mirror of
https://github.com/python/cpython.git
synced 2025-08-04 17:08:35 +00:00
e18829a8ad
For unsigned integer formats in the PyArg_Parse* functions, accepting Python integers with value that is larger than the maximal value the corresponding C type or less than the minimal value for the corresponding signed integer type is now deprecated.
530 lines
19 KiB
ReStructuredText
530 lines
19 KiB
ReStructuredText
|
|
****************************
|
|
What's new in Python 3.15
|
|
****************************
|
|
|
|
:Editor: TBD
|
|
|
|
.. Rules for maintenance:
|
|
|
|
* Anyone can add text to this document. Do not spend very much time
|
|
on the wording of your changes, because your text will probably
|
|
get rewritten to some degree.
|
|
|
|
* The maintainer will go through Misc/NEWS periodically and add
|
|
changes; it's therefore more important to add your changes to
|
|
Misc/NEWS than to this file.
|
|
|
|
* This is not a complete list of every single change; completeness
|
|
is the purpose of Misc/NEWS. Some changes I consider too small
|
|
or esoteric to include. If such a change is added to the text,
|
|
I'll just remove it. (This is another reason you shouldn't spend
|
|
too much time on writing your addition.)
|
|
|
|
* If you want to draw your new text to the attention of the
|
|
maintainer, add 'XXX' to the beginning of the paragraph or
|
|
section.
|
|
|
|
* It's OK to just add a fragmentary note about a change. For
|
|
example: "XXX Describe the transmogrify() function added to the
|
|
socket module." The maintainer will research the change and
|
|
write the necessary text.
|
|
|
|
* You can comment out your additions if you like, but it's not
|
|
necessary (especially when a final release is some months away).
|
|
|
|
* Credit the author of a patch or bugfix. Just the name is
|
|
sufficient; the e-mail address isn't necessary.
|
|
|
|
* It's helpful to add the issue number as a comment:
|
|
|
|
XXX Describe the transmogrify() function added to the socket
|
|
module.
|
|
(Contributed by P.Y. Developer in :gh:`12345`.)
|
|
|
|
This saves the maintainer the effort of going through the VCS log
|
|
when researching a change.
|
|
|
|
This article explains the new features in Python 3.15, compared to 3.14.
|
|
|
|
For full details, see the :ref:`changelog <changelog>`.
|
|
|
|
.. note::
|
|
|
|
Prerelease users should be aware that this document is currently in draft
|
|
form. It will be updated substantially as Python 3.15 moves towards release,
|
|
so it's worth checking back even after reading earlier versions.
|
|
|
|
|
|
Summary --- release highlights
|
|
==============================
|
|
|
|
.. This section singles out the most important changes in Python 3.15.
|
|
Brevity is key.
|
|
|
|
|
|
.. PEP-sized items next.
|
|
|
|
|
|
|
|
New features
|
|
============
|
|
|
|
.. _whatsnew315-sampling-profiler:
|
|
|
|
High frequency statistical sampling profiler
|
|
--------------------------------------------
|
|
|
|
A new statistical sampling profiler has been added to the :mod:`profile` module as
|
|
:mod:`profile.sample`. This profiler enables low-overhead performance analysis of
|
|
running Python processes without requiring code modification or process restart.
|
|
|
|
Unlike deterministic profilers (:mod:`cProfile` and :mod:`profile`) that instrument
|
|
every function call, the sampling profiler periodically captures stack traces from
|
|
running processes. This approach provides virtually zero overhead while achieving
|
|
sampling rates of **up to 200,000 Hz**, making it the fastest sampling profiler
|
|
available for Python (at the time of its contribution) and ideal for debugging
|
|
performance issues in production environments.
|
|
|
|
Key features include:
|
|
|
|
* **Zero-overhead profiling**: Attach to any running Python process without
|
|
affecting its performance
|
|
* **No code modification required**: Profile existing applications without restart
|
|
* **Real-time statistics**: Monitor sampling quality during data collection
|
|
* **Multiple output formats**: Generate both detailed statistics and flamegraph data
|
|
* **Thread-aware profiling**: Option to profile all threads or just the main thread
|
|
|
|
Profile process 1234 for 10 seconds with default settings::
|
|
|
|
python -m profile.sample 1234
|
|
|
|
Profile with custom interval and duration, save to file::
|
|
|
|
python -m profile.sample -i 50 -d 30 -o profile.stats 1234
|
|
|
|
Generate collapsed stacks for flamegraph::
|
|
|
|
python -m profile.sample --collapsed 1234
|
|
|
|
Profile all threads and sort by total time::
|
|
|
|
python -m profile.sample -a --sort-tottime 1234
|
|
|
|
The profiler generates statistical estimates of where time is spent::
|
|
|
|
Real-time sampling stats: Mean: 100261.5Hz (9.97µs) Min: 86333.4Hz (11.58µs) Max: 118807.2Hz (8.42µs) Samples: 400001
|
|
Captured 498841 samples in 5.00 seconds
|
|
Sample rate: 99768.04 samples/sec
|
|
Error rate: 0.72%
|
|
Profile Stats:
|
|
nsamples sample% tottime (s) cumul% cumtime (s) filename:lineno(function)
|
|
43/418858 0.0 0.000 87.9 4.189 case.py:667(TestCase.run)
|
|
3293/418812 0.7 0.033 87.9 4.188 case.py:613(TestCase._callTestMethod)
|
|
158562/158562 33.3 1.586 33.3 1.586 test_compile.py:725(TestSpecifics.test_compiler_recursion_limit.<locals>.check_limit)
|
|
129553/129553 27.2 1.296 27.2 1.296 ast.py:46(parse)
|
|
0/128129 0.0 0.000 26.9 1.281 test_ast.py:884(AST_Tests.test_ast_recursion_limit.<locals>.check_limit)
|
|
7/67446 0.0 0.000 14.2 0.674 test_compile.py:729(TestSpecifics.test_compiler_recursion_limit)
|
|
6/60380 0.0 0.000 12.7 0.604 test_ast.py:888(AST_Tests.test_ast_recursion_limit)
|
|
3/50020 0.0 0.000 10.5 0.500 test_compile.py:727(TestSpecifics.test_compiler_recursion_limit)
|
|
1/38011 0.0 0.000 8.0 0.380 test_ast.py:886(AST_Tests.test_ast_recursion_limit)
|
|
1/25076 0.0 0.000 5.3 0.251 test_compile.py:728(TestSpecifics.test_compiler_recursion_limit)
|
|
22361/22362 4.7 0.224 4.7 0.224 test_compile.py:1368(TestSpecifics.test_big_dict_literal)
|
|
4/18008 0.0 0.000 3.8 0.180 test_ast.py:889(AST_Tests.test_ast_recursion_limit)
|
|
11/17696 0.0 0.000 3.7 0.177 subprocess.py:1038(Popen.__init__)
|
|
16968/16968 3.6 0.170 3.6 0.170 subprocess.py:1900(Popen._execute_child)
|
|
2/16941 0.0 0.000 3.6 0.169 test_compile.py:730(TestSpecifics.test_compiler_recursion_limit)
|
|
|
|
Legend:
|
|
nsamples: Direct/Cumulative samples (direct executing / on call stack)
|
|
sample%: Percentage of total samples this function was directly executing
|
|
tottime: Estimated total time spent directly in this function
|
|
cumul%: Percentage of total samples when this function was on the call stack
|
|
cumtime: Estimated cumulative time (including time in called functions)
|
|
filename:lineno(function): Function location and name
|
|
|
|
Summary of Interesting Functions:
|
|
|
|
Functions with Highest Direct/Cumulative Ratio (Hot Spots):
|
|
1.000 direct/cumulative ratio, 33.3% direct samples: test_compile.py:(TestSpecifics.test_compiler_recursion_limit.<locals>.check_limit)
|
|
1.000 direct/cumulative ratio, 27.2% direct samples: ast.py:(parse)
|
|
1.000 direct/cumulative ratio, 3.6% direct samples: subprocess.py:(Popen._execute_child)
|
|
|
|
Functions with Highest Call Frequency (Indirect Calls):
|
|
418815 indirect calls, 87.9% total stack presence: case.py:(TestCase.run)
|
|
415519 indirect calls, 87.9% total stack presence: case.py:(TestCase._callTestMethod)
|
|
159470 indirect calls, 33.5% total stack presence: test_compile.py:(TestSpecifics.test_compiler_recursion_limit)
|
|
|
|
Functions with Highest Call Magnification (Cumulative/Direct):
|
|
12267.9x call magnification, 159470 indirect calls from 13 direct: test_compile.py:(TestSpecifics.test_compiler_recursion_limit)
|
|
10581.7x call magnification, 116388 indirect calls from 11 direct: test_ast.py:(AST_Tests.test_ast_recursion_limit)
|
|
9740.9x call magnification, 418815 indirect calls from 43 direct: case.py:(TestCase.run)
|
|
|
|
The profiler automatically identifies performance bottlenecks through statistical
|
|
analysis, highlighting functions with high CPU usage and call frequency patterns.
|
|
|
|
This capability is particularly valuable for debugging performance issues in
|
|
production systems where traditional profiling approaches would be too intrusive.
|
|
|
|
(Contributed by Pablo Galindo and László Kiss Kollár in :gh:`135953`.)
|
|
|
|
|
|
Other language changes
|
|
======================
|
|
|
|
* Several error messages incorrectly using the term "argument" have been corrected.
|
|
(Contributed by Stan Ulbrych in :gh:`133382`.)
|
|
|
|
|
|
|
|
New modules
|
|
===========
|
|
|
|
* None yet.
|
|
|
|
|
|
Improved modules
|
|
================
|
|
|
|
dbm
|
|
---
|
|
|
|
* Added new :meth:`!reorganize` methods to :mod:`dbm.dumb` and :mod:`dbm.sqlite3`
|
|
which allow to recover unused free space previously occupied by deleted entries.
|
|
(Contributed by Andrea Oliveri in :gh:`134004`.)
|
|
|
|
* Add the ``'m'`` flag for :func:`dbm.gnu.open` which allows to disable
|
|
the use of :manpage:`mmap(2)`.
|
|
This may harm performance, but improve crash tolerance.
|
|
(Contributed by Serhiy Storchaka in :gh:`66234`.)
|
|
|
|
difflib
|
|
-------
|
|
|
|
* Improved the styling of HTML diff pages generated by the :class:`difflib.HtmlDiff`
|
|
class, and migrated the output to the HTML5 standard.
|
|
(Contributed by Jiahao Li in :gh:`134580`.)
|
|
|
|
|
|
math
|
|
----
|
|
|
|
* Add :func:`math.isnormal` and :func:`math.issubnormal` functions.
|
|
(Contributed by Sergey B Kirpichev in :gh:`132908`.)
|
|
|
|
* Add :func:`math.fmax`, :func:`math.fmin` and :func:`math.signbit` functions.
|
|
(Contributed by Bénédikt Tran in :gh:`135853`.)
|
|
|
|
|
|
os.path
|
|
-------
|
|
|
|
* The *strict* parameter to :func:`os.path.realpath` accepts a new value,
|
|
:data:`os.path.ALLOW_MISSING`.
|
|
If used, errors other than :exc:`FileNotFoundError` will be re-raised;
|
|
the resulting path can be missing but it will be free of symlinks.
|
|
(Contributed by Petr Viktorin for :cve:`2025-4517`.)
|
|
|
|
|
|
shelve
|
|
------
|
|
|
|
* Added new :meth:`!reorganize` method to :mod:`shelve` used to recover unused free
|
|
space previously occupied by deleted entries.
|
|
(Contributed by Andrea Oliveri in :gh:`134004`.)
|
|
|
|
|
|
sqlite3
|
|
-------
|
|
|
|
* The :ref:`command-line interface <sqlite3-cli>` has several new features:
|
|
|
|
* SQL keyword completion on <tab>.
|
|
(Contributed by Long Tan in :gh:`133393`.)
|
|
|
|
* Prompts, error messages, and help text are now colored.
|
|
This is enabled by default, see :ref:`using-on-controlling-color` for
|
|
details.
|
|
(Contributed by Stan Ulbrych and Łukasz Langa in :gh:`133461`)
|
|
|
|
|
|
ssl
|
|
---
|
|
|
|
* Indicate through :data:`ssl.HAS_PSK_TLS13` whether the :mod:`ssl` module
|
|
supports "External PSKs" in TLSv1.3, as described in RFC 9258.
|
|
(Contributed by Will Childs-Klein in :gh:`133624`.)
|
|
|
|
|
|
tarfile
|
|
-------
|
|
|
|
* :func:`~tarfile.data_filter` now normalizes symbolic link targets in order to
|
|
avoid path traversal attacks.
|
|
(Contributed by Petr Viktorin in :gh:`127987` and :cve:`2025-4138`.)
|
|
* :func:`~tarfile.TarFile.extractall` now skips fixing up directory attributes
|
|
when a directory was removed or replaced by another kind of file.
|
|
(Contributed by Petr Viktorin in :gh:`127987` and :cve:`2024-12718`.)
|
|
* :func:`~tarfile.TarFile.extract` and :func:`~tarfile.TarFile.extractall`
|
|
now (re-)apply the extraction filter when substituting a link (hard or
|
|
symbolic) with a copy of another archive member, and when fixing up
|
|
directory attributes.
|
|
The former raises a new exception, :exc:`~tarfile.LinkFallbackError`.
|
|
(Contributed by Petr Viktorin for :cve:`2025-4330` and :cve:`2024-12718`.)
|
|
* :func:`~tarfile.TarFile.extract` and :func:`~tarfile.TarFile.extractall`
|
|
no longer extract rejected members when
|
|
:func:`~tarfile.TarFile.errorlevel` is zero.
|
|
(Contributed by Matt Prodani and Petr Viktorin in :gh:`112887`
|
|
and :cve:`2025-4435`.)
|
|
|
|
|
|
zlib
|
|
----
|
|
|
|
* Allow combining two Adler-32 checksums via :func:`~zlib.adler32_combine`.
|
|
(Contributed by Callum Attryde and Bénédikt Tran in :gh:`134635`.)
|
|
|
|
* Allow combining two CRC-32 checksums via :func:`~zlib.crc32_combine`.
|
|
(Contributed by Bénédikt Tran in :gh:`134635`.)
|
|
|
|
|
|
.. Add improved modules above alphabetically, not here at the end.
|
|
|
|
Optimizations
|
|
=============
|
|
|
|
module_name
|
|
-----------
|
|
|
|
* TODO
|
|
|
|
|
|
|
|
Deprecated
|
|
==========
|
|
|
|
hashlib
|
|
-------
|
|
|
|
* In hash function constructors such as :func:`~hashlib.new` or the
|
|
direct hash-named constructors such as :func:`~hashlib.md5` and
|
|
:func:`~hashlib.sha256`, their optional initial data parameter could
|
|
also be passed a keyword argument named ``data=`` or ``string=`` in
|
|
various :mod:`hashlib` implementations.
|
|
|
|
Support for the ``string`` keyword argument name is now deprecated and
|
|
is slated for removal in Python 3.19. Prefer passing the initial data as
|
|
a positional argument for maximum backwards compatibility.
|
|
|
|
(Contributed by Bénédikt Tran in :gh:`134978`.)
|
|
|
|
|
|
.. Add deprecations above alphabetically, not here at the end.
|
|
|
|
Removed
|
|
=======
|
|
|
|
ctypes
|
|
------
|
|
|
|
* Removed the undocumented function :func:`!ctypes.SetPointerType`,
|
|
which has been deprecated since Python 3.13.
|
|
(Contributed by Bénédikt Tran in :gh:`133866`.)
|
|
|
|
|
|
http.server
|
|
-----------
|
|
|
|
* Removed the :class:`!CGIHTTPRequestHandler` class
|
|
and the ``--cgi`` flag from the :program:`python -m http.server`
|
|
command-line interface. They were deprecated in Python 3.13.
|
|
(Contributed by Bénédikt Tran in :gh:`133810`.)
|
|
|
|
|
|
platform
|
|
--------
|
|
|
|
* Removed the :func:`!platform.java_ver` function,
|
|
which was deprecated since Python 3.13.
|
|
(Contributed by Alexey Makridenko in :gh:`133604`.)
|
|
|
|
|
|
sre_*
|
|
-----
|
|
|
|
* Removed :mod:`!sre_compile`, :mod:`!sre_constants` and :mod:`!sre_parse` modules.
|
|
(Contributed by Stan Ulbrych in :gh:`135994`.)
|
|
|
|
|
|
sysconfig
|
|
---------
|
|
|
|
* Removed the *check_home* parameter of :func:`sysconfig.is_python_build`.
|
|
(Contributed by Filipe Laíns in :gh:`92897`.)
|
|
|
|
|
|
threading
|
|
---------
|
|
|
|
* Remove support for arbitrary positional or keyword arguments in the C
|
|
implementation of :class:`~threading.RLock` objects. This was deprecated
|
|
in Python 3.14.
|
|
(Contributed by Bénédikt Tran in :gh:`134087`.)
|
|
|
|
|
|
typing
|
|
------
|
|
|
|
* The undocumented keyword argument syntax for creating
|
|
:class:`~typing.NamedTuple` classes (for example,
|
|
``Point = NamedTuple("Point", x=int, y=int)``) is no longer supported.
|
|
Use the class-based syntax or the functional syntax instead.
|
|
(Contributed by Bénédikt Tran in :gh:`133817`.)
|
|
|
|
* Using ``TD = TypedDict("TD")`` or ``TD = TypedDict("TD", None)`` to
|
|
construct a :class:`~typing.TypedDict` type with zero field is no
|
|
longer supported. Use ``class TD(TypedDict): pass``
|
|
or ``TD = TypedDict("TD", {})`` instead.
|
|
(Contributed by Bénédikt Tran in :gh:`133823`.)
|
|
|
|
|
|
unittest
|
|
--------
|
|
|
|
* Lets users specify formatter in TestCase.assertLogs.
|
|
:func:`unittest.TestCase.assertLogs` will now accept a formatter
|
|
to control how messages are formatted.
|
|
(Contributed by Garry Cairns in :gh:`134567`.)
|
|
|
|
|
|
wave
|
|
----
|
|
|
|
* Removed the ``getmark()``, ``setmark()`` and ``getmarkers()`` methods
|
|
of the :class:`~wave.Wave_read` and :class:`~wave.Wave_write` classes,
|
|
which were deprecated since Python 3.13.
|
|
(Contributed by Bénédikt Tran in :gh:`133873`.)
|
|
|
|
|
|
Porting to Python 3.15
|
|
======================
|
|
|
|
This section lists previously described changes and other bugfixes
|
|
that may require changes to your code.
|
|
|
|
|
|
Build changes
|
|
=============
|
|
|
|
* Removed implicit fallback to the bundled copy of the ``libmpdec`` library.
|
|
Now this should be explicitly enabled with :option:`--with-system-libmpdec`
|
|
set to ``no`` or with :option:`!--without-system-libmpdec`.
|
|
(Contributed by Sergey B Kirpichev in :gh:`115119`.)
|
|
|
|
|
|
C API changes
|
|
=============
|
|
|
|
New features
|
|
------------
|
|
|
|
* Add :c:func:`PySys_GetAttr`, :c:func:`PySys_GetAttrString`,
|
|
:c:func:`PySys_GetOptionalAttr`, and :c:func:`PySys_GetOptionalAttrString`
|
|
functions as replacements for :c:func:`PySys_GetObject`.
|
|
(Contributed by Serhiy Storchaka in :gh:`108512`.)
|
|
|
|
* Add :c:type:`PyUnstable_Unicode_GET_CACHED_HASH` to get the cached hash of
|
|
a string. See the documentation for caveats.
|
|
(Contributed by Petr Viktorin in :gh:`131510`)
|
|
|
|
|
|
Porting to Python 3.15
|
|
----------------------
|
|
|
|
* :class:`sqlite3.Connection` APIs has been cleaned up.
|
|
|
|
* All parameters of :func:`sqlite3.connect` except *database* are now keyword-only.
|
|
* The first three parameters of methods :meth:`~sqlite3.Connection.create_function`
|
|
and :meth:`~sqlite3.Connection.create_aggregate` are now positional-only.
|
|
* The first parameter of methods :meth:`~sqlite3.Connection.set_authorizer`,
|
|
:meth:`~sqlite3.Connection.set_progress_handler` and
|
|
:meth:`~sqlite3.Connection.set_trace_callback` is now positional-only.
|
|
|
|
(Contributed by Serhiy Storchaka in :gh:`133595`.)
|
|
|
|
* Private functions promoted to public C APIs:
|
|
|
|
* ``PyMutex_IsLocked()`` : :c:func:`PyMutex_IsLocked`
|
|
|
|
The |pythoncapi_compat_project| can be used to get most of these new
|
|
functions on Python 3.14 and older.
|
|
|
|
Deprecated C APIs
|
|
-----------------
|
|
|
|
* For unsigned integer formats in :c:func:`PyArg_ParseTuple`,
|
|
accepting Python integers with value that is larger than the maximal value
|
|
for the C type or less than the minimal value for the corresponding
|
|
signed integer type of the same size is now deprecated.
|
|
(Contributed by Serhiy Storchaka in :gh:`132629`.)
|
|
|
|
.. Add C API deprecations above alphabetically, not here at the end.
|
|
|
|
Removed C APIs
|
|
--------------
|
|
|
|
* Remove deprecated ``PyUnicode`` functions:
|
|
|
|
* :c:func:`!PyUnicode_AsDecodedObject`:
|
|
Use :c:func:`PyCodec_Decode` instead.
|
|
* :c:func:`!PyUnicode_AsDecodedUnicode`:
|
|
Use :c:func:`PyCodec_Decode` instead; Note that some codecs (for example, "base64")
|
|
may return a type other than :class:`str`, such as :class:`bytes`.
|
|
* :c:func:`!PyUnicode_AsEncodedObject`:
|
|
Use :c:func:`PyCodec_Encode` instead.
|
|
* :c:func:`!PyUnicode_AsEncodedUnicode`:
|
|
Use :c:func:`PyCodec_Encode` instead; Note that some codecs (for example, "base64")
|
|
may return a type other than :class:`bytes`, such as :class:`str`.
|
|
|
|
(Contributed by Stan Ulbrych in :gh:`133612`)
|
|
|
|
* :c:func:`!PyImport_ImportModuleNoBlock`: deprecated alias
|
|
of :c:func:`PyImport_ImportModule`.
|
|
(Contributed by Bénédikt Tran in :gh:`133644`.)
|
|
|
|
The following functions are removed in favor of :c:func:`PyConfig_Get`.
|
|
The |pythoncapi_compat_project| can be used to get :c:func:`!PyConfig_Get`
|
|
on Python 3.13 and older.
|
|
|
|
* Python initialization functions:
|
|
|
|
* :c:func:`!Py_GetExecPrefix`:
|
|
use :c:func:`PyConfig_Get("base_exec_prefix") <PyConfig_Get>`
|
|
(:data:`sys.base_exec_prefix`) instead.
|
|
Use :c:func:`PyConfig_Get("exec_prefix") <PyConfig_Get>`
|
|
(:data:`sys.exec_prefix`) if :ref:`virtual environments <venv-def>`
|
|
need to be handled.
|
|
* :c:func:`!Py_GetPath`:
|
|
use :c:func:`PyConfig_Get("module_search_paths") <PyConfig_Get>`
|
|
(:data:`sys.path`) instead.
|
|
* :c:func:`!Py_GetPrefix`:
|
|
use :c:func:`PyConfig_Get("base_prefix") <PyConfig_Get>`
|
|
(:data:`sys.base_prefix`) instead.
|
|
Use :c:func:`PyConfig_Get("prefix") <PyConfig_Get>`
|
|
(:data:`sys.prefix`) if :ref:`virtual environments <venv-def>`
|
|
need to be handled.
|
|
* :c:func:`!Py_GetProgramFullPath`:
|
|
use :c:func:`PyConfig_Get("executable") <PyConfig_Get>`
|
|
(:data:`sys.executable`) instead.
|
|
* :c:func:`!Py_GetProgramName`:
|
|
use :c:func:`PyConfig_Get("executable") <PyConfig_Get>`
|
|
(:data:`sys.executable`) instead.
|
|
* :c:func:`!Py_GetPythonHome`:
|
|
use :c:func:`PyConfig_Get("home") <PyConfig_Get>` or the
|
|
:envvar:`PYTHONHOME` environment variable instead.
|
|
|
|
(Contributed by Bénédikt Tran in :gh:`133644`.)
|
|
|
|
.. |pythoncapi_compat_project| replace:: |pythoncapi_compat_project_link|_
|
|
.. |pythoncapi_compat_project_link| replace:: pythoncapi-compat project
|
|
.. _pythoncapi_compat_project_link: https://github.com/python/pythoncapi-compat
|