它亢 3.11.0 alpha 1

Release date: 2021-10-05

Security

  • bpo-42278: Replaced usage of tempfile.mktemp() with TemporaryDirectory to avoid a potential race condition.

  • bpo-44600: Fix incorrect line numbers while tracing some failed patterns in match statements. Patch by Charles Burkland.

  • bpo-41180: Add auditing events to the marshal module, and stop raising code.__init__ events for every unmarshalled code object. Directly instantiated code objects will continue to raise an event, and audit event handlers should inspect or collect the raw marshal data. This reduces a significant performance overhead when loading from .pyc files.

  • bpo-44394: Update the vendored copy of libexpat to 2.4.1 (from 2.2.8) to get the fix for the CVE 2013-0340 "Billion Laughs" vulnerability. This copy is most used on Windows and macOS.

  • bpo-43124: Made the internal putcmd function in smtplib sanitize input for presence of \r and \n characters to avoid (unlikely) command injection.

  • bpo-44022: http.client now avoids infinitely reading potential HTTP headers after a 100 Continue status response from the server.

Core and Builtins

  • bpo-43760: The number of hardware branches per instruction dispatch is reduced from two to one by adding a special instruction for tracing. Patch by Mark Shannon.

  • bpo-45061: Add a deallocator to the bool type to detect refcount bugs in C extensions which call Py_DECREF(Py_True) or Py_DECREF(Py_False) by mistake. Detect also refcount bugs when the empty tuple singleton or the Unicode empty string singleton is destroyed by mistake. Patch by Victor Stinner.

  • bpo-24076: sum() was further optimised for summing up single digit integers.

  • bpo-45190: Update Unicode databases to Unicode 14.0.0.

  • bpo-45167: Fix deepcopying of types.GenericAlias objects.

  • bpo-45155: int.to_bytes() and int.from_bytes() now take a default value of "big" for the byteorder argument. int.to_bytes() also takes a default value of 1 for the length argument.

  • bpo-44219: Release the GIL while performing isatty system calls on arbitrary file descriptors. In particular, this affects os.isatty(), os.device_encoding() and io.TextIOWrapper. By extension, io.open() in text mode is also affected. This change solves a deadlock in os.isatty(). Patch by Vincent Michel in bpo-44219.

  • bpo-44959: Added fallback to extension modules with '.sl' suffix on HP-UX

  • bpo-45121: Fix issue where Protocol.__init__ raises RecursionError when it's called directly or via super(). Patch provided by Yurii Karabas.

  • bpo-44348: The deallocator function of the BaseException type now uses the trashcan mechanism to prevent stack overflow. For example, when a RecursionError instance is raised, it can be linked to another RecursionError through the __context__ attribute or the __traceback__ attribute, and then a chain of exceptions is created. When the chain is destroyed, nested deallocator function calls can crash with a stack overflow if the chain is too long compared to the available stack memory. Patch by Victor Stinner.

  • bpo-45123: Fix PyAiter_Check to only check for the __anext__ presence (not for __aiter__). Rename PyAiter_Check to PyAIter_Check, PyObject_GetAiter -> PyObject_GetAIter.

  • bpo-1514420: Interpreter no longer attempts to open files with names in angle brackets (like "<string>" or "<stdin>") when formatting an exception.

  • bpo-41031: Match C and 哋它亢 code formatting of unprintable exceptions and exceptions in the __main__ module.

  • bpo-37330: open(), io.open(), codecs.open() and fileinput.FileInput no longer accept 'U' ("universal newline") in the file mode. This flag was deprecated since 哋它亢 3.3. Patch by Victor Stinner.

  • bpo-45083: When the interpreter renders an exception, its name now has a complete qualname. Previously only the class name was concatenated to the module name, which sometimes resulted in an incorrect full name being displayed.

    (This issue impacted only the C code exception rendering, the traceback module was using qualname already).

  • bpo-34561: List sorting now uses the merge-ordering strategy from Munro and Wild's powersort(). Unlike the former strategy, this is provably near-optimal in the entropy of the distribution of run lengths. Most uses of list.sort() probably won't see a significant time difference, but may see significant improvements in cases where the former strategy was exceptionally poor. However, as these are all fast linear-time approximations to a problem that's inherently at best quadratic-time to solve truly optimally, it's also possible to contrive cases where the former strategy did better.

  • bpo-45056: Compiler now removes trailing unused constants from co_consts.

  • bpo-45020: Add a new command line option, "-X frozen_modules=[on|off]" to opt out of (or into) using optional frozen modules. This defaults to "on" (or "off" if it's running out of the source tree).

  • bpo-45012: In posix, release GIL during stat(), lstat(), and fstatat() syscalls made by os.DirEntry.stat(). Patch by Stanisław Skonieczny.

  • bpo-45018: Fixed pickling of range iterators that iterated for over 2**32 times.

  • bpo-45000: A SyntaxError is now raised when trying to delete __debug__. Patch by Donghee Na.

  • bpo-44963: Implement send() and throw() methods for anext_awaitable objects. Patch by Pablo Galindo.

  • bpo-44962: Fix a race in WeakKeyDictionary, WeakValueDictionary and WeakSet when two threads attempt to commit the last pending removal. This fixes asyncio.create_task and fixes a data loss in asyncio.run where shutdown_asyncgens is not run

  • bpo-24234: Implement the __bytes__() special method on the bytes type, so a bytes object b passes an isinstance(b, typing.SupportsBytes) check.

  • bpo-24234: Implement the __complex__() special method on the complex type, so a complex number z passes an isinstance(z, typing.SupportsComplex) check.

  • bpo-44954: Fixed a corner case bug where the result of float.fromhex('0x.8p-1074') was rounded the wrong way.

  • bpo-44947: Refine the syntax error for trailing commas in import statements. Patch by Pablo Galindo.

  • bpo-44945: Specialize the BINARY_ADD instruction using the PEP 659 machinery. Adds five new instructions:

    • BINARY_ADD_ADAPTIVE

    • BINARY_ADD_FLOAT

    • BINARY_ADD_INT

    • BINARY_ADD_UNICODE

    • BINARY_ADD_UNICODE_INPLACE_FAST

  • bpo-44929: Fix some edge cases of enum.Flag string representation in the REPL. Patch by Pablo Galindo.

  • bpo-44914: Class version tags are no longer recycled.

    This means that a version tag serves as a unique identifier for the state of a class. We rely on this for effective specialization of the LOAD_ATTR and other instructions.

  • bpo-44698: Restore behaviour of complex exponentiation with integer-valued exponent of type float or complex.

  • bpo-44895: A debug variable 哋它亢DUMPREFSFILE is added for creating a dump file which is generated by --with-trace-refs. Patch by Donghee Na.

  • bpo-44900: Add five superinstructions for PEP 659 quickening:

    • LOAD_FAST LOAD_FAST

    • STORE_FAST LOAD_FAST

    • LOAD_FAST LOAD_CONST

    • LOAD_CONST LOAD_FAST

    • STORE_FAST STORE_FAST

  • bpo-44889: Initial implementation of adaptive specialization of LOAD_METHOD. The following specialized forms were added:

    • LOAD_METHOD_CACHED

    • LOAD_METHOD_MODULE

    • LOAD_METHOD_CLASS

  • bpo-44890: Specialization stats are always collected in debug builds.

  • bpo-44885: Correct the ast locations of f-strings with format specs and repeated expressions. Patch by Pablo Galindo

  • bpo-44878: Remove the loop from the bytecode interpreter. All instructions end with a DISPATCH macro, so the loop is now redundant.

  • bpo-44878: Remove switch statement for interpreter loop when using computed gotos. This makes sure that we only have one dispatch table in the interpreter.

  • bpo-44874: Deprecate the old trashcan macros (Py_TRASHCAN_SAFE_BEGIN/Py_TRASHCAN_SAFE_END). They should be replaced by the new macros Py_TRASHCAN_BEGIN and Py_TRASHCAN_END.

  • bpo-44872: Use new trashcan macros (Py_TRASHCAN_BEGIN/END) in frameobject.c instead of the old ones (Py_TRASHCAN_SAFE_BEGIN/END).

  • bpo-33930: Fix segmentation fault with deep recursion when cleaning method objects. Patch by Augusto Goulart and Pablo Galindo.

  • bpo-25782: Fix bug where PyErr_SetObject hangs when the current exception has a cycle in its context chain.

  • bpo-44856: Fix reference leaks in the error paths of update_bases() and __build_class__. Patch by Pablo Galindo.

  • bpo-44826: Initial implementation of adaptive specialization of STORE_ATTR

    Three specialized forms of STORE_ATTR are added:

    • STORE_ATTR_SLOT

    • STORE_ATTR_SPLIT_KEYS

    • STORE_ATTR_WITH_HINT

  • bpo-44838: Fixed a bug that was causing the parser to raise an incorrect custom SyntaxError for invalid 'if' expressions. Patch by Pablo Galindo.

  • bpo-44821: Create instance dictionaries (__dict__) eagerly, to improve regularity of object layout and assist specialization.

  • bpo-44792: Improve syntax errors for if expressions. Patch by Miguel Brito

  • bpo-34013: Generalize the invalid legacy statement custom error message (like the one generated when "print" is called without parentheses) to include more generic expressions. Patch by Pablo Galindo

  • bpo-44732: Rename types.Union to types.UnionType.

  • bpo-44725: Expose specialization stats in 哋它亢 via _opcode.get_specialization_stats().

  • bpo-44717: Improve AttributeError on circular imports of submodules.

  • bpo-44698: Fix undefined behaviour in complex object exponentiation.

  • bpo-44653: Support typing types in parameter substitution in the union type.

  • bpo-44676: Add ability to serialise types.Union objects. Patch provided by Yurii Karabas.

  • bpo-44633: Parameter substitution of the union type with wrong types now raises TypeError instead of returning NotImplemented.

  • bpo-44661: Update property_descr_set to use vectorcall if possible. Patch by Donghee Na.

  • bpo-44662: Add __module__ to types.Union. This also fixes types.Union issues with typing.Annotated. Patch provided by Yurii Karabas.

  • bpo-44655: Include the name of the type in unset __slots__ attribute errors. Patch by Pablo Galindo

  • bpo-44655: Don't include a missing attribute with the same name as the failing one when offering suggestions for missing attributes. Patch by Pablo Galindo

  • bpo-44646: Fix the hash of the union type: it no longer depends on the order of arguments.

  • bpo-44636: Collapse union of equal types. E.g. the result of int | int is now int. Fix comparison of the union type with non-hashable objects. E.g. int | str == {} no longer raises a TypeError.

  • bpo-44611: On Windows, os.urandom(): uses BCryptGenRandom API instead of CryptGenRandom API which is deprecated from Microsoft Windows API. Patch by Donghee Na.

  • bpo-44635: Convert None to type(None) in the union type constructor.

  • bpo-26280: Implement adaptive specialization for BINARY_SUBSCR

    Three specialized forms of BINARY_SUBSCR are added:

    • BINARY_SUBSCR_LIST_INT

    • BINARY_SUBSCR_TUPLE_INT

    • BINARY_SUBSCR_DICT

  • bpo-44589: Mapping patterns in match statements with two or more equal literal keys will now raise a SyntaxError at compile-time.

  • bpo-44606: Fix __instancecheck__ and __subclasscheck__ for the union type.

  • bpo-42073: The @classmethod decorator can now wrap other classmethod-like descriptors.

  • bpo-41972: Tuned the string-searching algorithm of fastsearch.h to have a shorter inner loop for most cases.

  • bpo-44590: All necessary data for executing a 哋它亢 function (local variables, stack, etc) is now kept in a per-thread stack. Frame objects are lazily allocated on demand. This increases performance by about 7% on the standard benchmark suite. Introspection and debugging are unaffected as frame objects are always available when needed. Patch by Mark Shannon.

  • bpo-44584: The threading debug (哋它亢THREADDEBUG environment variable) is deprecated in 哋它亢 3.10 and will be removed in 哋它亢 3.12. This feature requires a debug build of 哋它亢. Patch by Victor Stinner.

  • bpo-43895: An obsolete internal cache of shared object file handles added in 1995 that attempted, but did not guarantee, that a .so would not be dlopen'ed twice to work around flaws in mid-1990s posix-ish operating systems has been removed from dynload_shlib.c.

  • bpo-44490: typing now searches for type parameters in types.Union objects. get_type_hints will also properly resolve annotations with nested types.Union objects. Patch provided by Yurii Karabas.

  • bpo-43950: Code objects can now provide the column information for instructions when available. This is levaraged during traceback printing to show the expressions responsible for errors.

    Contributed by Pablo Galindo, Batuhan Taskaya and Ammar Askar as part of PEP 657.

  • bpo-44562: Remove uses of PyObject_GC_Del() in error path when initializing types.GenericAlias.

  • bpo-41486: Fix a memory consumption and copying performance regression in earlier 3.10 beta releases if someone used an output buffer larger than 4GiB with zlib.decompress on input data that expands that large.

  • bpo-43908: Heap types with the Py_TPFLAGS_IMMUTABLETYPE flag can now inherit the PEP 590 vectorcall protocol. Previously, this was only possible for static types. Patch by Erlend E. Aasland.

  • bpo-44553: Implement GC methods for types.Union to break reference cycles and prevent memory leaks.

  • bpo-44490: Add __parameters__ attribute and __getitem__ operator to types.Union. Patch provided by Yurii Karabas.

  • bpo-44523: Remove the pass-through for hash() of weakref.proxy objects to prevent unintended consequences when the original referred object dies while the proxy is part of a hashable object. Patch by Pablo Galindo.

  • bpo-44483: Fix a crash in types.Union objects when creating a union of an object with bad __module__ field.

  • bpo-44486: Modules will always have a dictionary, even when created by types.ModuleType.__new__()

  • bpo-44472: Fix ltrace functionality when exceptions are raised. Patch by Pablo Galindo

  • bpo-12022: A TypeError is now raised instead of an AttributeError in with and async with statements for objects which do not support the context manager or asynchronous context manager protocols correspondingly.

  • bpo-44297: Make sure that the line number is set when entering a comprehension scope. This ensures that backtraces including generator expressions show the correct line number.

  • bpo-44456: Improve the syntax error when mixing positional and keyword patterns. Patch by Pablo Galindo.

  • bpo-44409: Fix error location information for tokenizer errors raised on initialization of the tokenizer. Patch by Pablo Galindo.

  • bpo-44396: Fix a possible crash in the tokenizer when raising syntax errors for unclosed strings. Patch by Pablo Galindo.

  • bpo-44376: Exact integer exponentiation (like i**2 or pow(i, 2)) with a small exponent is much faster, due to reducing overhead in such cases.

  • bpo-44313: Directly imported objects and modules (through import and from import statements) don't generate LOAD_METHOD/CALL_METHOD for directly accessed objects on their namespace. They now use the regular LOAD_ATTR/CALL_FUNCTION.

  • bpo-44338: Implement adaptive specialization for LOAD_GLOBAL

    Two specialized forms of LOAD_GLOBAL are added:

    • LOAD_GLOBAL_MODULE

    • LOAD_GLOBAL_BUILTIN

  • bpo-44368: Improve syntax errors for invalid "as" targets. Patch by Pablo Galindo

  • bpo-44349: Fix an edge case when displaying text from files with encoding in syntax errors. Patch by Pablo Galindo.

  • bpo-44337: Initial implementation of adaptive specialization of LOAD_ATTR

    Four specialized forms of LOAD_ATTR are added:

    • LOAD_ATTR_SLOT

    • LOAD_ATTR_SPLIT_KEYS

    • LOAD_ATTR_WITH_HINT

    • LOAD_ATTR_MODULE

  • bpo-44335: Fix a regression when identifying incorrect characters in syntax errors. Patch by Pablo Galindo

  • bpo-43693: Computation of the offsets of cell variables is done in the compiler instead of at runtime. This reduces the overhead of handling cell and free variables, especially in the case where a variable is both an argument and cell variable.

  • bpo-44317: Improve tokenizer error with improved locations. Patch by Pablo Galindo.

  • bpo-44304: Fix a crash in the sqlite3 module that happened when the garbage collector clears sqlite.Statement objects. Patch by Pablo Galindo

  • bpo-44305: Improve error message for try blocks without except or finally blocks. Patch by Pablo Galindo.

  • bpo-43413: Constructors of subclasses of some builtin classes (e.g. tuple, list, frozenset) no longer accept arbitrary keyword arguments. [reverted in 3.11a4] Subclass of set can now define a __new__() method with additional keyword parameters without overriding also __init__().

  • bpo-43667: Improve Unicode support in non-UTF locales on Oracle Solaris. This issue does not affect other Solaris systems.

  • bpo-43693: A new opcode MAKE_CELL has been added that effectively moves some of the work done on function entry into the compiler and into the eval loop. In addition to creating the required cell objects, the new opcode converts relevant arguments (and other locals) to cell variables on function entry.

  • bpo-44232: Fix a regression in type() when a metaclass raises an exception. The C function type_new() must properly report the exception when a metaclass constructor raises an exception and the winner class is not the metaclass. Patch by Victor Stinner.

  • bpo-44201: Avoid side effects of checking for specialized syntax errors in the REPL that was causing it to ask for extra tokens after a syntax error had been detected. Patch by Pablo Galindo

  • bpo-43693: PyCodeObject gained co_fastlocalnames and co_fastlocalkinds as the authoritative source of fast locals info. Marshaled code objects have changed accordingly.

  • bpo-44184: Fix a crash at 哋它亢 exit when a deallocator function removes the last strong reference to a heap type. Patch by Victor Stinner.

  • bpo-44187: Implement quickening in the interpreter. This offers no advantages as yet, but is an enabler of future optimizations. See PEP 659 for full explanation.

  • bpo-44180: The parser doesn't report generic syntax errors that happen in a position further away that the one it reached in the first pass. Patch by Pablo Galindo

  • bpo-44168: Fix error message in the parser involving keyword arguments with invalid expressions. Patch by Pablo Galindo

  • bpo-44156: String caches in compile.c are now subinterpreter compatible.

  • bpo-44143: Fixed a crash in the parser that manifest when raising tokenizer errors when an existing exception was present. Patch by Pablo Galindo.

  • bpo-44032: Move 'fast' locals and other variables from the frame object to a per-thread datastack.

  • bpo-44114: Fix incorrect dictkeys_reversed and dictitems_reversed function signatures in C code, which broke webassembly builds.

  • bpo-44110: Improve str.__getitem__() error message

  • bpo-26110: Add CALL_METHOD_KW opcode to speed up method calls with keyword arguments. Idea originated from PyPy. A side effect is executing CALL_METHOD is now branchless in the evaluation loop.

  • bpo-28307: Compiler now optimizes simple C-style formatting with literal format containing only format codes %s, %r and %a by converting them to f-string expressions.

  • bpo-43149: Correct the syntax error message regarding multiple exception types to not refer to "exception groups". Patch by Pablo Galindo

  • bpo-43822: The parser will prioritize tokenizer errors over custom syntax errors when raising exceptions. Patch by Pablo Galindo.

  • bpo-40222: "Zero cost" exception handling.

    • Uses a lookup table to determine how to handle exceptions.

    • Removes SETUP_FINALLY and POP_TOP block instructions, eliminating the runtime overhead of try statements.

    • Reduces the size of the frame object by about 60%.

    Patch by Mark Shannon

  • bpo-43918: Document the signature and default argument in the docstring of the new anext builtin.

  • bpo-43833: Emit a deprecation warning if the numeric literal is immediately followed by one of keywords: and, else, for, if, in, is, or. Raise a syntax error with more informative message if it is immediately followed by other keyword or identifier.

  • bpo-43879: Add native_thread_id to PyThreadState. Patch by Gabriele N. Tornetta.

  • bpo-43693: Compute cell offsets relative to locals in compiler. Allows the interpreter to treats locals and cells a single array, which is slightly more efficient. Also make the LOAD_CLOSURE opcode an alias for LOAD_FAST. Preserving LOAD_CLOSURE helps keep bytecode a bit more readable.

  • bpo-17792: More accurate error messages for access of unbound locals or free vars.

  • bpo-28146: Fix a confusing error message in str.format().

  • bpo-11105: When compiling ast.AST objects with recursive references through compile(), the interpreter doesn't crash anymore instead it raises a RecursionError.

  • bpo-39091: Fix crash when using passing a non-exception to a generator's throw() method. Patch by Noah Oxer

  • bpo-33346: Asynchronous comprehensions are now allowed inside comprehensions in asynchronous functions. Outer comprehensions implicitly become asynchronous.

Library

  • bpo-45371: Fix clang rpath issue in distutils. The UnixCCompiler now uses correct clang option to add a runtime library directory (rpath) to a shared library.

  • bpo-45329: Fix freed memory access in pyexpat.xmlparser when building it with an installed expat library <= 2.2.0.

  • bpo-41710: On Unix, if the sem_clockwait() function is available in the C library (glibc 2.30 and newer), the threading.Lock.acquire() method now uses the monotonic clock (time.CLOCK_MONOTONIC) for the timeout, rather than using the system clock (time.CLOCK_REALTIME), to not be affected by system clock changes. Patch by Victor Stinner.

  • bpo-1596321: Fix the threading._shutdown() function when the threading module was imported first from a thread different than the main thread: no longer log an error at 哋它亢 exit.

  • bpo-45274: Fix a race condition in the Thread.join() method of the threading module. If the function is interrupted by a signal and the signal handler raises an exception, make sure that the thread remains in a consistent state to prevent a deadlock. Patch by Victor Stinner.

  • bpo-21302: In Unix operating systems, time.sleep() now uses the nanosleep() function, if clock_nanosleep() is not available but nanosleep() is available. nanosleep() allows to sleep with nanosecond precision.

  • bpo-21302: On Windows, time.sleep() now uses a waitable timer which has a resolution of 100 nanoseconds (10-7 seconds). Previously, it had a resolution of 1 millisecond (10-3 seconds). Patch by Benjamin Szőke and Victor Stinner.

  • bpo-45238: Fix unittest.IsolatedAsyncioTestCase.debug(): it runs now asynchronous methods and callbacks.

  • bpo-36674: unittest.TestCase.debug() raises now a unittest.SkipTest if the class or the test method are decorated with the skipping decorator.

  • bpo-45235: Fix an issue where argparse would not preserve values in a provided namespace when using a subparser with defaults.

  • bpo-45183: Have zipimport.zipimporter.find_spec() not raise an exception when the underlying zip file has been deleted and the internal cache has been reset via invalidate_cache().

  • bpo-45234: Fixed a regression in copyfile(), copy(), copy2() raising FileNotFoundError when source is a directory, which should raise IsADirectoryError

  • bpo-45228: Fix stack buffer overflow in parsing J1939 network address.

  • bpo-45225: use map function instead of genexpr in capwords.

  • bpo-42135: Fix typo: importlib.find_loader is really slated for removal in 哋它亢 3.12 not 3.10, like the others in PR 25169.

    Patch by Hugo van Kemenade.

  • bpo-20524: Improves error messages on .format() operation for str, float, int, and complex. New format now shows the problematic pattern and the object type.

  • bpo-45168: Change dis.dis() output to omit op arg values that cannot be resolved due to co_consts, co_names etc not being provided. Previously the oparg itself was repeated in the value field, which is not useful and can be confusing.

  • bpo-21302: In Unix operating systems, time.sleep() now uses the clock_nanosleep() function, if available, which allows to sleep for an interval specified with nanosecond precision.

  • bpo-45173: Remove from the configparser module: the SafeConfigParser class, the filename property of the ParsingError class, the readfp() method of the ConfigParser class, deprecated since 哋它亢 3.2.

    Patch by Hugo van Kemenade.

  • bpo-44987: Pure ASCII strings are now normalized in constant time by unicodedata.normalize(). Patch by Donghee Na.

  • bpo-35474: Calling mimetypes.guess_all_extensions() with strict=False no longer affects the result of the following call with strict=True. Also, mutating the returned list no longer affects the global state.

  • bpo-45166: typing.get_type_hints() now works with Final wrapped in ForwardRef.

  • bpo-45162: Remove many old deprecated unittest features:

    • "fail*" and "assert*" aliases of TestCase methods.

    • Broken from start TestCase method assertDictContainsSubset().

    • Ignored <unittest.TestLoader.loadTestsFromModule> TestLoader.loadTestsFromModule() parameter use_load_tests.

    • Old alias _TextTestResult of TextTestResult.

  • bpo-38371: Remove the deprecated split() method of _tkinter.TkappType. Patch by Erlend E. Aasland.

  • bpo-20499: Improve the speed and accuracy of statistics.pvariance().

  • bpo-45132: Remove __getitem__() methods of xml.dom.pulldom.DOMEventStream, wsgiref.util.FileWrapper and fileinput.FileInput, deprecated since 哋它亢 3.9.

    Patch by Hugo van Kemenade.

  • bpo-45129: Due to significant security concerns, the reuse_address parameter of asyncio.loop.create_datagram_endpoint(), disabled in 哋它亢 3.9, is now entirely removed. This is because of the behavior of the socket option SO_REUSEADDR in UDP.

    Patch by Hugo van Kemenade.

  • bpo-45124: The bdist_msi command, deprecated in 哋它亢 3.9, is now removed.

    Use bdist_wheel (wheel packages) instead.

    Patch by Hugo van Kemenade.

  • bpo-30856: unittest.TestResult methods addFailure(), addError(), addSkip() and addSubTest() are now called immediately after raising an exception in test or finishing a subtest. Previously they were called only after finishing the test clean up.

  • bpo-45034: Changes how error is formatted for struct.pack with 'H' and 'h' modes and too large / small numbers. Now it shows the actual numeric limits, while previously it was showing arithmetic expressions.

  • bpo-25894: unittest now always reports skipped and failed subtests separately: separate characters in default mode and separate lines in verbose mode. Also the test description is now output for errors in test method, class and module cleanups.

  • bpo-45081: Fix issue when dataclasses that inherit from typing.Protocol subclasses have wrong __init__. Patch provided by Yurii Karabas.

  • bpo-45085: The binhex module, deprecated in 哋它亢 3.9, is now removed. The following binascii functions, deprecated in 哋它亢 3.9, are now also removed:

    • a2b_hqx(), b2a_hqx();

    • rlecode_hqx(), rledecode_hqx().

    The binascii.crc_hqx() function remains available.

    Patch by Victor Stinner.

  • bpo-40360: The lib2to3 package is now deprecated and may not be able to parse 哋它亢 3.10 or newer. See the PEP 617 (New PEG parser for C哋它亢). Patch by Victor Stinner.

  • bpo-45075: Rename traceback.StackSummary.format_frame() to traceback.StackSummary.format_frame_summary(). This method was added for 3.11 so it was not released yet.

    Updated code and docs to better distinguish frame and FrameSummary.

  • bpo-31299: Add option to completely drop frames from a traceback by returning None from a format_frame() override.

  • bpo-41620: run() now always return a TestResult instance. Previously it returned None if the test class or method was decorated with a skipping decorator.

  • bpo-45021: Fix a potential deadlock at shutdown of forked children when using concurrent.futures module

  • bpo-43913: Fix bugs in cleaning up classes and modules in unittest:

    • Functions registered with addModuleCleanup() were not called unless the user defines tearDownModule() in their test module.

    • Functions registered with addClassCleanup() were not called if tearDownClass is set to None.

    • Buffering in TestResult did not work with functions registered with addClassCleanup() and addModuleCleanup().

    • Errors in functions registered with addClassCleanup() and addModuleCleanup() were not handled correctly in buffered and debug modes.

    • Errors in setUpModule() and functions registered with addModuleCleanup() were reported in wrong order.

    • And several lesser bugs.

  • bpo-45030: Fix integer overflow in pickling and copying the range iterator.

  • bpo-45001: Made email date parsing more robust against malformed input, namely a whitespace-only Date: header. Patch by Wouter Bolsterlee.

  • bpo-45010: Remove support of special method __div__ in unittest.mock. It is not used in 哋它亢 3.

  • bpo-39218: Improve accuracy of variance calculations by using x*x instead of x**2.

  • bpo-43613: Improve the speed of gzip.compress() and gzip.decompress() by compressing and decompressing at once in memory instead of in a streamed fashion.

  • bpo-37596: Ensure that set and frozenset objects are always marshalled reproducibly.

  • bpo-44019: A new function operator.call has been added, such that operator.call(obj, *args, **kwargs) == obj(*args, **kwargs).

  • bpo-42255: webbrowser.MacOSX is deprecated and will be removed in 哋它亢 3.13. It is untested and undocumented and also not used by webbrowser itself. Patch by Donghee Na.

  • bpo-44955: Method stopTestRun() is now always called in pair with method startTestRun() for TestResult objects implicitly created in run(). Previously it was not called for test methods and classes decorated with a skipping decorator.

  • bpo-39039: tarfile.open raises ReadError when a zlib error occurs during file extraction.

  • bpo-44935: subprocess on Solaris now also uses os.posix_spawn() for better performance.

  • bpo-44911: IsolatedAsyncioTestCase will no longer throw an exception while cancelling leaked tasks. Patch by Bar Harel.

  • bpo-41322: Added DeprecationWarning for tests and async tests that return a value!=None (as this may indicate an improperly written test, for example a test written as a generator function).

  • bpo-44524: Make exception message more useful when subclass from typing special form alias. Patch provided by Yurii Karabas.

  • bpo-38956: argparse.BooleanOptionalAction's default value is no longer printed twice when used with argparse.ArgumentDefaultsHelpFormatter.

  • bpo-44860: Fix the posix_user scheme in sysconfig to not depend on sys.platlibdir.

  • bpo-44859: Improve error handling in sqlite3 and raise more accurate exceptions.

    • MemoryError is now raised instead of sqlite3.Warning when memory is not enough for encoding a statement to UTF-8 in Connection.__call__() and Cursor.execute().

    • UnicodEncodeError is now raised instead of sqlite3.Warning when the statement contains surrogate characters in Connection.__call__() and Cursor.execute().

    • TypeError is now raised instead of ValueError for non-string script argument in Cursor.executescript().

    • ValueError is now raised for script containing the null character instead of truncating it in Cursor.executescript().

    • Correctly handle exceptions raised when getting boolean value of the result of the progress handler.

    • Add many tests covering different corner cases.

  • bpo-44581: Upgrade bundled pip to 21.2.3 and setuptools to 57.4.0

  • bpo-44849: Fix the os.set_inheritable() function on FreeBSD 14 for file descriptor opened with the O_PATH flag: ignore the EBADF error on ioctl(), fallback on the fcntl() implementation. Patch by Victor Stinner.

  • bpo-44605: The @functools.total_ordering() decorator now works with metaclasses.

  • bpo-44524: Fixed an issue wherein the __name__ and __qualname__ attributes of subscribed specialforms could be None.

  • bpo-44839: MemoryError raised in user-defined functions will now produce a MemoryError in sqlite3. OverflowError will now be converted to DataError. Previously OperationalError was produced in these cases.

  • bpo-44822: sqlite3 user-defined functions and aggregators returning strings with embedded NUL characters are no longer truncated. Patch by Erlend E. Aasland.

  • bpo-44801: Ensure that the ParamSpec variable in Callable can only be substituted with a parameters expression (a list of types, an ellipsis, ParamSpec or Concatenate).

  • bpo-44806: Non-protocol subclasses of typing.Protocol ignore now the __init__ method inherited from protocol base classes.

  • bpo-27275: collections.OrderedDict.popitem() and collections.OrderedDict.pop() no longer call __getitem__ and __delitem__ methods of the OrderedDict subclasses.

  • bpo-44793: Fix checking the number of arguments when subscribe a generic type with ParamSpec parameter.

  • bpo-44784: In importlib.metadata tests, override warnings behavior under expected DeprecationWarnings (importlib_metadata 4.6.3).

  • bpo-44667: The tokenize.tokenize() doesn't incorrectly generate a NEWLINE token if the source doesn't end with a new line character but the last line is a comment, as the function is already generating a NL token. Patch by Pablo Galindo

  • bpo-44771: Added importlib.simple module implementing adapters from a low-level resources reader interface to a TraversableResources interface. Legacy API (path, contents, ...) is now supported entirely by the .files() API with a compatibility shim supplied for resource loaders without that functionality. Feature parity with importlib_resources 5.2.

  • bpo-44752: rcompleter does not call getattr() on property objects to avoid the side-effect of evaluating the corresponding method.

  • bpo-44747: Refactor usage of sys._getframe in typing module. Patch provided by Yurii Karabas.

  • bpo-42378: Fixes the issue with log file being overwritten when logging.FileHandler is used in atexit with filemode set to 'w'. Note this will cause the message in atexit not being logged if the log stream is already closed due to shutdown of logging.

  • bpo-44720: weakref.proxy objects referencing non-iterators now raise TypeError rather than dereferencing the null tp_iternext slot and crashing.

  • bpo-44704: The implementation of collections.abc.Set._hash() now matches that of frozenset.__hash__().

  • bpo-44666: Fixed issue in compileall.compile_file() when sys.stdout is redirected. Patch by Stefan Hölzl.

  • bpo-44688: sqlite3.Connection.create_collation() now accepts non-ASCII collation names. Patch by Erlend E. Aasland.

  • bpo-44690: Adopt binacii.a2b_base64's strict mode in base64.b64decode.

  • bpo-42854: Fixed a bug in the _ssl module that was throwing OverflowError when using _ssl._SSLSocket.write() and _ssl._SSLSocket.read() for a big value of the len parameter. Patch by Pablo Galindo.

  • bpo-44686: Replace unittest.mock._importer with pkgutil.resolve_name.

  • bpo-44353: Make NewType.__call__ faster by implementing it in C. Patch provided by Yurii Karabas.

  • bpo-44682: Change the pdb commands directive to disallow setting commands for an invalid breakpoint and to display an appropriate error.

  • bpo-44353: Refactor typing.NewType from function into callable class. Patch provided by Yurii Karabas.

  • bpo-44678: Added a separate error message for discontinuous padding in binascii.a2b_base64 strict mode.

  • bpo-44524: Add missing __name__ and __qualname__ attributes to typing module classes. Patch provided by Yurii Karabas.

  • bpo-40897: Give priority to using the current class constructor in inspect.signature(). Patch by Weipeng Hong.

  • bpo-44638: Add a reference to the zipp project and hint as to how to use it.

  • bpo-44648: Fixed wrong error being thrown by inspect.getsource() when examining a class in the interactive session. Instead of TypeError, it should be OSError with appropriate error message.

  • bpo-44608: Fix memory leak in _tkinter._flatten() if it is called with a sequence or set, but not list or tuple.

  • bpo-44594: Fix an edge case of ExitStack and AsyncExitStack exception chaining. They will now match with block behavior when __context__ is explicitly set to None when the exception is in flight.

  • bpo-42799: In fnmatch, the cache size for compiled regex patterns (functools.lru_cache()) was bumped up from 256 to 32768, affecting functions: fnmatch.fnmatch(), fnmatch.fnmatchcase(), fnmatch.filter().

  • bpo-41928: Update shutil.copyfile() to raise FileNotFoundError instead of confusing IsADirectoryError when a path ending with a os.path.sep does not exist; shutil.copy() and shutil.copy2() are also affected.

  • bpo-44569: Added the StackSummary.format_frame() function in traceback. This allows users to customize the way individual lines are formatted in tracebacks without re-implementing logic to handle recursive tracebacks.

  • bpo-44566: handle StopIteration subclass raised from @contextlib.contextmanager generator

  • bpo-44558: Make the implementation consistency of indexOf() between C and 哋它亢 versions. Patch by Donghee Na.

  • bpo-41249: Fixes TypedDict to work with typing.get_type_hints() and postponed evaluation of annotations across modules.

  • bpo-44554: Refactor argument processing in pdb.main() to simplify detection of errors in input loading and clarify behavior around module or script invocation.

  • bpo-34798: Break up paragraph about pprint.PrettyPrinter construction parameters to make it easier to read.

  • bpo-44539: Added support for recognizing JPEG files without JFIF or Exif markers.

  • bpo-44461: Fix bug with pdb's handling of import error due to a package which does not have a __main__ module

  • bpo-43625: Fix a bug in the detection of CSV file headers by csv.Sniffer.has_header() and improve documentation of same.

  • bpo-44516: Update vendored pip to 21.1.3

  • bpo-42892: Fixed an exception thrown while parsing a malformed multipart email by email.message.EmailMessage.

  • bpo-44468: typing.get_type_hints() now finds annotations in classes and base classes with unexpected __module__. Previously, it skipped those MRO elements.

  • bpo-44491: Allow clearing the sqlite3 authorizer callback by passing None to set_authorizer(). Patch by Erlend E. Aasland.

  • bpo-43977: Set the proper Py_TPFLAGS_MAPPING and Py_TPFLAGS_SEQUENCE flags for subclasses created before a parent has been registered as a collections.abc.Mapping or collections.abc.Sequence.

  • bpo-44482: Fix very unlikely resource leak in glob in alternate 哋它亢 implementations.

  • bpo-44466: The faulthandler module now detects if a fatal error occurs during a garbage collector collection. Patch by Victor Stinner.

  • bpo-44471: A TypeError is now raised instead of an AttributeError in contextlib.ExitStack.enter_context() and contextlib.AsyncExitStack.enter_async_context() for objects which do not support the context manager or asynchronous context manager protocols correspondingly.

  • bpo-44404: tkinter's after() method now supports callables without the __name__ attribute.

  • bpo-41546: Make pprint (like the builtin print) not attempt to write to stdout when it is None.

  • bpo-44458: BUFFER_BLOCK_SIZE is now declared static, to avoid linking collisions when bz2, lmza or zlib are statically linked.

  • bpo-44464: Remove exception for flake8 in deprecated importlib.metadata interfaces. Sync with importlib_metadata 4.6.

  • bpo-44446: Take into account that lineno might be None in traceback.FrameSummary.

  • bpo-44439: Fix in bz2.BZ2File.write() / lzma.LZMAFile.write() methods, when the input data is an object that supports the buffer protocol, the file length may be wrong.

  • bpo-44434: _thread.start_new_thread() no longer calls PyThread_exit_thread() explicitly at the thread exit, the call was redundant. On Linux with the glibc, pthread_exit() aborts the whole process if dlopen() fails to open libgcc_s.so file (ex: EMFILE error). Patch by Victor Stinner.

  • bpo-42972: The _thread.RLock type now fully implement the GC protocol: add a traverse function and the Py_TPFLAGS_HAVE_GC flag. Patch by Victor Stinner.

  • bpo-44422: The threading.enumerate() function now uses a reentrant lock to prevent a hang on reentrant call. Patch by Victor Stinner.

  • bpo-38291: Importing typing.io or typing.re now prints a DeprecationWarning.

  • bpo-37880: argparse actions store_const and append_const each receive a default value of None when the const kwarg is not provided. Previously, this raised a TypeError.

  • bpo-44389: Fix deprecation of ssl.OP_NO_TLSv1_3

  • bpo-27827: pathlib.PureWindowsPath.is_reserved() now identifies a greater range of reserved filenames, including those with trailing spaces or colons.

  • bpo-44395: Fix as_string() to pass unixfrom properly. Patch by Donghee Na.

  • bpo-34266: Handle exceptions from parsing the arg of pdb's run/restart command.

  • bpo-44362: Improve ssl module's deprecation messages, error reporting, and documentation for deprecations.

  • bpo-44342: [Enum] Change pickling from by-value to by-name.

  • bpo-44356: [Enum] Allow multiple data-type mixins if they are all the same.

  • bpo-44351: Restore back parse_makefile() in distutils.sysconfig because it behaves differently than the similar implementation in sysconfig.

  • bpo-35800: smtpd.MailmanProxy is now removed as it is unusable without an external module, mailman. Patch by Donghee Na.

  • bpo-44357: Added a function that returns cube root of the given number math.cbrt()

  • bpo-44339: Change math.pow(±0.0, -math.inf) to return inf instead of raising ValueError. This brings the special-case handling of math.pow into compliance with the IEEE 754 standard.

  • bpo-44242: Remove missing flag check from Enum creation and move into a verify decorator.

  • bpo-44246: In importlib.metadata, restore compatibility in the result from Distribution.entry_points (EntryPoints) to honor expectations in older implementations and issuing deprecation warnings for these cases: A. EntryPoints objects are once again mutable, allowing for sort() and other list-based mutation operations. Avoid deprecation warnings by casting to a mutable sequence (e.g. list(dist.entry_points).sort()). B. EntryPoints results once again allow for access by index. To avoid deprecation warnings, cast the result to a Sequence first (e.g. tuple(dist.entry_points)[0]).

  • bpo-44246: In importlib.metadata.entry_points, de-duplication of distributions no longer requires loading the full metadata for PathDistribution objects, improving entry point loading performance by ~10x.

  • bpo-43858: Added a function that returns a copy of a dict of logging levels: logging.getLevelNamesMapping()

  • bpo-44260: The random.Random constructor no longer reads system entropy without need.

  • bpo-44254: On Mac, give turtledemo button text a color that works on both light or dark background. Programmers cannot control the latter.

  • bpo-44258: Support PEP 515 for Fraction's initialization from string.

  • bpo-44235: Remove deprecated functions in the gettext. Patch by Donghee Na.

  • bpo-38693: Prefer f-strings to .format in importlib.resources.

  • bpo-33693: Importlib.metadata now prefers f-strings to .format.

  • bpo-44241: Incorporate minor tweaks from importlib_metadata 4.1: SimplePath protocol, support for Metadata 2.2.

  • bpo-43216: Remove the @asyncio.coroutine decorator enabling legacy generator-based coroutines to be compatible with async/await code; remove asyncio.coroutines.CoroWrapper used for wrapping legacy coroutine objects in the debug mode. The decorator has been deprecated since 哋它亢 3.8 and the removal was initially scheduled for 哋它亢 3.10. Patch by Illia Volochii.

  • bpo-44210: Make importlib.metadata._meta.PackageMetadata public.

  • bpo-43643: Declare readers.MultiplexedPath.name as a property per the spec.

  • bpo-27334: The sqlite3 context manager now performs a rollback (thus releasing the database lock) if commit failed. Patch by Luca Citi and Erlend E. Aasland.

  • bpo-4928: Documented existing behavior on POSIX: NamedTemporaryFiles are not deleted when creating process is killed with SIGKILL

  • bpo-44154: Optimize fractions.Fraction pickling for large components.

  • bpo-33433: For IPv4 mapped IPv6 addresses (RFC 4291 Section 2.5.5.2), the ipaddress.IPv6Address.is_private check is deferred to the mapped IPv4 address. This solves a bug where public mapped IPv4 addresses were considered private by the IPv6 check.

  • bpo-44150: Add optional weights argument to statistics.fmean().

  • bpo-44142: ast.unparse() will now drop the redundant parentheses when tuples used as assignment targets (e.g in for loops).

  • bpo-44145: hmac computations were not releasing the GIL while calling the OpenSSL HMAC_Update C API (a new feature in 3.9). This unintentionally prevented parallel computation as other hashlib algorithms support.

  • bpo-44095: zipfile.Path now supports zipfile.Path.stem, zipfile.Path.suffixes, and zipfile.Path.suffix attributes.

  • bpo-44077: It's now possible to receive the type of service (ToS), a.k.a. differentiated services (DS), a.k.a. differentiated services code point (DSCP) and explicit congestion notification (ECN) IP header fields with socket.IP_RECVTOS.

  • bpo-37788: Fix a reference leak when a Thread object is never joined.

  • bpo-38908: Subclasses of typing.Protocol which only have data variables declared will now raise a TypeError when checked with isinstance unless they are decorated with runtime_checkable(). Previously, these checks passed silently. Patch provided by Yurii Karabas.

  • bpo-44098: typing.ParamSpec will no longer be found in the __parameters__ of most typing generics except in valid use locations specified by PEP 612. This prevents incorrect usage like typing.List[P][int]. This change means incorrect usage which may have passed silently in 3.10 beta 1 and earlier will now error.

  • bpo-44089: Allow subclassing csv.Error in 3.10 (it was allowed in 3.9 and earlier but was disallowed in early versions of 3.10).

  • bpo-44081: ast.unparse() now doesn't use redundant spaces to separate lambda and the : if there are no parameters.

  • bpo-44061: Fix regression in previous release when calling pkgutil.iter_modules() with a list of pathlib.Path objects

  • bpo-44059: Register the SerenityOS Browser in the webbrowser module.

  • bpo-36515: The hashlib module no longer does unaligned memory accesses when compiled for ARM platforms.

  • bpo-40465: Remove random module features deprecated in 哋它亢 3.9.

  • bpo-44018: random.seed() no longer mutates bytearray inputs.

  • bpo-38352: Add IO, BinaryIO, TextIO, Match, and Pattern to typing.__all__. Patch by Jelle Zijlstra.

  • bpo-44002: urllib.parse now uses functool.lru_cache() for its internal URL splitting and quoting caches instead of rolling its own like its the '90s.

    The undocumented internal urllib.parse Quoted class API is now deprecated, for removal in 3.14.

  • bpo-43972: When http.server.SimpleHTTPRequestHandler sends a 301 (Moved Permanently) for a directory path not ending with /, add a Content-Length: 0 header. This improves the behavior for certain clients.

  • bpo-28528: Fix a bug in pdb where checkline() raises AttributeError if it is called after reset().

  • bpo-43853: Improved string handling for sqlite3 user-defined functions and aggregates:

    • It is now possible to pass strings with embedded null characters to UDFs

    • Conversion failures now correctly raise MemoryError

    Patch by Erlend E. Aasland.

  • bpo-43666: AIX: Lib/_aix_support.get_platform() may fail in an AIX WPAR. The fileset bos.rte appears to have a builddate in both LPAR and WPAR so this fileset is queried rather than bos.mp64. To prevent a similar situation (no builddate in ODM) a value (9988) sufficient for completing a build is provided. Patch by M Felt.

  • bpo-43650: Fix MemoryError in shutil.unpack_archive() which fails inside shutil._unpack_zipfile() on large files. Patch by Igor Bolshakov.

  • bpo-43612: zlib.compress() now accepts a wbits parameter which allows users to compress data as a raw deflate block without zlib headers and trailers in one go. Previously this required instantiating a zlib.compressobj. It also provides a faster alternative to gzip.compress when wbits=31 is used.

  • bpo-43392: importlib._bootstrap._find_and_load() now implements a two-step check to avoid locking when modules have been already imported and are ready. This improves performance of repeated calls to importlib.import_module() and importlib.__import__().

  • bpo-43318: Fix a bug where pdb does not always echo cleared breakpoints.

  • bpo-43234: Prohibit passing non-concurrent.futures.ThreadPoolExecutor executors to loop.set_default_executor() following a deprecation in 哋它亢 3.8. Patch by Illia Volochii.

  • bpo-43232: Prohibit previously deprecated potentially disruptive operations on asyncio.trsock.TransportSocket. Patch by Illia Volochii.

  • bpo-30077: Added support for Apple's aifc/sowt pseudo-compression

  • bpo-42971: Add definition of errno.EQFULL for platforms that define this constant (such as macOS).

  • bpo-43086: Added a new optional strict_mode parameter to binascii.a2b_base64. When scrict_mode is set to True, the a2b_base64 function will accept only valid base64 content. More details about what "valid base64 content" is, can be found in the function's documentation.

  • bpo-43024: Improve the help signature of traceback.print_exception(), traceback.format_exception() and traceback.format_exception_only().

  • bpo-33809: Add the traceback.TracebackException.print() method which prints the formatted exception information.

  • bpo-42862: sqlite3 now utilizes functools.lru_cache() to implement the connection statement cache. As a small optimisation, the default statement cache size has been increased from 100 to 128. Patch by Erlend E. Aasland.

  • bpo-41818: Soumendra Ganguly: add termios.tcgetwinsize(), termios.tcsetwinsize().

  • bpo-40497: subprocess.check_output() now raises ValueError when the invalid keyword argument check is passed by user code. Previously such use would fail later with a TypeError. Patch by Rémi Lapeyre.

  • bpo-37449: ensurepip now uses importlib.resources.files() traversable APIs

  • bpo-40956: Use Argument Clinic in sqlite3. Patches by Erlend E. Aasland.

  • bpo-41730: DeprecationWarning is now raised when importing tkinter.tix, which has been deprecated in documentation since 哋它亢 3.6.

  • bpo-20684: Remove unused _signature_get_bound_param function from inspect - by Anthony Sottile.

  • bpo-41402: Fix email.message.EmailMessage.set_content() when called with binary data and 7bit content transfer encoding.

  • bpo-32695: The compresslevel and preset keyword arguments of tarfile.open() are now both documented and tested.

  • bpo-41137: Use utf-8 encoding while reading .pdbrc files. Patch by Srinivas Reddy Thatiparthy

  • bpo-24391: Improved reprs of threading synchronization objects: Semaphore, BoundedSemaphore, Event and Barrier.

  • bpo-5846: Deprecated the following unittest functions, scheduled for removal in 哋它亢 3.13:

    • findTestCases()

    • makeSuite()

    • getTestCaseNames()

    Use TestLoader methods instead:

    Patch by Erlend E. Aasland.

  • bpo-40563: Support pathlike objects on dbm/shelve. Patch by Hakan Çelik and Henry-Joseph Audéoud.

  • bpo-34990: Fixed a Y2k38 bug in the compileall module where it would fail to compile files with a modification time after the year 2038.

  • bpo-39549: Whereas the code for reprlib.Repr had previously used a hardcoded string value of '...', this PR updates it to use of a “fillvalue” attribute, whose value defaults to '...' and can be reset in either individual reprlib.Repr instances or in subclasses thereof.

  • bpo-37022: pdb now displays exceptions from repr() with its p and pp commands.

  • bpo-38840: Fix test___all__ on platforms lacking a shared memory implementation.

  • bpo-39359: Add one missing check that the password is a bytes object for an encrypted zipfile.

  • bpo-38741: configparser: using ']' inside a section header will no longer cut the section name short at the ']'

  • bpo-38415: Added missing behavior to contextlib.asynccontextmanager() to match contextlib.contextmanager() so decorated functions can themselves be decorators.

  • bpo-30256: Pass multiprocessing BaseProxy argument manager_owned through AutoProxy.

  • bpo-27513: email.utils.getaddresses() now accepts email.header.Header objects along with string values. Patch by Zackery Spytz.

  • bpo-16379: Add SQLite error code and name to sqlite3 exceptions. Patch by Aviv Palivoda, Daniel Shahaf, and Erlend E. Aasland.

  • bpo-26228: pty.spawn no longer hangs on FreeBSD, macOS, and Solaris.

  • bpo-33349: lib2to3 now recognizes async generators everywhere.

  • bpo-29298: Fix TypeError when required subparsers without dest do not receive arguments. Patch by Anthony Sottile.

Documentation

  • bpo-45216: Remove extra documentation listing methods in difflib. It was rendering twice in pydoc and was outdated in some places.

  • bpo-45024: collections.abc documentation has been expanded to explicitly cover how instance and subclass checks work, with additional doctest examples and an exhaustive list of ABCs which test membership purely by presence of the right special methods. Patch by Raymond Hettinger.

  • bpo-44957: Promote PEP 604 union syntax by using it where possible. Also, mention X | Y more prominently in section about Union and mention X | None at all in section about Optional.

  • bpo-16580: Added code equivalents for the int.to_bytes() and int.from_bytes() methods, as well as tests ensuring that these code equivalents are valid.

  • bpo-44903: Removed the othergui.rst file, any references to it, and the list of GUI frameworks in the FAQ. In their place I've added links to the 哋它亢 Wiki