Python 3.14 release candidate 1 is go!

It’s the first 3.14 release candidate!

https://www.python.org/downloads/release/python-3140rc1/

This is the first release candidate of Python 3.14

This release, 3.14.0rc1, is the penultimate release preview. Entering the release candidate phase, only reviewed code changes which are clear bug fixes are allowed between this release candidate and the final release. The second candidate (and the last planned release preview) is scheduled for Tuesday, 2025-08-26, while the official release of 3.14.0 is scheduled for Tuesday, 2025-10-07.

There will be no ABI changes from this point forward in the 3.14 series, and the goal is that there will be as few code changes as possible.

Call to action

We strongly encourage maintainers of third-party Python projects to prepare their projects for 3.14 during this phase, and where necessary publish Python 3.14 wheels on PyPI to be ready for the final release of 3.14.0, and to help other projects do their own testing. Any binary wheels built against Python 3.14.0rc1 will work with future versions of Python 3.14. 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 3.14 series, compared to 3.13

Some of the major new features and changes in Python 3.14 are:

New features

• PEP 779: Free-threaded Python is officially supported
• PEP 649: The evaluation of type annotations is now deferred, improving the semantics of using annotations.
• PEP 750: Template string literals (t-strings) for custom string processing, using the familiar syntax of f-strings.
• PEP 734: Multiple interpreters in the stdlib.
• PEP 784: A new module compression.zstd providing support for the Zstandard compression algorithm.
• PEP 758: except and except* expressions may now omit the brackets.
• Syntax highlighting in PyREPL, and support for color in unittest, argparse, json and calendar CLIs.
• PEP 768: A zero-overhead external debugger interface for CPython.
• UUID versions 6-8 are now supported by the uuid module, and generation of versions 3-5 are up to 40% faster.
• PEP 765: Disallow return/break/continue that exit a finally block.
• PEP 741: An improved C API for configuring Python.
• A new type of interpreter. For certain newer compilers, this interpreter provides significantly better performance. Opt-in for now, requires building from source.
• Improved error messages.
• Builtin implementation of HMAC with formally verified code from the HACL* project.
• A new command-line interface to inspect running Python processes using asynchronous tasks.
• The pdb module now supports remote attaching to a running Python process.

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

For more details on the changes to Python 3.14, see What’s new in Python 3.14. The next pre-release of Python 3.14 will be the final release candidate, 3.14.0rc2, scheduled for 2025-08-26.

Build changes

• PEP 761: Python 3.14 and onwards no longer provides PGP signatures for release artifacts. Instead, Sigstore is recommended for verifiers.
• Official macOS and Windows release binaries include an experimental JIT compiler.

Incompatible changes, removals and new deprecations

• Incompatible changes
• Python removals and deprecations
• C API removals and deprecations
• Overview of all pending deprecations

Python install manager

The installer we offer for Windows is being replaced by our new install manager, which can be installed from the Windows Store or from its download page. See our documentation for more information. The JSON file available for download below contains the list of all the installable packages available as part of this release, including file URLs and hashes, but is not required to install the latest release. The traditional installer will remain available throughout the 3.14 and 3.15 releases.

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

Today, 22nd July, is Pi Approximation Day, because 22/7 is a common approximation of π and closer to π than 3.14.

22/7 is a Diophantine approximation, named after Diophantus of Alexandria (3rd century CE), which is a way of estimating a real number as a ratio of two integers. 22/7 has been known since antiquity; Archimedes (3rd century BCE) wrote the first known proof that 22/7 overestimates π by comparing 96-sided polygons to the circle it circumscribes.

Another approximation is 355/113. In Chinese mathematics, 22/7 and 355/113 are respectively known as Yuelü (约率; yuēlǜ; “approximate ratio”) and Milü (密率; mìlǜ; “close ratio”).

Happy Pi Approximation Day!

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 Helsinki heatwave after an excellent EuroPython,

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

Python 3.14.0 beta 4 is here!

It’s the final 3.14 beta!

https://www.python.org/downloads/release/python-3140b4/

This is a beta preview of Python 3.14

Python 3.14 is still in development. This release, 3.14.0b4, is the last of four planned beta releases.

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 3.14 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 2025-07-22). Our goal is to have no ABI changes after beta 4 and as few code changes as possible after the first release candidate. To achieve that, it will be extremely important to get as much exposure for 3.14 as possible during the beta phase.

This includes creating pre-release wheels for 3.14, as it helps other projects to do their own testing. However, we recommend that your regular production releases wait until 3.14.0rc1, to avoid the risk of ABI breaks.

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

Major new features of the 3.14 series, compared to 3.13

Some of the major new features and changes in Python 3.14 are:

New features

Note that PEPs 734 and 779 are exceptionally new in beta 3!

• PEP 779: Free-threaded Python is officially supported
• PEP 649: The evaluation of type annotations is now deferred, improving the semantics of using annotations.
• PEP 750: Template string literals (t-strings) for custom string processing, using the familiar syntax of f-strings.
• PEP 734: Multiple interpreters in the stdlib.
• PEP 784: A new module compression.zstd providing support for the Zstandard compression algorithm.
• PEP 758: except and except* expressions may now omit the brackets.
• Syntax highlighting in PyREPL, and support for color in unittest, argparse, json and calendar CLIs.
• PEP 768: A zero-overhead external debugger interface for CPython.
• UUID versions 6-8 are now supported by the uuid module, and generation of versions 3-5 and 8 are up to 40% faster.
• PEP 765: Disallow return/break/continue that exit a finally block.
• PEP 741: An improved C API for configuring Python.
• A new type of interpreter. For certain newer compilers, this interpreter provides significantly better performance. Opt-in for now, requires building from source.
• Improved error messages.
• Builtin implementation of HMAC with formally verified code from the HACL* project.
• A new command-line interface to inspect running Python processes using asynchronous tasks.
• The pdb module now supports remote attaching to a running Python process.

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

For more details on the changes to Python 3.14, see What’s new in Python 3.14. The next pre-release of Python 3.14 will be the first release candidate, 3.14.0rc1, scheduled for 2025-07-22.

Build changes

• PEP 761: Python 3.14 and onwards no longer provides PGP signatures for release artifacts. Instead, Sigstore is recommended for verifiers.
• Official macOS and Windows release binaries include an experimental JIT compiler.

Incompatible changes, removals and new deprecations

• Incompatible changes
• Python removals and deprecations
• C API removals and deprecations
• Overview of all pending deprecations

Python install manager

The installer we offer for Windows is being replaced by our new install manager, which can be installed from the Windows Store or from its download page. See our documentation for more information. The JSON file available for download below contains the list of all the installable packages available as part of this release, including file URLs and hashes, but is not required to install the latest release. The traditional installer will remain available throughout the 3.14 and 3.15 releases.

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

All this talk of π and yet some say π is wrong. Tau Day (June 28th, 6/28 in the US) celebrates τ as the “true circle constant”, as the ratio of a circle’s circumference to its radius, C/r = 6.283185… The Tau Manifesto declares π “a confusing and unnatural choice for the circle constant”, in part because “2π occurs with astonishing frequency throughout mathematics”.

If you wish to embrace τ the good news is PEP 628 added math.tau to Python 3.6 in 2016:

When working with radians, it is trivial to convert any given fraction of a circle to a value in radians in terms of tau. A quarter circle is tau/4, a half circle is tau/2, seven 25ths is 7*tau/25, etc. In contrast with the equivalent expressions in terms of pi (pi/2, pi, 14*pi/25), the unnecessary and needlessly confusing multiplication by two is gone.

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 cloudy Helsinki, looking forward to Prague and EuroPython next week,

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

Python 3.14.0 beta 3 is here!

It’s 3.14 beta 3!

https://www.python.org/downloads/release/python-3140b3/

This is a beta preview of Python 3.14

Python 3.14 is still in development. This release, 3.14.0b3, is the third of four planned beta releases.

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 3.14 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 2025-07-22). Our goal is to have no ABI changes after beta 4 and as few code changes as possible after the first release candidate. To achieve that, it will be extremely important to get as much exposure for 3.14 as possible during the beta phase.

This includes creating pre-release wheels for 3.14, as it helps other projects to do their own testing. However, we recommend that your regular production releases wait until 3.14.0rc1, to avoid the risk of ABI breaks.

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

Major new features of the 3.14 series, compared to 3.13

Some of the major new features and changes in Python 3.14 are:

New features

Note that PEPs 734 and 779 are exceptionally new in beta 3!

• PEP 779: Free-threaded Python is officially supported
• PEP 649: The evaluation of type annotations is now deferred, improving the semantics of using annotations.
• PEP 750: Template string literals (t-strings) for custom string processing, using the familiar syntax of f-strings.
• PEP 734: Multiple interpreters in the stdlib.
• PEP 784: A new module compression.zstd providing support for the Zstandard compression algorithm.
• PEP 758: except and except* expressions may now omit the brackets.
• Syntax highlighting in PyREPL, and support for color in unittest, argparse, json and calendar CLIs.
• PEP 768: A zero-overhead external debugger interface for CPython.
• UUID versions 6-8 are now supported by the uuid module, and generation of versions 3-5 and 8 are up to 40% faster.
• PEP 765: Disallow return/break/continue that exit a finally block.
• PEP 741: An improved C API for configuring Python.
• A new type of interpreter. For certain newer compilers, this interpreter provides significantly better performance. Opt-in for now, requires building from source.
• Improved error messages.
• Builtin implementation of HMAC with formally verified code from the HACL* project.
• A new command-line interface to inspect running Python processes using asynchronous tasks.
• The pdb module now supports remote attaching to a running Python process.

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

For more details on the changes to Python 3.14, see What’s new in Python 3.14. The next pre-release of Python 3.14 will be the final beta, 3.14.0b4, scheduled for 2025-07-08.

Build changes

• PEP 761: Python 3.14 and onwards no longer provides PGP signatures for release artifacts. Instead, Sigstore is recommended for verifiers.
• Official macOS and Windows release binaries include an experimental JIT compiler.

Incompatible changes, removals and new deprecations

• Incompatible changes
• Python removals and deprecations
• C API removals and deprecations
• Overview of all pending deprecations

Python install manager

The installer we offer for Windows is being replaced by our new install manager, which can be installed from the Windows Store or our FTP page. See our documentation for more information. The JSON file available for download below contains the list of all the installable packages available as part of this release, including file URLs and hashes, but is not required to install the latest release. The traditional installer will remain available throughout the 3.14 and 3.15 releases.

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

If you’re heading out to sea, remember the Maritime Approximation:

π mph = e knots

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 sunny Helsinki with 19 hours of daylight,

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

Python 3.13.5 is now available!

When I was younger we would call this a brown paper bag release, but actually, we shouldn’t hide from our mistakes. We’re only human. So, please enjoy:

Python 3.13.5

 

 https://www.python.org/downloads/release/python-3135/

 

This is the fifth maintenance release of Python 3.13

Python 3.13 is the newest major release of the Python programming language, and it contains many new features and optimizations compared to Python 3.12. 3.13.5 is the fifth maintenance release of 3.13.

3.13.5 is an expedited release to fix a couple of significant issues with the 3.13.4 release:

• gh-135151: Building extension modules on Windows for the regular (non-free-threaded) build failed.
• gh-135171: Generator expressions stopped raising TypeError (when iterating over non-iterable objects) at creation time, delaying it to first use.
• gh-135326: Passing int-like objects (like numpy.int64) to random.getrandbits() failed, when it worked before.

Several other bug fixes (which would otherwise have waited until the next release) are also included. Special thanks to everyone who worked hard the last couple of days to fix these issues as quickly as possible.

Full Changelog

More resources

• Online Documentation
• PEP 719, 3.13 Release Schedule (not that you’ll find this release on there yet.)
• Report bugs via GitHub.
• Help fund Python directly (or via GitHub Sponsors), and support the Python community.

 

Stay safe and upgrade!

As always, upgrading is highly recommended to all users of 3.13.

 

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.

Regards from hey, it’s us again, your release team,
Thomas Wouters
Ned Deily
Steve Dower
Łukasz Langa

Python 3.13.4, 3.12.11, 3.11.13, 3.10.18 and 3.9.23 are now available

 

Python Release Party

It was only meant to be release day for 3.13.4 today, but poor number 13 looked so lonely… And hey, we had a couple of tarfile CVEs that we had to fix. So most of the Release Managers and all the Developers-in-Residence (including Security Developer-in-Residence Seth Michael Larson) came together to make it a full release party.

Security content in these releases

• gh-135034: Fixes multiple issues that allowed tarfile extraction filters (filter="data" and filter="tar") to be bypassed using crafted symlinks and hard links.Addresses CVE 2024-12718, CVE 2025-4138, CVE 2025-4330, and CVE 2025-4517.
• gh-133767: Fix use-after-free in the “unicode-escape” decoder with a non-“strict” error handler.
• gh-128840: Short-circuit the processing of long IPv6 addresses early in ipaddress to prevent excessive memory consumption and a minor denial-of-service.

In addition to the security fixed mentioned above, a few additional changes to the ipaddress were backported to make the security fixes feasible. (See the full changelogs for each release for more details.)

Python 3.13.4

In addition to the security fixes, the fourth maintenance release of Python 3.13 contains more than 300 bugfixes, build improvements and documentation changes.

https://www.python.org/downloads/release/python-3134/

Python 3.12.11

https://www.python.org/downloads/release/python-31211/

Python 3.11.13

 https://www.python.org/downloads/release/python-31113/

Python 3.10.18

https://www.python.org/downloads/release/python-31018/

 

Python 3.9.23

Additional security content in this release (already fixed in older releases for the other versions):

• gh-80222: Fix bug in the folding of quoted strings when flattening an email message using a modern email policy. Previously when a quoted string was folded so that it spanned more than one line, the surrounding quotes and internal escapes would be omitted. This could theoretically be used to spoof header lines using a carefully constructed quoted string if the resulting rendered email was transmitted or re-parsed.

https://www.python.org/downloads/release/python-3923

Stay safe and upgrade!

As always, upgrading is highly recommended to all users of affected versions.

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.

Regards from your very tired tireless release team,
Thomas Wouters
Pablo Galindo Salgado
Łukasz Langa
Ned Deily
Steve Dower

Python 3.14.0 beta 2 is here!

Here’s the second 3.14 beta.

https://www.python.org/downloads/release/python-3140b2/

This is a beta preview of Python 3.14

Python 3.14 is still in development. This release, 3.14.0b2, is the second of four planned beta releases.

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 3.14 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 2025-07-22). Our goal is to have no ABI changes after beta 4 and as few code changes as possible after the first release candidate. To achieve that, it will be extremely important to get as much exposure for 3.14 as possible during the beta phase.

This includes creating pre-release wheels for 3.14, as it helps other projects to do their own testing. However, we recommend that your regular production releases wait until 3.14.0rc1, to avoid the risk of ABI breaks.

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

Major new features of the 3.14 series, compared to 3.13

Some of the major new features and changes in Python 3.14 are:

New features

• PEP 649: The evaluation of type annotations is now deferred, improving the semantics of using annotations.
• PEP 750: Template string literals (t-strings) for custom string processing, using the familiar syntax of f-strings.
• PEP 784: A new module compression.zstd providing support for the Zstandard compression algorithm.
• PEP 758: except and except* expressions may now omit the brackets.
• Syntax highlighting in PyREPL, and support for color in unittest, argparse, json and calendar CLIs.
• PEP 768: A zero-overhead external debugger interface for CPython.
• UUID versions 6-8 are now supported by the uuid module, and generation of versions 3-5 and 8 are up to 40% faster.
• PEP 765: Disallow return/break/continue that exit a finally block.
• PEP 741: An improved C API for configuring Python.
• A new type of interpreter. For certain newer compilers, this interpreter provides significantly better performance. Opt-in for now, requires building from source.
• Improved error messages.
• Builtin implementation of HMAC with formally verified code from the HACL* project.
• A new command-line interface to inspect running Python processes using asynchronous tasks.
• The pdb module now supports remote attaching to a running Python process.

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

For more details on the changes to Python 3.14, see What’s new in Python 3.14. The next pre-release of Python 3.14 will be 3.14.0b3, scheduled for 2025-06-17.

Build changes

• PEP 761: Python 3.14 and onwards no longer provides PGP signatures for release artifacts. Instead, Sigstore is recommended for verifiers.
• Official macOS and Windows release binaries include an experimental JIT compiler.

Incompatible changes, removals and new deprecations

• Incompatible changes
• Python removals and deprecations
• C API removals and deprecations
• Overview of all pending deprecations

Python install manager

The installer we offer for Windows is being replaced by our new install manager, which can be installed from the Windows Store or our FTP page. See our documentation for more information. The JSON file available for download below contains the list of all the installable packages available as part of this release, including file URLs and hashes, but is not required to install the latest release. The traditional installer will remain available throughout the 3.14 and 3.15 releases.

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

In 1897, the State of Indiana almost passed a bill defining π as 3.2.

Of course, it’s not that simple.

Edwin J. Goodwin, M.D., claimed to have come up with a solution to an ancient geometrical problem called squaring the circle, first proposed in Greek mathematics. It involves trying to draw a circle and a square with the same area, using only a compass and a straight edge. It turns out to be impossible because π is transcendental (and this had been proved just 13 years earlier by Ferdinand von Lindemann), but Goodwin fudged things so the value of π was 3.2 (his writings have included at least nine different values of π: including 4, 3.236, 3.232, 3.2325… and even 9.2376…).

Goodwin had copyrighted his proof and offered it to the State of Indiana to use in their educational textbooks without paying royalties, provided they endorsed it. And so Indiana Bill No. 246 was introduced to the House on 18th January 1897. It was not understood and initially referred to the House Committee on Canals, also called the Committee on Swamp Lands. They then referred it to the Committee on Education, who duly recommended on 2nd February that “said bill do pass”. It passed its second reading on the 5th and the education chair moved that they suspend the constitutional rule that required bills to be read on three separate days. This passed 72-0, and the bill itself passed 67-0.

The bill was referred to the Senate on 10th February, had its first reading on the 11th, and was referred to the Committee on Temperance, whose chair on the 12th recommended “that said bill do pass”.

A mathematics professor, Clarence Abiathar Waldo, happened to be in the State Capitol on the day the House passed the bill and walked in during the debate to hear an ex-teacher argue:

The case is perfectly simple. If we pass this bill which establishes a new and correct value for pi , the author offers to our state without cost the use of his discovery and its free publication in our school text books, while everyone else must pay him a royalty.

Waldo ensured the senators were “properly coached”; and on the 12th, during the second reading, after an unsuccessful attempt to amend the bill it was postponed indefinitely. But not before the senators had some fun.

The Indiana News reported on the 13th:

…the bill was brought up and made fun of. The Senators made bad puns about it, ridiculed it and laughed over it. The fun lasted half an hour. Senator Hubbell said that it was not meet for the Senate, which was costing the State $250 a day, to waste its time in such frivolity. He said that in reading the leading newspapers of Chicago and the East, he found that the Indiana State Legislature had laid itself open to ridicule by the action already taken on the bill. He thought consideration of such a proposition was not dignified or worthy of the Senate. He moved the indefinite postponement of the bill, and the motion carried.

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 Helsinki, still light at 10pm,

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

Python 3.14.0 beta 1 is here!

Only one day late, welcome to the first beta!

https://www.python.org/downloads/release/python-3140b1/

This is a beta preview of Python 3.14

Python 3.14 is still in development. This release, 3.14.0b1, is the first of four planned beta releases.

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 3.14 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 2025-07-22). Our goal is to have no ABI changes after beta 4 and as few code changes as possible after the first release candidate. To achieve that, it will be extremely important to get as much exposure for 3.14 as possible during the beta phase.

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

Major new features of the 3.14 series, compared to 3.13

Some of the major new features and changes in Python 3.14 are:

New features

• PEP 649: The evaluation of type annotations is now deferred, improving the semantics of using annotations.
• PEP 750: Template string literals (t-strings) for custom string processing, using the familiar syntax of f-strings.
• PEP 784: A new module compression.zstd providing support for the Zstandard compression algorithm.
• PEP 758: except and except* expressions may now omit the brackets.
• Syntax highlighting in PyREPL, and support for color in unittest, argparse, json and calendar CLIs.
• PEP 768: A zero-overhead external debugger interface for CPython.
• UUID versions 6-8 are now supported by the uuid module, and generation of versions 3-5 and 8 are up to 40% faster.
• PEP 765: Disallow return/break/continue that exit a finally block.
• PEP 741: An improved C API for configuring Python.
• A new type of interpreter. For certain newer compilers, this interpreter provides significantly better performance. Opt-in for now, requires building from source.
• Improved error messages.
• Builtin implementation of HMAC with formally verified code from the HACL* project.

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

For more details on the changes to Python 3.14, see What’s new in Python 3.14. The next pre-release of Python 3.14 will be 3.14.0b2, scheduled for 2025-05-27.

Build changes

• PEP 761: Python 3.14 and onwards no longer provides PGP signatures for release artifacts. Instead, Sigstore is recommended for verifiers.
• Official macOS and Windows release binaries include an experimental JIT compiler.

Incompatible changes, removals and new deprecations

• Incompatible changes
• Python removals and deprecations
• C API removals and deprecations
• Overview of all pending deprecations

Python install manager

The installer we offer for Windows is being replaced by our new install manager, which can be installed from the Windows Store or our FTP page. See our documentation for more information. The JSON file available for download contains the list of all the installable packages available as part of this release, including file URLs and hashes, but is not required to install the latest release. The traditional installer will remain available throughout the 3.14 and 3.15 releases.

More resources

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

Note

During the release process, we discovered a test that only failed when run sequentially and only when run after a certain number of other tests. This appears to be a problem with the test itself, and we will make it more robust for beta 2. For details, see python/cpython#133532.

And now for something completely different

The mathematical constant pi is represented by the Greek letter π and represents the ratio of a circle’s circumference to its diameter. The first person to use π as a symbol for this ratio was Welsh self-taught mathematician William Jones in 1706. He was a farmer’s son born in Llanfihangel Tre’r Beirdd on Angelsy (Ynys Môn) in 1675 and only received a basic education at a local charity school. However, the owner of his parents’ farm noticed his mathematical ability and arranged for him to move to London to work in a bank.

By age 20, he served at sea in the Royal Navy, teaching sailors mathematics and helping with the ship’s navigation. On return to London seven years later, he became a maths teacher in coffee houses and a private tutor. In 1706, Jones published Synopsis Palmariorum Matheseos which used the symbol π for the ratio of a circle’s circumference to diameter (hunt for it on pages 243 and 263 or here). Jones was also the first person to realise π is an irrational number, meaning it can be written as decimal number that goes on forever, but cannot be written as a fraction of two integers.

But why π? It’s thought Jones used the Greek letter π because it’s the first letter in perimetron or perimeter. Jones was the first to use π as our familiar ratio but wasn’t the first to use it in as part of the ratio. William Oughtred, in his 1631 Clavis Mathematicae (The Key of Mathematics), used π/δ to represent what we now call pi. His π was the circumference, not the ratio of circumference to diameter. James Gregory, in his 1668 Geometriae Pars Universalis (The Universal Part of Geometry) used π/ρ instead, where ρ is the radius, making the ratio 6.28… or τ. After Jones, Leonhard Euler had used π for 6.28…, and also p for 3.14…, before settling on and popularising π for the famous ratio.

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 Helsinki as the leaves begin to appear on the trees,

Your release team,

Hugo van Kemenade
Ned Deily
Steve Dower
Łukasz Langa

Python 3.14.0a7, 3.13.3, 3.12.10, 3.11.12, 3.10.17 and 3.9.22 are now available

Not one, not two, not three, not four, not five, but six releases! Is this the most in a single day?

3.12-3.14 were regularly scheduled, and we had some security fixes to release in 3.9-3.11 so let’s make a big day of it. This also marks the last bugfix release of 3.12 as it enters the security-only phase. See devguide.python.org/versions/ for a chart.

Python 3.14.0a7

Here comes the final alpha! This means we have just four weeks until the first beta to get those last features into 3.14 before the feature freeze on 2025-05-06!

https://www.python.org/downloads/release/python-3140a7/

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, 3.14.0a7, is the last 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 758: Allow except and except* expressions without parentheses
• PEP 761: Python 3.14 and onwards no longer provides PGP signatures for release artifacts. Instead, Sigstore is recommended for verifiers.
• PEP 765: disallow return/break/continue that exit a finally block
• PEP 768: Safe external debugger interface for CPython
• A new type of interpreter. For certain newer compilers, this interpreter provides significantly better performance. Opt-in for now, requires building from source.
• UUID versions 6-8 are now supported by the uuid module, and generation of versions 3-5 and 8 are up to 40% faster.
• Improved error messages
• 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 first beta, 3.14.0b1, currently scheduled for 2025-05-06. After this, no new features can be added but bug fixes and docs improvements are allowed – and encouraged!

Python 3.13.3

This is the third maintenance release of Python 3.13.

Python 3.13 is the newest major release of the Python programming language, and it contains many new features and optimizations compared to Python 3.12. 3.13.3 is the latest maintenance release, containing almost 320 bugfixes, build improvements and documentation changes since 3.13.2.

https://www.python.org/downloads/release/python-3133/

Python 3.12.10

This is the tenth maintenance release of Python 3.12.

Python 3.12.10 is the latest maintenance release of Python 3.12, and the last full maintenance release. Subsequent releases of 3.12 will be security-fixes only. This last maintenance release contains about 230 bug fixes, build improvements and documentation changes since 3.12.9.

https://www.python.org/downloads/release/python-31210/

Python 3.11.12

This is a security release of Python 3.11:

• gh-106883: Fix deadlock in threaded application when using sys._current_frames
• gh-131809: Upgrade vendored expat to 2.7.1
• gh-80222: Folding of quoted string in display_name violates RFC
• gh-121284: Invalid RFC 2047 address header after refolding with email.policy.default
• gh-131261: Update libexpat to 2.7.0
• gh-105704: [CVE-2025-0938] urlparse does not flag hostname containing [ or ] as incorrect
• gh-119511: OOM vulnerability in the imaplib module

https://www.python.org/downloads/release/python-31112/

Python 3.10.17

This is a security release of Python 3.10:

• gh-131809: Upgrade vendored expat to 2.7.1
• gh-80222: Folding of quoted string in display_name violates RFC
• gh-121284: Invalid RFC 2047 address header after refolding with email.policy.default
• gh-131261: Update libexpat to 2.7.0
• gh-105704: CVE-2025-0938 urlparse does not flag hostname containing [ or ] as incorrect
• gh-119511: OOM vulnerability in the imaplib module

https://www.python.org/downloads/release/python-31017/

Python 3.9.22

This is a security release of Python 3.9:

• gh-131809 and gh-131261: Upgrade vendored expat to 2.7.1
• gh-121284: Invalid RFC 2047 address header after refolding with email.policy.default
• gh-105704: CVE-2025-0938 urlparse does not flag hostname containing [ or ] as incorrect
• gh-119511: OOM vulnerability in the imaplib module

https://www.python.org/downloads/release/python-3922/

Please upgrade! Please test!

We highly recommend upgrading 3.9-3.13 and we encourage you to test 3.14.

And now for something completely different

On Saturday, 5th April, 3.141592653589793 months of the year had elapsed.

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 organisation contributions to the Python Software Foundation.

Regards from a sunny and cold Helsinki springtime,

Your full release team,

Hugo van Kemenade
Thomas Wouters
Pablo Galindo Salgado
Łukasz Langa
Ned Deily
Steve Dower

Python 3.14.0 alpha 6 is out

Here comes the penultimate alpha.

https://www.python.org/downloads/release/python-3140a6/

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, 3.14.0a6, is the sixth 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.
• UUID versions 6-8 are now supported by the uuid module, and generation of versions 3-5 and 8 are up to 40% faster.
• 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 final alpha, 3.14.0a7, currently scheduled for 2025-04-08.

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

March 14 is celebrated as pi day, because 3.14 is an approximation of π. The day is observed by eating pies (savoury and/or sweet) and celebrating π. The first pi day was organised by physicist and tinkerer Larry Shaw of the San Francisco Exploratorium in 1988. It is also the International Day of Mathematics and Albert Einstein’s birthday. Let’s all eat some pie, recite some π, install and test some py, and wish a happy birthday to Albert, Loren and all the other pi day children!

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 Helsinki as fresh snow falls,

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

Python 3.14.0 alpha 5 is out

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

Python 3.13.2 and 3.12.9 now available!

 

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.

Python 3.13.2

Python 3.13’s second maintenance release. About 250 changes went into this update, and can be yours for free if you just upgrade now.

https://www.python.org/downloads/release/python-3132/

Python 3.12.9

Python 3.12’s ninth maintenance release already. Just 180 changes for 3.12, but it’s still worth upgrading.

https://www.python.org/downloads/release/python-3129/

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.

Regards from your tireless, tireless release team,
Thomas Wouters
Ned Deily
Steve Dower
Łukasz Langa

Python 3.14.0 alpha 4 is out

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
Ned Deily
Steve Dower
Łukasz Langa