Python 3.12.4 released

I'm pleased to announce the release of Python 3.12.4:

https://www.python.org/downloads/release/python-3124/

 

This is the third maintenance release of Python 3.12

Python 3.12 is the newest major release of the Python programming language, and it contains many new features and optimizations. 3.12.4 is the latest maintenance release, containing more than 250 bugfixes, build improvements and documentation changes since 3.12.3.

 

Major new features of the 3.12 series, compared to 3.11

 

New features

• More flexible f-string parsing, allowing many things previously disallowed (PEP 701).
• Support for the buffer protocol in Python code (PEP 688).
• A new debugging/profiling API (PEP 669).
• Support for isolated subinterpreters with separate Global Interpreter Locks (PEP 684).
• Even more improved error messages. More exceptions potentially caused by typos now make suggestions to the user.
• Support for the Linux perf profiler to report Python function names in traces.
• Many large and small performance improvements (like PEP 709 and support for the BOLT binary optimizer), delivering an estimated 5% overall performance improvement.

Type annotations

• New type annotation syntax for generic classes (PEP 695).
• New override decorator for methods (PEP 698).

Deprecations

• The deprecated wstr and wstr_length members of the C implementation of unicode objects were removed, per PEP 623.
• In the unittest module, a number of long deprecated methods and classes were removed. (They had been deprecated since Python 3.1 or 3.2).
• The deprecated smtpd and distutils modules have been removed (see PEP 594 and PEP 632. The setuptools package continues to provide the distutils module.
• A number of other old, broken and deprecated functions, classes and methods have been removed.
• Invalid backslash escape sequences in strings now warn with SyntaxWarning instead of DeprecationWarning, making them more visible. (They will become syntax errors in the future.)
• The internal representation of integers has changed in preparation for performance enhancements. (This should not affect most users as it is an internal detail, but it may cause problems for Cython-generated code.)

For more details on the changes to Python 3.12, see What’s new in Python 3.12.

 

More resources

• Online Documentation.
• PEP 693, the Python 3.12 Release Schedule.
• Report bugs via GitHub Issues.
• Help fund Python directly or via GitHub Sponsors, and support the Python community.

 

Enjoy the new releases

Thanks to all of the many volunteers who help make Python Development and these releases possible! Please consider supporting our efforts by volunteering yourself or through organization contributions to the Python Software Foundation.

Your release team,
Thomas Wouters
Łukasz Langa
Ned Deily
Steve Dower 

Python 3.13.0 beta 2 released

I'm pleased to announce the release of Python 3.13 beta 2.

https://www.python.org/downloads/release/python-3130b2/

 

This is a beta preview of Python 3.13

Python 3.13 is still in development. This release, 3.13.0b2, is the second of four beta release previews of 3.13.

Beta release previews are intended to give the wider community the opportunity to test new features and bug fixes and to prepare their projects to support the new feature release.

We strongly encourage maintainers of third-party Python projects to test with 3.13 during the beta phase and report issues found to the Python bug tracker as soon as possible. While the release is planned to be feature complete entering the beta phase, it is possible that features may be modified or, in rare cases, deleted up until the start of the release candidate phase (Tuesday 2024-07-30). Our goal is to have no ABI changes after beta 4 and as few code changes as possible after 3.13.0rc1, the first release candidate. To achieve that, it will be extremely important to get as much exposure for 3.13 as possible during the beta phase.

Two particularly noteworthy changes in beta 2 involve the macOS installer we provide:

• The minimum supported macOS version was changed from 10.9 to 10.13 (High Sierra). Older macOS versions will not be supported going forward.
• The macOS installer package now includes an optional additional build of Python 3.13 with the experimental free-threading feature enabled. The free-threaded version, python3.13t, is separate from and co-exists with the traditional GIL-only installation. The free-threaded build is not installed by default; use the Customize option of the installer as explained in the installer readme. Since this is an experimental feature, there may be late-breaking issues found; see the free-threaded macOS build issue on GitHub for the most recent status.

Please keep in mind that this is a preview release and its use is not recommended for production environments.

 

Major new features of the 3.13 series, compared to 3.12

Some of the new major new features and changes in Python 3.13 are:

New features

• A new and improved interactive interpreter , based on PyPy’s, featuring multi-line editing and color support, as well as colorized exception tracebacks .
• An experimental free-threaded build mode , which disables the Global Interpreter Lock, allowing threads to run more concurrently.
• A preliminary, experimental JIT , providing the ground work for significant performance improvements.
• The (cyclic) garbage collector is now incremental , which should mean shorter pauses for collection in programs with a lot of objects.
• A modified version of mimalloc is now included, optional but enabled by default if supported by the platform, and required for the free-threaded build mode.
• Docstrings now have their leading indentation stripped, reducing memory use and the size of .pyc files. (Most tools handling docstrings already strip leading indentation.)
• The dbm module has a new dbm.sqlite3 backend that is used by default when creating new files.

Typing

• Support for type defaults in type parameters.
• A new type narrowing annotation , typing.TypeIs.
• A new annotation for read-only items in TypeDicts .

Removals and new deprecations

• PEP 594 (Removing dead batteries from the standard library) scheduled removals of many deprecated modules: aifc, audioop, chunk, cgi, cgitb, crypt, imghdr, mailcap, msilib, nis, nntplib, ossaudiodev, pipes, sndhdr, spwd, sunau, telnetlib, uu, xdrlib, lib2to3.
• Many other removals of deprecated classes, functions and methods in various standard library modules.
• C API removals and deprecations. (Some removals present in alpha 1 were reverted in alpha 2, as the removals were deemed too disruptive at this time.)
• New deprecations, most of which are scheduled for removal from Python 3.15 or 3.16.

(Hey, fellow core developer, if a feature you find important is missing from this list, let Thomas know.)

For more details on the changes to Python 3.13, see What’s new in Python 3.13 . The next pre-release of Python 3.13 will be 3.13.0b3, currently scheduled for 2024-06-25.

 

More resources

• Online Documentation
• PEP 719 , 3.13 Release Schedule
• Report bugs at Issues · python/cpython · GitHub .
• Help fund Python directly (or via GitHub Sponsors), and support the Python community.

 

Enjoy the new releases

Thanks to all of the many volunteers who help make Python Development and these releases possible! Please consider supporting our efforts by volunteering yourself or through organization contributions to the Python Software Foundation.

Your release team,
Thomas Wouters
Łukasz Langa
Ned Deily
Steve Dower