3.15.0a7 - Cpython — ContextQMD

.. date: 2026-03-10-09-46-44 .. gh-issue: 145731 .. nonce: 5uEGgb .. release date: 2026-03-10 .. section: Windows

Fix negative timestamp during DST on Windows. Patch by Hugo van Kemenade.

.. date: 2026-02-27-10-57-20 .. gh-issue: 145307 .. nonce: ueoT7j .. section: Windows

Defers loading of the psapi.dll module until it is used by :func:ctypes.util.dllist.

.. date: 2026-02-13-11-07-51 .. gh-issue: 144551 .. nonce: ENtMYD .. section: Windows

Updated bundled version of OpenSSL to 3.5.5.

.. date: 2026-03-04-17-39-15 .. gh-issue: 144741 .. nonce: 0RHhBF .. section: Tests

Fix test_frame_pointer_unwind when Python is built with :option:--enable-shared. Classify also libpython frames as "python". Patch by Victor Stinner.

.. date: 2026-02-12-12-12-00 .. gh-issue: 144739 .. nonce: -fx1tN .. section: Tests

When Python was compiled with system expat older then 2.7.2 but tests run with newer expat, still skip :class:!test.test_pyexpat.MemoryProtectionTest.

.. date: 2026-03-04-18-59-17 .. gh-issue: 145506 .. nonce: 6hwvEh .. section: Security

Fixes :cve:2026-2297 by ensuring that SourcelessFileLoader uses :func:io.open_code when opening .pyc files.

.. date: 2026-01-31-21-56-54 .. gh-issue: 144370 .. nonce: fp9m8t .. section: Security

Disallow usage of control characters in status in :mod:wsgiref.handlers to prevent HTTP header injections. Patch by Benedikt Johannes.

.. date: 2026-03-07-15-00-00 .. gh-issue: 145623 .. nonce: 2Y7LzT .. section: Library

Fix crash in :mod:struct when calling :func:repr or __sizeof__() on an uninitialized :class:struct.Struct object created via Struct.__new__() without calling __init__().

.. date: 2026-03-05-19-01-28 .. gh-issue: 145551 .. nonce: gItPRl .. section: Library

Fix InvalidStateError when cancelling process created by :func:asyncio.create_subprocess_exec or :func:asyncio.create_subprocess_shell. Patch by Daan De Meyer.

.. date: 2026-03-05-16-06-09 .. gh-issue: 141510 .. nonce: dFPAQS .. section: Library

:mod:marshal now supports :class:frozendict objects. The marshal format version was increased to 6. Patch by Victor Stinner.

.. date: 2026-03-03-11-49-44 .. gh-issue: 145417 .. nonce: m_HxIL .. section: Library

:mod:venv: Prevent incorrect preservation of SELinux context when copying the Activate.ps1 script. The script inherited the SELinux security context of the system template directory, rather than the destination project directory.

.. date: 2026-03-02-20-08-09 .. gh-issue: 145335 .. nonce: lVTBvd .. section: Library

os.listdir(-1) and os.scandir(-1) now fail with OSError(errno.EBADF) rather than listing the current directory. os.listxattr(-1) now fails with OSError(errno.EBADF) rather than listing extended attributes of the current directory. Patch by Victor Stinner.

.. date: 2026-03-02-19-41-39 .. gh-issue: 145376 .. nonce: OOzSOh .. section: Library

Fix double free and null pointer dereference in unusual error scenarios in :mod:hashlib and :mod:hmac modules.

.. date: 2026-02-28-00-55-00 .. gh-issue: 145301 .. nonce: Lk2bRl .. section: Library

:mod:hmac: fix a crash when the initialization of the underlying C extension module fails.

.. date: 2026-02-27-19-00-26 .. gh-issue: 145301 .. nonce: 2Wih4b .. section: Library

:mod:hashlib: fix a crash when the initialization of the underlying C extension module fails.

.. date: 2026-02-27-18-04-51 .. gh-issue: 76007 .. nonce: 17idfK .. section: Library

The version attribute of the :mod:tarfile module is deprecated and slated for removal in Python 3.20.

.. date: 2026-02-23-20-52-55 .. gh-issue: 145158 .. nonce: vWJtxI .. section: Library

Avoid undefined behaviour from signed integer overflow when parsing format strings in the :mod:struct module.

.. date: 2026-02-21-17-34-53 .. gh-issue: 123853 .. nonce: 6RUwWh .. section: Library

Removed Windows 95 compatibility for :func:locale.getdefaultlocale.

.. date: 2026-02-20-13-03-10 .. gh-issue: 66802 .. nonce: OYcAi_ .. section: Library

Add :func:unicodedata.block function to return the Unicode block <https://www.unicode.org/versions/Unicode17.0.0/core-spec/chapter-3/#G64189>_ of a character.

.. date: 2026-02-19-20-54-25 .. gh-issue: 145033 .. nonce: X9EBPQ .. section: Library

Add :data:typing.TypeForm, implementing :pep:747. Patch by Jelle Zijlstra.

.. date: 2026-02-19-18-02-54 .. gh-issue: 141510 .. nonce: qzvYsO .. section: Library

:func:dataclasses.field: if metadata is None, use an empty :class:frozendict, instead of a :func:~types.MappingProxyType of an empty :class:dict. Patch by Victor Stinner.

.. date: 2026-02-19-17-50-47 .. gh-issue: 145006 .. nonce: 9gqA0Q .. section: Library

Add :exc:ModuleNotFoundError hints when a module for a different ABI exists.

.. date: 2026-02-19-16-26-08 .. gh-issue: 141510 .. nonce: 4Qxy8_ .. section: Library

ParameterizedMIMEHeader.params of :mod:email.headerregistry is now a :class:frozendict instead of a :class:types.MappingProxyType. Patch by Victor Stinner.

.. date: 2026-02-19-15-42-06 .. gh-issue: 134872 .. nonce: sjYX1- .. section: Library

Add valid import name suggestions on :exc:ModuleNotFoundError.

.. date: 2026-02-19-10-57-40 .. gh-issue: 88091 .. nonce: N7qGV- .. section: Library

Fix :func:unicodedata.decomposition for Hangul characters.

.. date: 2026-02-19-00-00-00 .. gh-issue: 144986 .. nonce: atexit-leak .. section: Library

Fix a memory leak in :func:atexit.register. Patch by Shamil Abdulaev.

.. date: 2026-02-18-13-45-00 .. gh-issue: 144777 .. nonce: R97q0a .. section: Library

Fix data races in :class:io.IncrementalNewlineDecoder in the :term:free-threaded build.

.. date: 2026-02-18-00-00-00 .. gh-issue: 144809 .. nonce: nYpEUx .. section: Library

Make :class:collections.deque copy atomic in the :term:free-threaded build.

.. date: 2026-02-17-11-28-37 .. gh-issue: 141510 .. nonce: OpAz0M .. section: Library

The :mod:copy module now supports the :class:frozendict type. Patch by Pieter Eendebak based on work by Victor Stinner.

.. date: 2026-02-17-11-15-17 .. gh-issue: 141510 .. nonce: ZmqEUb .. section: Library

The :mod:json module now supports the :class:frozendict type. Patch by Victor Stinner.

.. date: 2026-02-15-12-02-20 .. gh-issue: 144835 .. nonce: w_oS_J .. section: Library

Added missing explanations for some parameters in :func:glob.glob and :func:glob.iglob.

.. date: 2026-02-15-00-00-00 .. gh-issue: 144833 .. nonce: TUelo1 .. section: Library

Fixed a use-after-free in :mod:ssl when SSL_new() returns NULL in newPySSLSocket(). The error was reported via a dangling pointer after the object had already been freed.

.. date: 2026-02-14-14-56-44 .. gh-issue: 140715 .. nonce: AbSheM .. section: Library

Add '%D' support to :meth:~datetime.datetime.strptime.

.. date: 2026-02-13-14-20-10 .. gh-issue: 144782 .. nonce: 0Y8TKj .. section: Library

Fix :class:argparse.ArgumentParser to be :mod:pickleable <pickle>.

.. date: 2026-02-13-11-14-18 .. gh-issue: 144763 .. nonce: cDwnEE .. section: Library

Fix a race condition in :mod:tracemalloc: it no longer detaches the attached thread state to acquire its internal lock. Patch by Victor Stinner.

.. date: 2026-02-13-00-00-00 .. gh-issue: 142224 .. nonce: BidiMissing .. section: Library

:func:unicodedata.bidirectional now return the correct default bidi class for unassigned code points.

.. date: 2026-02-12-17-56-17 .. gh-issue: 117865 .. nonce: jE1ema .. section: Library

Reduce the import time of :mod:inspect module by ~20%.

.. date: 2026-02-10-22-05-51 .. gh-issue: 144156 .. nonce: UbrC7F .. section: Library

Fix the folding of headers by the :mod:email library when :rfc:2047 encoded words are used. Now whitespace is correctly preserved and also correctly added between adjacent encoded words. The latter property was broken by the fix for gh-92081, which mostly fixed previous failures to preserve whitespace.

.. date: 2026-02-10-16-56-05 .. gh-issue: 66305 .. nonce: PZ6GN8 .. section: Library

Fixed a hang on Windows in the :mod:tempfile module when trying to create a temporary file or subdirectory in a non-writable directory.

.. date: 2026-02-09-02-16-36 .. gh-issue: 144615 .. nonce: s04x4n .. section: Library

Methods directly decorated with :deco:functools.singledispatchmethod now dispatch on the second argument when called after being accessed as class attributes. Patch by Bartosz Sławecki.

.. date: 2026-02-08-17-09-10 .. gh-issue: 144321 .. nonce: w58PhQ .. section: Library

The functional syntax for creating :class:typing.NamedTuple classes now supports passing any :term:iterable of fields and types. Previously, only sequences were supported.

.. date: 2026-02-07-16-37-42 .. gh-issue: 144475 .. nonce: 8tFEXw .. section: Library

Calling :func:repr on :func:functools.partial is now safer when the partial object's internal attributes are replaced while the string representation is being generated.

.. date: 2026-02-07-16-31-42 .. gh-issue: 144285 .. nonce: iyH9iL .. section: Library

Attribute suggestions in :exc:AttributeError tracebacks are now formatted differently to make them easier to understand, for example: Did you mean '.datetime.now' instead of '.now'. Contributed by Bartosz Sławecki.

.. date: 2026-02-03-19-57-41 .. gh-issue: 144316 .. nonce: wop870 .. section: Library

Fix crash in _remote_debugging that caused test_external_inspection to intermittently fail. Patch by Taegyun Kim.

.. date: 2026-01-17-08-44-25 .. gh-issue: 143637 .. nonce: qyPqDo .. section: Library

Fixed a crash in socket.sendmsg() that could occur if ancillary data is mutated re-entrantly during argument parsing.

.. date: 2026-01-12-19-39-57 .. gh-issue: 140652 .. nonce: HvM9Bl .. section: Library

Fix a crash in :func:!_interpchannels.list_all after closing a channel.

.. date: 2026-01-11-18-35-52 .. gh-issue: 143698 .. nonce: gXDzsJ .. section: Library

Allow scheduler and setpgroup arguments to be explicitly :const:None when calling :func:os.posix_spawn or :func:os.posix_spawnp. Patch by Bénédikt Tran.

.. date: 2026-01-11-16-59-22 .. gh-issue: 143698 .. nonce: b-Cpeb .. section: Library

Raise :exc:TypeError instead of :exc:SystemError when the scheduler in :func:os.posix_spawn or :func:os.posix_spawnp is not a tuple. Patch by Bénédikt Tran.

.. date: 2026-01-11-13-03-32 .. gh-issue: 142516 .. nonce: u7An-s .. section: Library

:mod:ssl: fix reference leaks in :class:ssl.SSLContext objects. Patch by Bénédikt Tran.

.. date: 2026-01-10-22-58-30 .. gh-issue: 85809 .. nonce: 0eW4wt .. section: Library

Added :term:path-like object support for :func:shutil.make_archive.

.. date: 2026-01-01-05-26-00 .. gh-issue: 143304 .. nonce: Kv7x9Q .. section: Library

Fix :class:ctypes.CDLL to honor the handle parameter on POSIX systems.

.. date: 2025-12-18-00-14-16 .. gh-issue: 142781 .. nonce: gcOeYF .. section: Library

:mod:zoneinfo: fix a crash when instantiating :class:~zoneinfo.ZoneInfo objects for which the internal class-level cache is inconsistent.

.. date: 2025-12-16-13-34-48 .. gh-issue: 142787 .. nonce: wNitJX .. section: Library

Fix assertion failure in :mod:sqlite3 blob subscript when slicing with indices that result in an empty slice.

.. date: 2025-12-06-16-14-18 .. gh-issue: 142352 .. nonce: pW5HLX88 .. section: Library

Fix :meth:asyncio.StreamWriter.start_tls to transfer buffered data from :class:~asyncio.StreamReader to the SSL layer, preventing data loss when upgrading a connection to TLS mid-stream (e.g., when implementing PROXY protocol support).

.. date: 2025-10-10-14-08-58 .. gh-issue: 139899 .. nonce: 09leRY .. section: Library

Introduced :meth:importlib.abc.MetaPathFinder.discover and :meth:importlib.abc.PathEntryFinder.discover to allow module and submodule name discovery without assuming the use of traditional filesystem based imports.

.. date: 2025-08-04-23-20-43 .. gh-issue: 137335 .. nonce: IIjDJN .. section: Library

Get rid of any possibility of a name conflict for named pipes in :mod:multiprocessing and :mod:asyncio on Windows, no matter how small.

.. date: 2025-06-24-19-07-18 .. gh-issue: 135883 .. nonce: 38cePA .. section: Library

Fix :mod:sqlite3's :ref:interactive shell <sqlite3-cli> keeping part of previous commands when scrolling history.

.. date: 2024-09-30-15-31-59 .. gh-issue: 124748 .. nonce: KYzYFp .. section: Library

Improve :exc:TypeError error message when :meth:!weakref.WeakKeyDictionary.update is used with keyword-only parameters.

.. date: 2023-02-05-20-02-30 .. gh-issue: 80667 .. nonce: 7LmzeA .. section: Library

Add support for Tangut Ideographs names in :mod:unicodedata.

.. bpo: 42353 .. date: 2022-02-05-00-15-03 .. nonce: 0ebVGG .. section: Library

The :mod:re module gains a new :func:re.prefixmatch function as an explicit spelling of what has to date always been known as :func:re.match. :class:re.Pattern similary gains a :meth:re.Pattern.prefixmatch method.

Why? Explicit is better than implicit. Other widely used languages all use the term "match" to mean what Python uses the term "search" for. The unadorened "match" name in Python has been a frequent case of confusion and coding bugs due to the inconsistency with the rest if the software industry.

We do not plan to deprecate and remove the older match name.

.. bpo: 40243 .. date: 2020-04-10-14-29-53 .. nonce: 85HRib .. section: Library

Fix :meth:!unicodedata.ucd_3_2_0.numeric for non-decimal values.

.. bpo: 40212 .. date: 2020-04-07-05-09-34 .. nonce: oPYeBs .. section: Library

Re-enable :func:os.posix_fallocate and :func:os.posix_fadvise on AIX.

.. bpo: 3405 .. date: 2018-05-11-12-26-16 .. nonce: CacMw9 .. section: Library

Add support for user data of Tk virtual events and detail for Enter, Leave, FocusIn, FocusOut, and ConfigureRequest events to :mod:tkinter.

.. bpo: 32234 .. date: 2017-12-15-09-32-57 .. nonce: XaOkhR .. section: Library

:class:mailbox.Mailbox instances can now be used as a context manager. The Mailbox is locked on context entry and unlocked and closed at context exit.

.. date: 2026-03-03-08-18-00 .. gh-issue: 145450 .. nonce: VI7GXj .. section: Documentation

Document missing public :class:wave.Wave_write getter methods.

.. date: 2026-01-06-16-04-08 .. gh-issue: 110937 .. nonce: SyO5lk .. section: Documentation

Document rest of full public :class:importlib.metadata.Distribution API. Also add the (already documented) :class:~importlib.metadata.PackagePath to __all__.

.. date: 2025-08-02-18-59-01 .. gh-issue: 136246 .. nonce: RIK7nE .. section: Documentation

A new "Improve this page" link is available in the left-hand sidebar of the docs, offering links to create GitHub issues, discussion forum posts, or pull requests.

.. date: 2026-03-09-18-52-03 .. gh-issue: 145701 .. nonce: 79KQyO .. section: Core and Builtins

Fix :exc:SystemError when __classdict__ or __conditional_annotations__ is in a class-scope inlined comprehension. Found by OSS Fuzz in :oss-fuzz:491105000.

.. date: 2026-03-06-21-05-05 .. gh-issue: 145615 .. nonce: NKXXZgDW .. section: Core and Builtins

Fixed a memory leak in the :term:free-threaded build where mimalloc pages could become permanently unreclaimable until the owning thread exited.

.. date: 2026-03-06-01-36-20 .. gh-issue: 116738 .. nonce: OWVWRx .. section: Core and Builtins

Make :meth:!mmap.mmap.set_name thread-safe on the :term:free threaded <free threading> build.

.. date: 2026-03-05-19-10-56 .. gh-issue: 145566 .. nonce: H4RupyYN .. section: Core and Builtins

In the free threading build, skip the stop-the-world pause when reassigning __class__ on a newly created object.

.. date: 2026-03-05-16-16-17 .. gh-issue: 143055 .. nonce: qDUFlY .. section: Core and Builtins

Fix crash in AST unparser when unparsing dict comprehension unpacking. Found by OSS Fuzz in :oss-fuzz:489790200.

.. date: 2026-03-01-13-37-31 .. gh-issue: 145335 .. nonce: e36kPJ .. section: Core and Builtins

Fix a crash in :func:os.pathconf when called with -1 as the path argument.

.. date: 2026-02-28-16-46-17 .. gh-issue: 145376 .. nonce: lG5u1a .. section: Core and Builtins

Fix reference leaks in various unusual error scenarios.

.. date: 2026-02-26-21-36-00 .. gh-issue: 145234 .. nonce: w0mQ9n .. section: Core and Builtins

Fixed a SystemError in the parser when an encoding cookie (for example, UTF-7) decodes to carriage returns (\r). Newlines are now normalized after decoding in the string tokenizer.

Patch by Pablo Galindo.

.. date: 2026-02-26-21-07-38 .. gh-issue: 145275 .. nonce: qE-3O1 .. section: Core and Builtins

Added the :option:-X pathconfig_warnings<-X> and :envvar:PYTHON_PATHCONFIG_WARNINGS options, allowing to disable warnings from :ref:sys-path-init.

.. date: 2026-02-26-20-51-54 .. gh-issue: 145273 .. nonce: B5QcUp .. section: Core and Builtins

A warning is now shown during :ref:sys-path-init if it can't find a valid standard library.

.. date: 2026-02-26-18-00-00 .. gh-issue: 145241 .. nonce: hL2k9Q .. section: Core and Builtins

Specialized the parser error for when with items are followed by a trailing comma (for example, with item,:), raising a clearer :exc:SyntaxError message. Patch by Pablo Galindo and Bartosz Sławecki.

.. date: 2026-02-26-12-00-00 .. gh-issue: 130555 .. nonce: TMSOIu .. section: Core and Builtins

Fix use-after-free in :meth:dict.clear when the dictionary values are embedded in an object and a destructor causes re-entrant mutation of the dictionary.

.. date: 2026-02-25-15-02-08 .. gh-issue: 145197 .. nonce: G6hAUk .. section: Core and Builtins

Fix JIT trace crash when recording function from cleared generator frame.

.. date: 2026-02-24-18-30-56 .. gh-issue: 145187 .. nonce: YjPu1Z .. section: Core and Builtins

Fix compiler assertion fail when a type parameter bound contains an invalid expression in a conditional block.

.. date: 2026-02-23-23-18-28 .. gh-issue: 145142 .. nonce: T-XbVe .. section: Core and Builtins

Fix a crash in the free-threaded build when the dictionary argument to :meth:str.maketrans is concurrently modified.

.. date: 2026-02-22-22-05-09 .. gh-issue: 145118 .. nonce: TaKMJE .. section: Core and Builtins

:meth:str.maketrans now accepts :class:frozendict.

.. date: 2026-02-22-20-15-00 .. gh-issue: 144015 .. nonce: pystrhex_simd .. section: Core and Builtins

Speed up :meth:bytes.hex, :meth:bytearray.hex, :func:binascii.hexlify, and :mod:hashlib .hexdigest() operations with SIMD on x86-64, ARM64, and ARM32 with NEON when built with gcc (version 12 or higher) or clang (version 3 or higher) compilers. Around 1.1-3x faster for common 16-64 byte inputs such as hashlib hex digests, and up to 8x faster for larger data.

.. date: 2026-02-22-19-05-03 .. gh-issue: 145118 .. nonce: bU6Sic .. section: Core and Builtins

:func:type now accepts :class:frozendict as an argument.

.. date: 2026-02-22-07-51-10 .. gh-issue: 145064 .. nonce: iIMGKA .. section: Core and Builtins

Fix JIT optimizer assertion failure during CALL_ALLOC_AND_ENTER_INIT side exit.

.. date: 2026-02-21-12-16-46 .. gh-issue: 145055 .. nonce: VyT-zI .. section: Core and Builtins

:func:exec and :func:eval now accept :class:frozendict for globals. Patch by Victor Stinner.

.. date: 2026-02-21-09-47-45 .. gh-issue: 145058 .. nonce: e-RBw- .. section: Core and Builtins

Fix a crash when :func:!__lazy_import__ is passed a non-string argument, by raising an :exc:TypeError instead.

.. date: 2026-02-19-12-49-15 .. gh-issue: 144995 .. nonce: Ob2oYJ .. section: Core and Builtins

Optimize :class:memoryview comparison: a :class:memoryview is equal to itself, there is no need to compare values. Patch by Victor Stinner.

.. date: 2026-02-18-21-44-39 .. gh-issue: 141510 .. nonce: 7LST2O .. section: Core and Builtins

Update specializer to support frozendict. Patch by Donghee Na.

.. date: 2026-02-17-22-27-11 .. gh-issue: 141510 .. nonce: -4yYsf .. section: Core and Builtins

Optimize :meth:!frozendict.fromkeys to avoid unnecessary thread-safety operations in frozendict cases. Patch by Donghee Na.

.. date: 2026-02-17-21-04-03 .. gh-issue: 100239 .. nonce: LyVabQ .. section: Core and Builtins

Speedup BINARY_OP_EXTEND for exact floats and medium-size integers by up to 15%. Patch by Chris Eibl.

.. date: 2026-02-17-18-27-28 .. gh-issue: 144914 .. nonce: DcXO4m .. section: Core and Builtins

Use mimalloc for raw memory allocations such as via :c:func:PyMem_RawMalloc for better performance on :term:free-threaded builds <free-threaded build>. Patch by Kumar Aditya.

.. date: 2026-02-16-12-28-43 .. gh-issue: 144872 .. nonce: k9_Q30 .. section: Core and Builtins

Fix heap buffer overflow in the parser found by OSS-Fuzz.

.. date: 2026-02-13-18-30-59 .. gh-issue: 144766 .. nonce: JGu3x3 .. section: Core and Builtins

Fix a crash in fork child process when perf support is enabled.

.. date: 2026-02-13-12-00-00 .. gh-issue: 144759 .. nonce: d3qYpe .. section: Core and Builtins

Fix undefined behavior in the lexer when start and multi_line_start pointers are NULL in _PyLexer_remember_fstring_buffers() and _PyLexer_restore_fstring_buffers(). The NULL pointer arithmetic (NULL - valid_pointer) is now guarded with explicit NULL checks.

.. date: 2026-02-12-19-01-13 .. gh-issue: 141510 .. nonce: KlKjZg .. section: Core and Builtins

Add built-in :class:frozendict type. Patch by Victor Stinner.

.. date: 2026-02-12-12-39-50 .. gh-issue: 144681 .. nonce: Ns2OT2 .. section: Core and Builtins

Fix a JIT assertion failure when a conditional branch jumps to the same target as the fallthrough path.

.. date: 2026-02-11-13-30-11 .. gh-issue: 143300 .. nonce: yjB63- .. section: Core and Builtins

Add :c:func:PyUnstable_SetImmortal C-API function to mark objects as :term:immortal.

.. date: 2026-02-11-11-28-25 .. gh-issue: 144702 .. nonce: XjFumv .. section: Core and Builtins

Clarify the error message raised when a class pattern is used to match on a non-class object.

.. date: 2026-02-08-13-14-00 .. gh-issue: 144569 .. nonce: pjlJVe .. section: Core and Builtins

Optimize BINARY_SLICE for list, tuple, and unicode by avoiding temporary slice object creation.

.. date: 2026-02-06-21-45-52 .. gh-issue: 144438 .. nonce: GI_uB1LR .. section: Core and Builtins

Align the QSBR thread state array to a 64-byte cache line boundary to avoid false sharing in the :term:free-threaded build.

.. date: 2025-12-06-15-46-32 .. gh-issue: 142349 .. nonce: IdTuYL .. section: Core and Builtins

Implement :pep:810. Patch by Pablo Galindo and Dino Viehland.

.. date: 2025-11-09-15-44-58 .. gh-issue: 141226 .. nonce: KTb_3F .. section: Core and Builtins

Deprecate :pep:456 support for providing an external definition of the string hashing scheme. Removal is scheduled for Python 3.19. Patch by Bénédikt Tran.

.. date: 2025-09-15-13-28-48 .. gh-issue: 138912 .. nonce: 61EYbn .. section: Core and Builtins

Improve :opcode:MATCH_CLASS performance by up to 52% in certain cases. Patch by Marc Mueller.

.. date: 2025-02-19-21-06-30 .. gh-issue: 130327 .. nonce: z3TaR8 .. section: Core and Builtins

Fix erroneous clearing of an object's :attr:~object.__dict__ if overwritten at runtime.

.. date: 2023-07-26-00-03-00 .. gh-issue: 80667 .. nonce: N7Dh8B .. section: Core and Builtins

Literals using the \N{name} escape syntax can now construct CJK ideographs and Hangul syllables using case-insensitive names.

.. date: 2026-03-03-14-59-57 .. gh-issue: 142417 .. nonce: HiNP5j .. section: C API

Restore private provisional _Py_InitializeMain() function removed in Python 3.14. Patch by Victor Stinner.

.. date: 2026-02-24-14-46-05 .. gh-issue: 144748 .. nonce: uhnFtE .. section: C API

:c:func:PyErr_CheckSignals now raises the exception scheduled by :c:func:PyThreadState_SetAsyncExc, if any.

.. date: 2026-02-18-15-12-34 .. gh-issue: 144981 .. nonce: 4ZdM63 .. section: C API

Made :c:func:PyUnstable_Code_SetExtra, :c:func:PyUnstable_Code_GetExtra, and :c:func:PyUnstable_Eval_RequestCodeExtraIndex thread-safe on the :term:free threaded <free threading> build.

.. date: 2026-02-12-19-03-31 .. gh-issue: 141510 .. nonce: U_1tjz .. section: C API

Add the following functions for the new :class:frozendict type:

:c:func:PyAnyDict_Check
:c:func:PyAnyDict_CheckExact
:c:func:PyFrozenDict_Check
:c:func:PyFrozenDict_CheckExact
:c:func:PyFrozenDict_New

Patch by Victor Stinner.

.. date: 2026-02-10-14-49-49 .. gh-issue: 121617 .. nonce: 57vMqa .. section: C API

Python.h now also includes <string.h> in the limited C API version 3.11 and newer to fix the :c:macro:Py_CLEAR macro which uses memcpy(). Patch by Victor Stinner.

.. date: 2026-01-27-18-15-15 .. gh-issue: 144175 .. nonce: qHK5Jf .. section: C API

Add :c:func:PyArg_ParseArray and :c:func:PyArg_ParseArrayAndKeywords functions to parse arguments of functions using the :c:macro:METH_FASTCALL calling convention. Patch by Victor Stinner.

.. date: 2026-02-27-18-10-02 .. gh-issue: 144533 .. nonce: 21fk9L .. section: Build

Use wasmtime's --argv0 to auto-discover sysconfig in WASI builds

.. date: 2026-02-22-13-35-20 .. gh-issue: 145110 .. nonce: KgWofW .. section: Build

Fix targets "Clean" and "CLeanAll" in case of PGO builds on Windows. Patch by Chris Eibl.

.. date: 2026-02-10-18-26-04 .. gh-issue: 144679 .. nonce: FIH73W .. section: Build

When building with Visual Studio 2026 (Version 18), use PlatformToolSet v145 by default. Patch by Chris Eibl.

.. date: 2026-02-10-16-59-56 .. gh-issue: 144675 .. nonce: Wrf3Es .. section: Build

Update to WASI SDK 30.

.. date: 2025-07-21-00-33-38 .. gh-issue: 136677 .. nonce: Y1_3ec .. section: Build

Introduce executable specific linker flags to ./configure.