Python Insider

Join the Python Security Response Team!

2026-02-17T02:30:00.001-05:00

Thanks to the work of the Security Developer-in-Residence Seth Larson, the Python Security Response Team (PSRT) now has an approved public governance document (PEP 811). Following the new governance structure the PSRT now publishes a public list of members, has documented responsibilities for members and admins, and a defined process for onboarding and offboarding members to balance the needs of security and sustainability. The document also clarifies the relationship between the Python Steering Council and the PSRT.

And this new onboarding process is already working! The PSF Infrastructure Engineer, Jacob Coffee, has just joined the PSRT as the first new non-"Release Manager" member since Seth joined the PSRT in 2023. We expect new members to join further bolstering the sustainability of security work for the Python programming language.

Thanks to Alpha-Omega for their support of Python ecosystem security by sponsoring Seth’s work as the Security Developer-in-Residence at the Python Software Foundation.

What is the Python Security Response Team?

Security doesn't happen by accident: it's thanks to the work of volunteers and paid Python Software Foundation staff on the Python Security Response Team to triage and coordinate vulnerability reports and remediations keeping all Python users safe. Just last year the PSRT published 16 vulnerability advisories for CPython and pip, the most in a single year to date!

And the PSRT usually can’t do this work alone, PSRT coordinators are encouraged to involve maintainers and experts on the projects and submodules. By involving the experts directly in the remediation process ensures fixes adhere to existing API conventions and threat-models, are maintainable long-term, and have minimal impact on existing use-cases.

Sometimes the PSRT even coordinates with other open source projects to avoid catching the Python ecosystem off-guard by publishing a vulnerability advisory that affects multiple other projects. The most recent example of this is PyPI’s ZIP archive differential attack mitigation.

This work deserves recognition and celebration just like contributions to source code and documentation. Seth and Jacob are developing further improvements to workflows involving “GitHub Security Advisories” to record the reporter, coordinator, and remediation developers and reviewers to CVE and OSV records to properly thank everyone involved in the otherwise private contribution to open source projects.

How can I join the Python Security Response Team?

Maybe you’ve read all this and are interested in directly helping the Python programming language be more secure! The process is similar to the Core Team nomination process, you need an existing PSRT member to nominate you and for your nomination to receive at least ⅔ positive votes from existing PSRT members.

You do not need to be a core developer, team member, or triager to be a member of the Python Security Response Team. Anyone with security expertise that is known and highly-trusted within the Python community and has time to volunteer or donate through their employer would make a good candidate for the PSRT. Please note that all PSRT team members have documented responsibilities and are expected to contribute meaningfully to the remediation of vulnerabilities.

Being a member of the PSRT is not required to be notified of vulnerabilities and shouldn’t be to receive “early notification” of vulnerabilities affecting CPython and pip. The Python Software Foundation is a CVE Numbering Authority and publishes CVE and OSV records with up-to-date information about vulnerabilities affecting CPython and pip.

Python 3.15.0 alpha 6

2026-02-11T10:42:00.003-05:00

This is an early developer preview of Python 3.15

www.python.org/downloads/release/python-3150a6/

Major new features of the 3.15 series, compared to 3.14

Python 3.15 is still in development. This release, 3.15.0a6, is the sixth of eight 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 (2026-05-05) and, if necessary, may be modified or deleted up until the release candidate phase (2026-07-28). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.15 are still being planned and written. Among the new major new features and changes so far:

PEP 799: A new high-frequency, low-overhead, statistical sampling profiler and dedicated profiling package
PEP 798: Unpacking in comprehensions with * and **
PEP 686: Python now uses UTF-8 as the default encoding
PEP 782: A new PyBytesWriter C API to create a Python bytes object
PEP 728: TypedDict with typed extra items
The JIT compiler has been significantly upgraded, with 3-4% geometric mean performance improvement on x86-64 Linux over the standard interpreter, and 7-8% speedup on AArch64 macOS over the tail-calling interpreter
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 3.15 will be 3.15.0a7, currently scheduled for 2026-03-10.

More resources

Online documentation
PEP 790, 3.15 release schedule
Report bugs at github.com/python/cpython/issues
Help fund Python directly (or via GitHub Sponsors) and support the Python community

And now for something completely different

By reason of these things, then, the whaling voyage was welcome; the great flood-gates of the wonder-world swung open, and in the wild conceits that swayed me to my purpose, two and two there floated into my inmost soul, endless processions of the whale, and, mid most of them all, one grand hooded phantom, like a snow hill in the air.

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 as the snow slowly falls in Helsinki,

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

Python 3.14.3 and 3.13.12 are now available!

2026-02-03T17:08:00.002-05:00

Python 3.14.3 is now available!

This is third maintenance release of Python 3.14

Python 3.14.3 is the third maintenance release of 3.14, containing around 299 bugfixes, build improvements and documentation changes since 3.14.2.

https://www.python.org/downloads/release/python-3143/

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 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.

For more details on the changes to Python 3.14, see What’s new in Python 3.14.

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.
Official Android binary releases are now available.

Incompatible changes, removals and new 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 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 directly (or via GitHub Sponsors) and support the Python community

And now for something almost, but not quite, completely different

Python 3.13.12 is also now available!

https://www.python.org/downloads/release/python-31312/

This is the twelfth maintenance release of Python 3.13

Python 3.13.12 is the twelfth maintenance release of 3.13, containing around 250 bugfixes, build improvements and documentation changes since 3.13.11.

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 an international releasing task force spread out over a whopping 10 timezones this time,

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

Python 3.15.0 alpha 5 (yes, another alpha!)

2026-01-14T12:38:00.006-05:00

Note: 3.15.0a4 was accidentally built against main from 2025-12-23 instead of 2026-01-13, so this 3.15.0a5 is an extra release correctly built against 2026-01-14.

This is an early developer preview of Python 3.15

www.python.org/downloads/release/python-3150a5/

Major new features of the 3.15 series, compared to 3.14

Python 3.15 is still in development. This release, 3.15.0a5, is the fifth of ~~seven~~ eight 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.

Many new features for Python 3.15 are still being planned and written. Among the new major new features and changes so far:

PEP 799: A new high-frequency, low-overhead, statistical sampling profiler and dedicated profiling package
PEP 686: Python now uses UTF-8 as the default encoding
PEP 782: A new PyBytesWriter C API to create a Python bytes object
The JIT compiler has been significantly upgraded, with 4-5% geometric mean performance improvement on x86-64 Linux over the standard interpreter, and 7-8% speedup on AArch64 macOS over the tail-calling interpreter
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 3.15 will be 3.15.0a6, currently scheduled for 2026-02-10.

More resources

Online documentation
PEP 790, 3.15 release schedule
Report bugs at https://github.com/python/cpython/issues
Help fund Python directly (or via GitHub Sponsors) and support the Python community

And now for something completely different

At last it was given out that some time next day the ship would certainly sail. So next morning, Queequeg and I took a very early start.

Enjoy the new release

Regards from a still snowfully subzero Helsinki,

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

Python 3.15.0 alpha 4

2026-01-13T15:24:00.003-05:00

Edit: This 3.15.0a4 was accidentally built against `main` from 2025-12-23 instead of 2026-01-13, so 3.15.0a5 is an extra release correctly built against 2026-01-14.

This is an early developer preview of Python 3.15

www.python.org/downloads/release/python-3150a4/

Major new features of the 3.15 series, compared to 3.14

Python 3.15 is still in development. This release, 3.15.0a4, 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.

Many new features for Python 3.15 are still being planned and written. Among the new major new features and changes so far:

PEP 799: A new high-frequency, low-overhead, statistical sampling profiler and dedicated profiling package
PEP 686: Python now uses UTF-8 as the default encoding
PEP 782: A new PyBytesWriter C API to create a Python bytes object
The JIT compiler has been significantly upgraded, with 3-4% geometric mean performance improvement on x86-64 Linux over the standard interpreter, and 7-8% speedup on AArch64 macOS over the tail-calling interpreter
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 3.15 will be 3.15.0a5, currently scheduled for 2026-02-10.

More resources

Online documentation
PEP 790, 3.15 release schedule
Report bugs at https://github.com/python/cpython/issues
Help fund Python directly (or via GitHub Sponsors) and support the Python community

And now for something completely different

Upon this every soul was confounded; for the phenomenon just then observed by Ahab had unaccountably escaped every one else; but its very blinding palpableness must have been the cause.

Thrusting his head half way into the binnacle, Ahab caught one glimpse of the compasses; his uplifted arm slowly fell; for a moment he almost seemed to stagger. Standing behind him Starbuck looked, and lo! the two compasses pointed East, and the Pequod was as infallibly going West.

But ere the first wild alarm could get out abroad among the crew, the old man with a rigid laugh exclaimed, “I have it! It has happened before. Mr. Starbuck, last night’s thunder turned our compasses—that’s all. Thou hast before now heard of such a thing, I take it.”

“Aye; but never before has it happened to me, sir,” said the pale mate, gloomily.

Enjoy the new release

Regards from a snowfully subzero Helsinki,

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

Python 3.15.0 alpha 3

2025-12-16T09:44:00.004-05:00

This is an early developer preview of Python 3.15

www.python.org/downloads/release/python-3150a3/

Major new features of the 3.15 series, compared to 3.14

Python 3.15 is still in development. This release, 3.15.0a3, is the third 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.

Many new features for Python 3.15 are still being planned and written. Among the new major new features and changes so far:

PEP 799: A new high-frequency, low-overhead, statistical sampling profiler and dedicated profiling package
PEP 686: Python now uses UTF-8 as the default encoding
PEP 782: A new PyBytesWriter C API to create a Python bytes object
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 3.15 will be 3.15.0a4, currently scheduled for 2026-01-13.

More resources

Online documentation
PEP 790, 3.15 release schedule
Report bugs at https://github.com/python/cpython/issues
Help fund Python directly (or via GitHub Sponsors) and support the Python community

And now for something completely different

Instantly the captain ran forward, and in a loud voice commanded his crew to desist from hoisting the cutting-tackles, and at once cast loose the cables and chains confining the whales to the ship.

“What now?” said the Guernsey-man, when the Captain had returned to them.

“Why, let me see; yes, you may as well tell him now that—that—in fact, tell him I’ve diddled him, and (aside to himself) perhaps somebody else.”

Enjoy the new release

Regards from an even deeper darker Helsinki,

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

Python 3.14.2 and 3.13.11 are now available!

2025-12-05T16:29:00.001-05:00

Two more, just three days after the last? Yes!

We found some regressions, so here’s an expedited pair of releases. They also come with some bonus security fixes.

Python 3.14.2

www.python.org/downloads/release/python-3142/

Python 3.14.2 is the second maintenance release of 3.14, containing 18 bugfixes, build improvements and documentation changes since 3.14.1.

This is an expedited release to fix the following regressions:

gh-142206: Exceptions in multiprocessing in running programs while upgrading Python.
gh-142214: Exceptions in dataclasses without __init__ method.
gh-142218: Segmentation faults and assertion failures in insertdict.
gh-140797: Crash when using multiple capturing groups in re.Scanner

And these security fixes:

gh-142145: Remove quadratic behavior in node ID cache clearing (CVE-2025-12084)
gh-119452: Fix a potential virtual memory allocation denial of service in http.server

See the full changelog.

Python 3.13.11

www.python.org/downloads/release/python-31311/

Python 3.13.11 is the eleventh maintenance release of 3.13. This is an expedited release to fix the following regressions:

gh-142206: Exceptions in multiprocessing in running programs while upgrading Python.
gh-142218: Segmentation faults and assertion failures in insertdict.
gh-140797: Crash when using multiple capturing groups in re.Scanner

And these security fixes:

gh-142145: Remove quadratic behavior in node ID cache clearing (CVE-2025-12084)
gh-119451: Fix a potential denial of service in http.client
gh-119452: Fix a potential virtual memory allocation denial of service in http.server

See the full changelog.

Enjoy the new release

Regards from deeper darker Helsinki,

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

Python 3.13.10 is now available, too, you know!

2025-12-02T13:50:00.005-05:00

The latest version of Python 3.13 is now available!

Python 3.13.10

This is the tenth maintenance release of Python 3.13

Python 3.13.10 is the tenth maintenance release of 3.13, containing around 300 bugfixes, build improvements and documentation changes since 3.13.9.

Full Changelog

More resources

Online Documentation
PEP 719, 3.13 Release Schedule
Report bugs at https://github.com/python/cpython/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.

Regards from your package managers,

Thomas Wouters
Ned Deily
Steve Dower
Łukasz Langa

Python 3.14.1 is now available!

2025-12-02T11:43:00.001-05:00

This is first maintenance release of Python 3.14

Python 3.14.1 is the first maintenance release of 3.14, containing around 558 bugfixes, build improvements and documentation changes since 3.14.0.

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 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.

For more details on the changes to Python 3.14, see What’s new in Python 3.14.

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.
Official Android binary releases are now available.

Incompatible changes, removals and new deprecations

Python install manager

More resources

Online documentation
PEP 745, 3.14 Release Schedule
Report bugs at github.com/python/cpython/issues
Help fund Python directly (or via GitHub Sponsors) and support the Python community

And now for something completely different

Seki Takakazu (関孝和; c. March 1642 – December 5, 1708) was a Japanese mathematician and samurai who laid the foundations of Japanese mathematics, later known as wasan (和算, from wa (“Japanese”) and san (“calculation”).

Seki was a contemporary of Isaac Newton and Gottfried Leibniz but worked independently. He created a new algebraic system, worked on infinitesimal calculus, and is credited with the discovery of Bernoulli numbers (before Bernoulli’s birth).

Seki also calculated π to 11 decimal places using a polygon with 131,072 sides inscribed within a circle, using an acceleration method now known as Aitken’s delta-squared process, which was rediscovered by Alexander Aitken in 1926.

Enjoy the new release

Regards from deepest darkest Helsinki,

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

Python 3.15.0 alpha 2

2025-11-19T04:56:00.002-05:00

This is an early developer preview of Python 3.15

https://www.python.org/downloads/release/python-3150a2/

Major new features of the 3.15 series, compared to 3.14

Python 3.15 is still in development. This release, 3.15.0a2, 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.

Many new features for Python 3.15 are still being planned and written. Among the new major new features and changes so far:

PEP 799: A new high-frequency, low-overhead, statistical sampling profiler and dedicated profiling package
PEP 686: Python now uses UTF-8 as the default encoding
PEP 782: A new PyBytesWriter C API to create a Python bytes object
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 3.15 will be 3.15.0a3, currently scheduled for 2025-12-16.

More resources

Online documentation
PEP 790, 3.15 release schedule
Report bugs at https://github.com/python/cpython/issues
Help fund Python directly (or via GitHub Sponsors) and support the Python community

And now for something completely different

“An hour,” said Ahab, standing rooted in his boat’s stern; and he gazed beyond the whale’s place, towards the dim blue spaces and wide wooing vacancies to leeward. It was only an instant; for again his eyes seemed whirling round in his head as he swept the watery circle. The breeze now freshened; the sea began to swell.

“The birds!—the birds!” cried Tashtego.

Enjoy the new release

Regards from a crisp and sunny subzero Helsinki,

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

Python 3.15.0 alpha 1

2025-10-15T02:13:00.000-04:00

This is an early developer preview of Python 3.15

https://www.python.org/downloads/release/python-3150a1/

Major new features of the 3.15 series, compared to 3.14

Python 3.15 is still in development. This release, 3.15.0a1, 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.

Many new features for Python 3.15 are still being planned and written. Among the new major new features and changes so far:

PEP 799: A dedicated profiling package for Python profiling tools
PEP 686: Python now uses UTF-8 as the default encoding
PEP 782: A new PyBytesWriter C API to create a Python bytes object
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 3.15 will be 3.15.0a2, currently scheduled for 2025-11-18.

More resources

Online documentation
PEP 790, 3.15 Release Schedule
Report bugs at https://github.com/python/cpython/issues
Help fund Python directly (or via GitHub Sponsors) and support the Python community

And now for something completely different

And hence not only at substantiated times, upon well known separate feeding-grounds, could Ahab hope to encounter his prey; but in crossing the widest expanses of water between those grounds he could, by his art, so place and time himself on his way, as even then not to be wholly without prospect of a meeting.

Enjoy the new release

Regards from Helsinki before the first PyCon Finland in 9 years,

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

Python 3.13.9 is now available!

2025-10-14T15:07:00.004-04:00

Python 3.13.9

https://www.python.org/downloads/release/python-3139/

3.13.9 is an expedited release containing a fix for one specific regression in Python 3.13.8:

gh-139783: Fix inspect.getsourcelines for the case when a decorator is followed by a comment or an empty line.

There are no other changes in this release, compared to 3.13.8.

More resources

3.13 online documentation
PEP 745, 3.13 release schedule
Report bugs at github.com/python/cpython/issues
Help fund Python and its community

Enjoy the new releases

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

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

Python 3.12.12, 3.11.14, 3.10.19 and 3.9.24 are now available!

2025-10-09T17:00:00.004-04:00

Old-timer Release Party

We couldn’t just let Hugo have fun with 3.14.0, so here are new security releases of the venerated Python versions, 3.12 through 3.9!

Security content in these releases

XML-related

gh-139312: Upgraded bundled libexpat to 2.7.3 to fix CVE-2025-59375
gh-139400: xml.parsers.expat: Made sure that parent Expat parsers are only garbage-collected once they are no longer referenced by subparsers created by ExternalEntityParserCreate().

Archive-related

gh-130577: tarfile now validates archives to ensure member offsets are non-negative.
gh-139700: Now checking consistency of the zip64 end of central directory record. Added support for records with “zip64 extensible data” if there are no bytes prepended to the ZIP file.

HTML parsing-related

gh-135661: Fixed parsing start and end tags in html.parser.HTMLParser according to the HTML5 standard.
Whitespaces no longer accepted between </ and the tag name. E.g. </ script> does not end the script section.
Vertical tabulation (\v) and non-ASCII whitespaces no longer recognized as whitespaces. The only whitespaces are \t\n\r\f and space.
Null character (U+0000) no longer ends the tag name.
Attributes and slashes after the tag name in end tags are now ignored, instead of terminating after the first > in quoted attribute value. E.g. </script/foo=">"/>.
Multiple slashes and whitespaces between the last attribute and closing > are now ignored in both start and end tags. E.g. <a foo=bar/ //>.
Multiple = between attribute name and value are no longer collapsed. E.g. <a foo==bar> produces attribute “foo” with value “=bar”.
gh-135661: Fixed CDATA section parsing in html.parser.HTMLParser according to the HTML5 standard: ] ]> and ]] > no longer end the CDATA section. Add private method _set_support_cdata() which can be used to specify how to parse <[CDATA[ — as a CDATA section in foreign content (SVG or MathML) or as a bogus comment in the HTML namespace.
gh-102555: Fixed comment parsing in html.parser.HTMLParser according to the HTML5 standard. --!> now ends the comment. -- > no longer ends the comment. Support abnormally ended empty comments <--> and <--->.
gh-135462: Fixed quadratic complexity in processing specially crafted input in html.parser.HTMLParser. End-of-file errors are now handled according to the HTML5 specs – comments and declarations are automatically closed, tags are ignored.
gh-118350: Fixed support of escapable raw text mode (elements “textarea” and “title”) in html.parser.HTMLParser.
gh-86155: html.parser.HTMLParser.close() no longer loses data when the <script> tag is not closed.

Python 3.12.12

Python 3.11.14

Additional security content in this release:

gh-135374: Update the bundled copy of setuptools to 79.0.1 to fix CVE-2025-47273 and CVE-2024-6345.

Python 3.10.19

Additional security content in this release:

gh-135374: Update the bundled copy of setuptools to 79.0.1 to fix CVE-2025-47273 and CVE-2024-6345.

Python 3.9.24

Additional security content in this release:

gh-135374: Update the bundled copy of setuptools to 79.0.1 to fix CVE-2025-47273 and CVE-2024-6345.
gh-121227: Raise an SSL.SSLError if an empty protocols argument is passed to ssl.SSLContext.set_npn_protocols() to fix CVE-2024-5642

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 old~~ tireless release team,
Thomas Wouters
Pablo Galindo Salgado
Łukasz Langa
Ned Deily
Steve Dower

Python 3.14.0 (final) is here!

2025-10-07T11:09:00.001-04:00

Python 3.14.0 is now available

python.org/downloads/release/python-3140/

This is the stable release of Python 3.14.0

Python 3.14.0 is the newest major release of the Python programming language, and it contains many new features and optimisations compared to Python 3.13.

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 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.

For more details on the changes to Python 3.14, see What’s new in Python 3.14.

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.
Official Android binary releases are now available.

Incompatible changes, removals and new deprecations

Python install manager

More resources

Online documentation
PEP 745, 3.14 Release Schedule
Report bugs at github.com/python/cpython/issues
Help fund Python directly (or via GitHub Sponsors) and support the Python community

And now for something completely different

Edgar Allen Poe died on 7th October 1849.

As we all recall from 3.14.0a1, piphilology is the creation of mnemonics to help memorise the digits of π, and the number of letters in each word in a pi-poem (or “piem”) successively correspond to the digits of π.

In 1995, Mike Keith, an American mathematician and author of constrained writing, retold Poe’s The Raven as a 740-word piem. Here’s the first two stanzas of Near A Raven:

            Poe, E.
      Near a Raven

Midnights so dreary, tired and weary.
    Silently pondering volumes extolling all by-now obsolete lore.
During my rather long nap - the weirdest tap!
    An ominous vibrating sound disturbing my chamber’s antedoor.
        “This”, I whispered quietly, “I ignore”.
Perfectly, the intellect remembers: the ghostly fires, a glittering ember.
    Inflamed by lightning’s outbursts, windows cast penumbras upon this floor.
Sorrowful, as one mistreated, unhappy thoughts I heeded:
    That inimitable lesson in elegance - Lenore -
        Is delighting, exciting…nevermore.

Enjoy the new release

Regards from a colourful autumnal Helsinki,

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

Python 3.13.8 is now available

2025-10-07T10:42:00.000-04:00

The latest version of Python 3.13 is now available!

Python 3.13.8

This is the eighth maintenance release of Python 3.13

Python 3.13 is the ~~newest~~ previous major release of the Python programming language, and it contains many new features and optimizations compared to Python 3.12. 3.13.8 is the eighth maintenance release of 3.13, containing around 200 bugfixes, build improvements and documentation changes since 3.13.7.

Full Changelog

More resources

Online Documentation
PEP 719, 3.13 Release Schedule
Report bugs at https://github.com/python/cpython/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.

Regards from your package managers,

Thomas Wouters
Ned Deily
Steve Dower
Łukasz Langa

Python 3.14.0rc3 is go!

2025-09-18T08:06:00.003-04:00

It’s 🪄 finally 🪄 the final 3.14 release candidate!

https://www.python.org/downloads/release/python-3140rc3/

Note: It’s another magic release. We fixed another bug that required bumping the magic number stored in Python bytecode (.pyc) files. This means file .pyc files created for rc2 cannot be used for rc3, and they’ll be recompiled.

The ABI isn’t changing. Wheels built for rc1 should be fine for rc2, rc3 and 3.14.x, so this shouldn’t affect too many people.

This release, 3.14.0rc3, is the final 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 next release of Python 3.14 will be the final release, 3.14.0, 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 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 3.14.0 release candidates 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 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.

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.
Official Android binary releases are now available.

Incompatible changes, removals and new 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

According to Pablo Galindo Salgado at PyCon Greece:

There are things that are supercool indeed, like for instance, this is one of the results that I’m more proud about. This equation over here, which you don’t need to understand, you don’t need to be scared about, but this equation here tells what is the maximum time that it takes for a ray of light to fall into a black hole. And as you can see the math is quite complicated but the answer is quite simple: it’s 2π times the mass of the black hole. So if you normalise by the mass of the black hole, the answer is 2π. And because there is nothing specific about your election of things in this formula, this formula is universal. It means it doesn’t depend on anything other than nature itself. Which means that you can use this as a definition of π. This is a valid alternative definition of the number π. It’s literally half the maximum time it takes to fall into a black hole, which is kind of crazy. So next time someone asks you what π means you can just drop this thing and impress them quite a lot. Maybe Hugo could use this information to put it into the release notes of πthon [yes, I can, thank you!].

Enjoy the new release

Regards from wonderful Cambridge,

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

Python 3.14.0rc2 and 3.13.7 are go!

2025-08-14T15:15:00.005-04:00

Not one but two expedited releases! 🎉 🎉

Python 3.14.0rc2

It’s the final 🪄 penultimate 🪄 3.14 release candidate!

https://www.python.org/downloads/release/python-3140rc2/

Note: rc2 was originally planned for 2025-08-26, but we fixed a bug that required bumping the magic number stored in Python bytecode (.pyc) files. This means .pyc files created for rc1 cannot be used for rc2, and they’ll be recompiled.

The ABI isn’t changing. Wheels built for rc1 should be fine for rc2, rc3 and 3.14.x. So this shouldn’t affect too many people but let’s get this out for testing sooner.

Due to this early release, we’ll also add a third release candidate between now and the final 3.14.0 release, with no planned change to the final release date.

This release, 3.14.0rc2, 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 next pre-release of Python 3.14 will be the final release candidate, 3.14.0rc3, scheduled for 2025-09-16; 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

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 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.

Build changes

Note that Android binaries are new in rc2!

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 experimentalJIT compiler.
Official Android binary releases are now available.

Incompatible changes, removals and new 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.

Python 3.13.7

This is the seventh maintenance release of Python 3.13

https://www.python.org/downloads/release/python-3137/

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. 3.13.7 is the seventh maintenance release of 3.13.

3.13.7 is an expedited release to fix a significant issue with the 3.13.6 release:

gh-137583: Regression in ssl module between 3.13.5 and 3.13.6: reading from a TLS-encrypted connection blocks

A few other bug fixes (which would otherwise have waited until the next release) are also included.

More resources

3.14 online documentation
3.13 online documentation
PEP 719, 3.14 release schedule
PEP 745, 3.13 release schedule
Report bugs at github.com/python/cpython/issues
Help fund Python and its community

And now for something completely different

The magpie, Pica pica in Latin, is a black and white bird in the crow family, known for its chattering call.

The first-known use in English is from a 1589 poem, where magpie is spelled “magpy” and cuckoo is “cookow”:

Th[e]y fly to wood like breeding hauke,
  And leave old neighbours loue,
They pearch themselves in syluane lodge,
  And soare in th' aire aboue.
There : magpy teacheth them to chat,
  And cookow soone doth hit them pat.

The name comes from Mag, short for Margery or Margaret (compare robin redbreast, jenny wren, and its corvid relative jackdaw); and pie, a magpie or other bird with black and white (or pied) plumage. The sea-pie (1552) is the oystercatcher, the grey pie (1678) and murdering pie (1688) is the great grey shrike. Others birds include the yellow and black pie, red-billed pie, wandering tree-pie, and river pie. The rain-pie, wood-pie and French pie are woodpeckers.

Pie on its own dates to before 1225, and comes from the Latin name for the bird, pica.

Enjoy the new releases

Regards from a busy Helsinki on Night of the Arts,

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

Python 3.13.6 is now available

2025-08-06T17:35:00.000-04:00

The latest version of Python 3.13 is now available!

Python 3.13.6

This is the sixth 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. 3.13.6 is the sixth maintenance release of 3.13, containing around 200 bugfixes, build improvements and documentation changes since 3.13.5.

Full Changelog

More resources

Online Documentation
PEP 719, 3.13 Release Schedule
Report bugs at https://github.com/python/cpython/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, especially now.

Regards from your package managers,

Thomas Wouters
Ned Deily
Steve Dower
Łukasz Langa

Python 3.14 release candidate 1 is go!

2025-07-22T15:47:00.004-04:00

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 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

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

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!

2025-07-08T11:04:00.001-04:00

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

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

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!

2025-06-17T14:43:00.008-04:00

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.

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

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

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!

2025-06-11T18:03:00.001-04:00

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

2025-06-03T17:04:00.002-04:00

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

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.

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!

2025-05-26T15:35:00.002-04:00

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.

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

Python install manager

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

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!

2025-05-07T13:34:00.003-04:00

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.

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

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

Regards from Helsinki as the leaves begin to appear on the trees,

Your release team,

Hugo van Kemenade
Ned Deily
Steve Dower
Łukasz Langa