Allow to force color output on Windows using environment variables. Patch by Andrey Efremov.
Makes the presence of the :mod:`turtle` module dependent on the Tcl/Tk installer option. Previously, the module was always installed but would be unusable without Tcl/Tk.
Add support for multi-argument :mod:`gettext` functions in :program:`pygettext.py`.
Test the limited C API in test_cppext. Patch by Victor Stinner.
Add tests for the :mod:`dis` command-line interface. Patch by Bénédikt Tran.
iOS test results are now streamed during test execution, and the deprecated xcresulttool is no longer used.
Disable strace based system call tests when LD_PRELOAD is set.
Filter out memory-related mmap, munmap, and mprotect calls from
file-related ones when testing :mod:`io` behavior using strace.
Fixed the :class:`!asyncio.selector_events._SelectorSocketTransport` transport not pausing writes for the protocol when the buffer reaches the high water mark when using :meth:`asyncio.WriteTransport.writelines`.
Fix crash when using :mod:`atexit` concurrently on the :term:`free-threaded <free threading>` build.
Detect recursive calls in ctypes _as_parameter_ handling. Patch by
Victor Stinner.
The :mod:`platform` module now correctly detects Windows Server 2025.
Fixed :func:`sysconfig.get_config_vars`, :func:`sysconfig.get_paths`, and siblings, returning outdated cached data if the value of :data:`sys.prefix` or :data:`sys.exec_prefix` changes. Overwriting :data:`sys.prefix` or :data:`sys.exec_prefix` still is discouraged, as that might break other parts of the code.
Add colour to :mod:`test.regrtest` output. Patch by Hugo van Kemenade.
Added validation for more than one var-positional or var-keyword parameters in :class:`inspect.Signature`. Patch by Maxim Ageev.
Added posix._emscripten_debugger() to help with debugging the test suite
on the Emscripten target.
macOS and iOS apps can now choose to redirect stdout and stderr to the system log during interpreter configuration.
Include <sys/pidfd.h> to get os.PIDFD_NONBLOCK constant. Patch by
Victor Stinner.
Add the EPOLLWAKEUP constant to the :mod:`select` module.
Make :func:`operator.methodcaller` thread-safe and re-entrant safe.
:func:`pdb.set_trace` will not stop at an opcode that does not have an associated line number anymore.
Fixed bug where, on cross-builds, the :mod:`sysconfig` POSIX data was being
generated with the host Python's Makefile. The data is now generated
from current build's Makefile.
Add the :option:`dis --specialized` command-line option to show specialized bytecode. Patch by Bénédikt Tran.
Revert addition of :meth:`!pathlib.Path.scandir`. This method was added in 3.14.0a2. The optimizations remain for file system paths, but other subclasses should only have to implement :meth:`pathlib.Path.iterdir`.
In :mod:`ssl`, system call failures that OpenSSL reports using
ERR_LIB_SYS are now raised as :exc:`OSError`.
On Linux, :class:`threading.Thread` now sets the thread name to the operating system. Patch by Victor Stinner.
Publicly expose :data:`~token.EXACT_TOKEN_TYPES` in :attr:`!token.__all__`.
:mod:`ssl` can show descriptions for errors added in OpenSSL 3.4.
Fix faulthandler for trampoline frames. If the top-most frame is a trampoline frame, skip it. Patch by Victor Stinner.
A _sysconfig_vars_(...).json file is now shipped in the standard library
directory. It contains the output of :func:`sysconfig.get_config_vars` on
the default environment encoded as JSON data. This is an implementation
detail, and may change at any time.
Remove outdated socket.NETLINK_* constants not present in Linux kernels
beyond 2.6.17.
The :func:`~ctypes.CopyComPointer` function is now public. Previously, this
was private and only available in _ctypes.
Fix :meth:`!io.StringIO.__setstate__` crash, when :const:`None` was passed as the first value.
Fix :func:`urllib.request.pathname2url` for paths starting with multiple slashes on Posix.
:func:`urllib.request.pathname2url` now adds an empty authority when
generating a URL for a path that begins with exactly one slash. For example,
the path /etc/hosts is converted to the scheme-less URL
///etc/hosts. As a result of this change, URLs without authorities are
only generated for relative paths.
Add colour to :mod:`unittest` output. Patch by Hugo van Kemenade.
Fix :mod:`shutil.which` on Windows. Now it looks at direct match if and only if the command ends with a PATHEXT extension or X_OK is not in mode. Support extensionless files if "." is in PATHEXT. Support PATHEXT extensions that end with a dot.
Support PyREPL history on Windows. Patch by devdanzin and Victor Stinner.
:func:`urllib.request.pathname2url` and :func:`~urllib.request.url2pathname` no longer convert Windows drive letters to uppercase.
Fix issue where :func:`urllib.request.url2pathname` failed to discard an extra slash before a UNC drive in the URL path on Windows.
Fix issue where :func:`urllib.request.url2pathname` failed to discard any 'localhost' authority present in the URL.
Fix crash when calling a :func:`operator.methodcaller` instance from multiple threads in the free threading build.
Fix value of :attr:`urllib.response.addinfourl.url` for file: URLs that
express relative paths and absolute Windows paths. The canonical URL
generated by :func:`urllib.request.pathname2url` is now used.
Fix LONG and INT opcodes to only use base 10 for string to integer conversion in :mod:`pickle`.
Fix support of STRING and GLOBAL opcodes with non-ASCII arguments in
:mod:`pickletools`. :func:`pickletools.dis` now outputs non-ASCII bytes in
STRING, BINSTRING and SHORT_BINSTRING arguments as escaped (\xXX).
:mod:`grp`: Make :func:`grp.getgrall` thread-safe by adding a mutex. Patch by Victor Stinner.
Fix the representation of :class:`itertools.count` objects when the count value is :data:`sys.maxsize`.
The :exc:`~ctypes.COMError` exception is now public. Previously, this was
private and only available in _ctypes.
When running under a virtual environment with the :mod:`site` disabled (see :option:`-S`), :data:`sys.prefix` and :data:`sys.base_prefix` will now point to the virtual environment, instead of the base installation.
In the :mod:`trace` module, increase the coverage precision (cov%) to
one decimal.
Improve import time of :mod:`mimetypes` by around 11-16 times. Patch by Hugo van Kemenade.
Raise :exc:`TypeError` in :meth:`!_pydatetime.timedelta.__new__` if the passed arguments are not :class:`int` or :class:`float`, so that the Python implementation is in line with the C implementation.
Improve the :exc:`~getopt.GetoptError` error message when a long option prefix matches multiple accepted options in :func:`getopt.getopt` and :func:`getopt.gnu_getopt`.
Make tkinter widget methods :meth:`!after` and :meth:`!after_idle` accept arguments passed by keyword.
Fix issue where :func:`urllib.request.url2pathname` and :func:`~urllib.request.pathname2url` always used UTF-8 when quoting and unquoting file URIs. They now use the :term:`filesystem encoding and error handler`.
Fix :func:`os.path.normpath` for drive-relative paths on Windows.
Make :func:`linecache.checkcache` thread safe and GC re-entrancy safe.
Fix issue where :func:`urllib.request.pathname2url` raised :exc:`OSError` when given a Windows path containing a colon character not following a drive letter, such as before an NTFS alternate data stream.
locale.nl_langinfo(locale.ERA) now returns multiple era description
segments separated by semicolons. Previously it only returned the first
segment on platforms with Glibc.
Add :data:`~errno.EHWPOISON` error code to :mod:`errno`.
Fixed intermittent failures of :any:`os.confstr`, :any:`os.pathconf` and :any:`os.sysconf` on iOS and Android.
The usage parameter of :class:`argparse.ArgumentParser` no longer
affects the default value of the prog parameter in subparsers.
Fix possible crash (in debug build), incorrect output or returning incorrect
value from raw binary write() when writing to console on Windows.
The :mod:`http.cookies` module now supports parsing obsolete RFC 850 date formats, in accordance with RFC 9110 requirements. Patch by Nano Zheng.
:func:`readline.append_history_file` now raises a :exc:`ValueError` when given a negative value.
Guarantee that the position of a file-like object passed to :func:`zipfile.is_zipfile` is left untouched after the call. Patch by Bénédikt Tran.
Improve the performances of :func:`fnmatch.translate` by a factor 1.7. Patch by Bénédikt Tran.
Fixed :class:`multiprocessing.Process` reporting a .exitcode of 1 even
on success when using the "fork" start method while using a
:class:`concurrent.futures.ThreadPoolExecutor`.
Authentication was added to the :mod:`multiprocessing` forkserver start method control socket so that only processes with the authentication key generated by the process that spawned the forkserver can control it. This is an enhancement over the other :gh:`97514` fixes so that access is no longer limited only by filesystem permissions.
The file descriptor exchange of control pipes with the forked worker process now requires an explicit acknowledgement byte to be sent over the socket after the exchange on all forkserver supporting platforms. That makes testing the above much easier.
Publicly expose :func:`traceback.print_list` in :attr:`!traceback.__all__`.
Fix error message in :func:`bytes.fromhex` when given an odd number of digits to properly indicate that an even number of hexadecimal digits is required.
PySequence_Tuple now creates the resulting tuple atomically, preventing
partially created tuples being visible to the garbage collector or through
gc.get_referrers()
Fix statistics for increments of object reference counts (in particular, when a reference count was increased by more than 1 in a single operation).
When raising :exc:`ImportError` for missing symbols in from imports, use
__file__ in the error message if __spec__.origin is not a location
Fix non-thread-safe object resurrection when calling finalizers and watcher callbacks in the free threading build.
The iOS compiler shims can now accept arguments with spaces.
Add missing locks around some list assignment operations in the free threading build.
Fix race when exporting a buffer from a :class:`memoryview` object on the :term:`free-threaded <free threading>` build.
Correct error message for :func:`sys.set_int_max_str_digits`.
Fix possible undefined behavior division by zero in :class:`complex`'s :c:func:`_Py_c_pow`.
Calling :meth:`argparse.ArgumentParser.add_argument_group` on an argument group, and calling :meth:`argparse.ArgumentParser.add_argument_group` or :meth:`argparse.ArgumentParser.add_mutually_exclusive_group` on a mutually exclusive group now raise exceptions. This nesting was never supported, often failed to work correctly, and was unintentionally exposed through inheritance. This functionality has been deprecated since Python 3.11.
Add a marking phase to the GC. All objects that can be transitively reached from builtin modules or the stacks are marked as reachable before cycle detection. This reduces the amount of work done by the GC by approximately half.
Fix a crash in the free threading build when :c:func:`PyCode_GetCode`, :c:func:`PyCode_GetVarnames`, :c:func:`PyCode_GetCellvars`, or :c:func:`PyCode_GetFreevars` were called from multiple threads at the same time.
Simplify GC tracking of dictionaries. All dictionaries are tracked when created, rather than being lazily tracked when a trackable object was added to them. This simplifies the code considerably and results in a slight speedup.
Fix :meth:`~object.__buffer__` of :class:`bytearray` crashing when :attr:`~inspect.BufferFlags.READ` or :attr:`~inspect.BufferFlags.WRITE` are passed as flags.
Fix :exc:`TypeError` when a :class:`ctypes.Structure` has a field size that doesn't fit into an unsigned 16-bit integer. Instead, the maximum number of bits is :data:`sys.maxsize`.
Increase performance of :class:`int` by adding a freelist for compact ints.
Fix crash in finalization of dtoa state. Patch by Kumar Aditya.
Require cold or invalidated code to "warm up" before being JIT compiled again.
Ensure stack traces are complete when throwing into a generator chain that ends in a custom generator.
Optimize decoding of short UTF-8 sequences containing non-ASCII characters by approximately 15%.
Add :meth:`memoryview.index` to :class:`memoryview` objects. Patch by Bénédikt Tran.
Add :meth:`memoryview.count` to :class:`memoryview` objects. Patch by Bénédikt Tran.
Fix crash in free-threaded builds when replacing object dictionary while reading attribute on another thread
Implement mixed-mode arithmetic rules combining real and complex numbers as specified by C standards since C99. Patch by Sergey B Kirpichev.
Correct invalid corner cases which resulted in (nan+nanj) output in
complex multiplication, e.g., (1e300+1j)*(nan+infj). Patch by Sergey B
Kirpichev.
If :func:`!_thread.start_new_thread` fails to start a new thread, it deletes its state from interpreter and thus avoids its repeated cleanup on finalization.
The previously undocumented function :c:func:`PySequence_In` is :term:`soft deprecated`. Use :c:func:`PySequence_Contains` instead.
Fix loss of callbacks after more than one call to :c:func:`PyUnstable_AtExit`.
The :ref:`Unicode Exception Objects <unicodeexceptions>` C API now raises a :exc:`TypeError` if its exception argument is not a :exc:`UnicodeError` object. Patch by Bénédikt Tran.
Ensure that the value of :attr:`UnicodeEncodeError.end <UnicodeError.end>`
retrieved by :c:func:`PyUnicodeEncodeError_GetEnd` lies in [min(1,
objlen), max(min(1, objlen), objlen)] where objlen is the length of
:attr:`UnicodeEncodeError.object <UnicodeError.object>`. Similar arguments
apply to :exc:`UnicodeDecodeError` and :exc:`UnicodeTranslateError` and
their corresponding C interface. Patch by Bénédikt Tran.
Improve error message when calling the C API without an active thread state on the :term:`free-threaded <free threading>` build.
Ensure that the value of :attr:`UnicodeEncodeError.start
<UnicodeError.start>` retrieved by :c:func:`PyUnicodeEncodeError_GetStart`
lies in [0, max(0, objlen - 1)] where objlen is the length of
:attr:`UnicodeEncodeError.object <UnicodeError.object>`. Similar arguments
apply to :exc:`UnicodeDecodeError` and :exc:`UnicodeTranslateError` and
their corresponding C interface. Patch by Bénédikt Tran.
Reading text from a non-blocking stream with read may now raise a
:exc:`BlockingIOError` if the operation cannot immediately return bytes.
Add a new import and export API for Python :class:`int` objects (PEP 757):
- :c:func:`PyLong_GetNativeLayout`;
- :c:func:`PyLong_Export`;
- :c:func:`PyLong_FreeExport`;
- :c:func:`PyLongWriter_Create`;
- :c:func:`PyLongWriter_Finish`;
- :c:func:`PyLongWriter_Discard`.
Patch by Victor Stinner.
PyThreadState_Clear() now warns (and calls sys.excepthook) if the
thread state still has an active exception.
Fix build failure on systems without thread-locals support.
Emscripten builds now include ctypes support.
Updated the Emscripten web example to use ES6 modules and be built into a
distinct web_example subfolder.
Make jit_stencils.h (which is produced during JIT builds) reproducible.
The Emscripten build of Python is now based on ES6 modules.