Here comes the antepenultimate alpha.

https://www.python.org/downloads/release/python-3140a5/

This is an early developer preview of Python 3.14

Major new features of the 3.14 series, compared to 3.13

Python 3.14 is still in development. This release, 3.14.0a5, is the fifth of seven planned alpha releases.

Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process.

During the alpha phase, features may be added up until the start of the beta phase (2025-05-06) and, if necessary, may be modified or deleted up until the release candidate phase (2025-07-22). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.14 are still being planned and written. Among the new major new features and changes so far:

• PEP 649: deferred evaluation of annotations
• PEP 741: Python configuration C API
• PEP 761: Python 3.14 and onwards no longer provides PGP signatures for release artifacts. Instead, Sigstore is recommended for verifiers.
• Improved error messages
• A new type of interpreter. For certain newer compilers, this interpreter provides significantly better performance. Opt-in for now, requires building from source.
• Python removals and deprecations
• C API removals and deprecations
• (Hey, fellow core developer, if a feature you find important is missing from this list, let Hugo know.)

The next pre-release of Python 3.14 will be the penultimate alpha, 3.14.0a6, currently scheduled for 2025-03-14.

More resources

• Online documentation
• PEP 745, 3.14 Release Schedule
• Report bugs at github.com/python/cpython/issues
• Help fund Python and its community

And now for something completely different

2025-01-29 marked the start of a new lunar year, the Year of the Snake 🐍 (and the Year of Python?).

For centuries, π was often approximated as 3 in China. Some time between the years 1 and 5 CE, astronomer, librarian, mathematician and politician Liu Xin (劉歆) calculated π as 3.154.

Around 130 CE, mathematician, astronomer, and geographer Zhang Heng (張衡, 78–139) compared the celestial circle with the diameter of the earth as 736:232 to get 3.1724. He also came up with a formula for the ratio between a cube and inscribed sphere as 8:5, implying the ratio of a square’s area to an inscribed circle is √8:√5. From this, he calculated π as √10 (~3.162).

Third century mathematician Liu Hui (刘徽) came up with an algorithm for calculating π iteratively: calculate the area of a polygon inscribed in a circle, then as the number of sides of the polygon is increased, the area becomes closer to that of the circle, from which you can approximate π.

This algorithm is similar to the method used by Archimedes in the 3rd century BCE and Ludolph van Ceulen in the 16th century CE (see 3.14.0a2 release notes), but Archimedes only went up to a 96-sided polygon (96-gon). Liu Hui went up to a 192-gon to approximate π as 157/50 (3.14) and later a 3072-gon for 3.14159.

Liu Hu wrote a commentary on the book The Nine Chapters on the Mathematical Art which included his π approximations.

In the fifth century, astronomer, inventor, mathematician, politician, and writer Zu Chongzhi (祖沖之, 429–500) used Liu Hui’s algorithm to inscribe a 12,288-gon to compute π between 3.1415926 and 3.1415927, correct to seven decimal places. This was more accurate than Hellenistic calculations and wouldn’t be improved upon for 900 years.

Happy Year of the Snake!

Enjoy the new release

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 organisation contributions to the Python Software Foundation.

Regards from a remarkably snowless Helsinki,

Your release team,
Hugo van Kemenade
Ned Deily
Steve Dower
Łukasz Langa

A small release day today! That is to say the releases are relatively small; the day itself was of average size, as most days are.

Hello, three dot fourteen dot zero alpha four!

https://www.python.org/downloads/release/python-3140a4/

This is an early developer preview of Python 3.14

Major new features of the 3.14 series, compared to 3.13

Python 3.14 is still in development. This release, 3.14.0a4, is the fourth of seven planned alpha releases.

Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process.

During the alpha phase, features may be added up until the start of the beta phase (2025-05-06) and, if necessary, may be modified or deleted up until the release candidate phase (2025-07-22). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.14 are still being planned and written. Among the new major new features and changes so far:

• PEP 649: deferred evaluation of annotations
• PEP 741: Python configuration C API
• PEP 761: Python 3.14 and onwards no longer provides PGP signatures for release artifacts. Instead, Sigstore is recommended for verifiers.
• Improved error messages
• Many removals of deprecated classes, functions, methods and parameters in various standard library modules.
• New deprecations, many of which are scheduled for removal from Python 3.16
• C API removals and deprecations
• (Hey, fellow core developer, if a feature you find important is missing from this list, let Hugo know.)

The next pre-release of Python 3.14 will be 3.14.0a5, currently scheduled for 2025-02-11.

More resources

• Online documentation
• PEP 745, 3.14 Release Schedule
• Report bugs at https://github.com/python/cpython/issues
• Help fund Python and its community

And now for something completely different

In Python, you can use Greek letters as constants. For example:

from math import pi as π

def circumference(radius: float) -> float:
    return 2 * π * radius

print(circumference(6378.137))  # 40075.016685578485

Enjoy the new release

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 organisation contributions to the Python Software Foundation.

Regards from a slushy, slippery Helsinki,

Your release team,
Hugo van Kemenade @hugovk
Ned Deily @nad
Steve Dower @steve.dower
Łukasz Langa @ambv

Alpha 2? But Alpha 1 only just came out!

https://www.python.org/downloads/release/python-3140a2/

This is an early developer preview of Python 3.14

Major new features of the 3.14 series, compared to 3.13

Python 3.14 is still in development. This release, 3.14.0a2 is the second of seven planned alpha releases.

Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process.

During the alpha phase, features may be added up until the start of the beta phase (2025-05-06) and, if necessary, may be modified or deleted up until the release candidate phase (2025-07-22). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.14 are still being planned and written. Among the new major new features and changes so far:

• PEP 649: deferred evaluation of annotations
• PEP 741: Python configuration C API
• PEP 761: Python 3.14 and onwards no longer provides PGP signatures for release artifacts. Instead, Sigstore is recommended for verifiers.
• Improved error messages
• (Hey, fellow core developer, if a feature you find important is missing from this list, let Hugo know.)

The next pre-release of Python 3.14 will be 3.14.0a3, currently scheduled for 2024-12-17.

More resources

• Online documentation
• PEP 745, 3.14 Release Schedule
• Report bugs at https://github.com/python/cpython/issues
• Help fund Python and its community

Enjoy the new release

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 organisation contributions to the Python Software Foundation.

Regards from a chilly Helsinki with snow on the way,

Your release team,
Hugo van Kemenade
Ned Deily
Steve Dower
Łukasz Langa

It's now time for a new alpha of a new version of Python!

https://www.python.org/downloads/release/python-3140a1/

This is an early developer preview of Python 3.14

Major new features of the 3.14 series, compared to 3.13

Python 3.14 is still in development. This release, 3.14.0a1 is the first of seven planned alpha releases.

Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process.

During the alpha phase, features may be added up until the start of the beta phase (2025-05-06) and, if necessary, may be modified or deleted up until the release candidate phase (2025-07-22). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.14 are still being planned and written. Among the new major new features and changes so far:

• PEP 649: deferred evaluation of annotations
• Improved error messages
• (Hey, fellow core developer, if a feature you find important is missing from this list, let Hugo know.)

The next pre-release of Python 3.14 will be 3.14.0a2, currently scheduled for 2024-11-19.

More resources

• Online documentation
• PEP 745, 3.14 Release Schedule
• Report bugs at https://github.com/python/cpython/issues
• Help fund Python and its community

Enjoy the new release

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.

Regards from a grey yet colourful Helsinki,

Your release team,
Hugo van Kemenade
Ned Deily
Steve Dower
Łukasz Langa

Python 3.13.0 is now available

I'm pleased to announce the release of Python 3.13 release candidate 3 (instead of the expected final release).

https://www.python.org/downloads/release/python-3130rc3/

This is the final release candidate of Python 3.13.0

This release, 3.13.0rc3, is the final release preview (no really) of 3.13. This release is expected to become the final 3.13.0 release, barring any critical bugs being discovered. The official release of 3.13.0 is now scheduled for Monday, 2024-10-07.

This extra, unplanned release candidate exists because of a couple of last minute issues, primarily a significant performance regression in specific workloads due to the incremental cyclic garbage collector (introduced in the alpha releases). We decided to roll back the garbage collector change in 3.13 (and continuing work in 3.14 to improve it), apply a number of other important bug fixes, and roll out a new release candidate.

There will be no ABI changes from this point forward in the 3.13 series (and there haven't been any since the beta releases).

Call to action

We strongly encourage maintainers of Python projects to prepare their projects for 3.13 compatibilities during this phase, and where necessary publish Python 3.13 wheels on PyPI to be ready for the final release of 3.13.0. Any binary wheels built against Python 3.13.0rc1 and later will work with future versions of Python 3.13. As always, report any issues to the Python bug tracker.

Please keep in mind that this is a preview release and while it’s as close to the final release as we can get it, its use is not recommended for production environments.

Core developers: time to work on documentation now

• Are all your changes properly documented?
• Are they mentioned in What’s New?
• Did you notice other changes you know of to have insufficient documentation?

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. The build mode is available as an experimental feature in the Windows and macOS installers as well.
• A preliminary, experimental JIT, providing the ground work for significant performance improvements.
• The locals() builtin function (and its C equivalent) now has well-defined semantics when mutating the returned mapping, which allows debuggers to operate more consistently.
• 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.
• The minimum supported macOS version was changed from 10.9 to 10.13 (High Sierra). Older macOS versions will not be supported going forward.
• WASI is now a Tier 2 supported platform. Emscripten is no longer an officially supported platform (but Pyodide continues to support Emscripten).
• iOS is now a Tier 3 supported platform
• Android is now a Tier 3 supported platform as well.

Typing

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

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 release of Python 3.13 will be the official 3.13.0 release, currently scheduled for Monday, 2024-10-07.

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