Thursday, July 30, 2020

Upgrade to pip 20.2, plus, changes coming in 20.3

On behalf of the Python Packaging Authority, I am pleased to announce that we have just released pip 20.2, a new version of pip. You can install it by running python -m pip install --upgrade pip.

The highlights for this release are:

- The beta of the next-generation dependency resolver is available -- please test
- Faster installations from wheel files
- Improved handling of wheels containing non-ASCII file contents
- Faster pip list using parallelized network operations
- Installed packages now contain metadata about whether they were directly requested by the user (PEP 376’s REQUESTED file)

The new dependency resolver is off by default because it is in beta and not yet ready for everyday use. The new dependency resolver is significantly stricter and more consistent when it receives incompatible instructions, and reduces support for certain kinds of constraints files, so some workarounds and workflows may break. Please test it with the --use-feature=2020-resolver flag. Please see our guide on how to test and migrate, how to report issues, and context for the change.

Please report bugs through the resolver testing survey.

Thanks to all who tested the alpha of the new resolver in pip 20.1 for feedback that helped us get it to the beta stage.

We are preparing to change the default dependency resolution behavior and make the new resolver the default in pip 20.3 (in October 2020).

This release also partially optimizes pip’s network usage during installation (as part of a Google Summer of Code project by McSinyx). Please test it with pip install --use-feature=2020-resolver --use-feature=fast-deps and report bugs to the issue tracker. This functionality is still experimental and not ready for everyday use.

You can find more details (including deprecations and removals) in the changelog.

As with all pip releases, a significant amount of the work was contributed by pip’s user community. Huge thanks to all who have contributed, whether through code, documentation, issue reports and/or discussion. Your help keeps pip improving, and is hugely appreciated. Specific thanks go to Mozilla (through its Mozilla Open Source Support Awards) and to the Chan Zuckerberg Initiative DAF, an advised fund of Silicon Valley Community Foundation, for their funding that enabled substantial work on the new resolver.


Tuesday, July 21, 2020

Python 3.8.5 released as a security hotfix. 3.9.0b5, the last beta before 3.9.0, also available


This is a combined release of Python 3.8.5 and 3.9.0b5. Both are significant but for different reasons. Let’s dig in!
 

Security content in 3.8.5

We decided to release 3.8.5 ahead of schedule due to a number of security-related fixes. All details can be found in the change log but the gist is:
  • CVE-2019-20907: infinite loop in a maliciously created .tar file
  • BPO-41288: segmentation fault during unpickling of objects using a crafted NEWOBJ_EX opcode
  • BPO-39603: HTTP headers could be injected through a maliciously crafted method parameter in http.client
  • the original fix for CVE-2020-15801 caused a regression in 3.8.4 (see: BPO-41304)
A small number of other urgent regression fixes and quality-of-life improvements are also present in the release. Get the release here:

https://www.python.org/downloads/release/python-385/

Maintenance releases for the 3.8 series will continue at the regular bi-monthly calendar, with 3.8.6 planned for mid-September 2020.

The last beta of Python 3.9.0 now also available

Python 3.9 is still in development. This release, 3.9.0b5, is the last of five planned beta release previews. 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. You can get 3.9.0b5 here:

https://www.python.org/downloads/release/python-390b5/

The next pre-release, the first release candidate of Python 3.9.0, will be 3.9.0rc1. It is currently scheduled for 2020-08-10.

Call to action

We strongly encourage maintainers of third-party Python projects to test with 3.9 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 (2020-08-10). Our goal is have no ABI changes after beta 5 and as few code changes as possible after 3.9.0rc1, the first release candidate. To achieve that, it will be extremely important to get as much exposure for 3.9 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.

A reminder for core developers

To help make Python 3.9.0 the best possible release, our Development Cycle section of the Python Developer’s Guide documents that:
A branch preparing for an RC release can only have bugfixes applied that have been reviewed by other core developers. Generally, these issues must be severe enough (e.g. crashes) that they deserve fixing before the final release. All other issues should be deferred to the next development cycle, since stability is the strongest concern at this point.
You cannot skip the peer review during an RC, no matter how small! Even if it is a simple copy-and-paste change, everything requires peer review from a core developer.
 

Major new features of the 3.9 series, compared to 3.8

Some of the new major new features and changes in Python 3.9 are:
  • PEP 584, Union Operators in dict
  • PEP 585, Type Hinting Generics In Standard Collections
  • PEP 593, Flexible function and variable annotations
  • PEP 602, Python adopts a stable annual release cadence
  • PEP 615, Support for the IANA Time Zone Database in the Standard Library
  • PEP 616, String methods to remove prefixes and suffixes
  • PEP 617, New PEG parser for CPython
  • BPO 38379, garbage collection does not block on resurrected objects;
  • BPO 38692, os.pidfd_open added that allows process management without races and signals;
  • BPO 39926, Unicode support updated to version 13.0.0;
  • BPO 1635741, when Python is initialized multiple times in the same process, it does not leak memory anymore;
  • A number of Python builtins (range, tuple, set, frozenset, list, dict) are now sped up using PEP 590 vectorcall;
  • A number of Python modules (_abc, audioop, _bz2, _codecs, _contextvars, _crypt, _functools, _json, _locale, operator, resource, time, _weakref) now use multiphase initialization as defined by PEP 489;
  • A number of standard library modules (audioop, ast, grp, _hashlib, pwd, _posixsubprocess, random, select, struct, termios, zlib) are now using the stable ABI defined by PEP 384.
  • (Hey, fellow core developer, if a feature you find important is missing from this list, let Łukasz know.)

We hope you enjoy the new releases!

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

Your friendly release team,
Ned Deily @nad
Steve Dower @steve.dower
Łukasz Langa @ambv

Monday, July 13, 2020

Python 3.8.4 is now available

Python 3.8.4 is the fourth maintenance release of Python 3.8. Go get it here:

https://www.python.org/downloads/release/python-384/

Maintenance releases for the 3.8 series will continue at regular bi-monthly intervals, with 3.8.5 planned for mid-September 2020.

What’s new?

The Python 3.8 series is the newest feature release of the Python language, and it contains many new features and optimizations. See the “What’s New in Python 3.8” document for more information about features included in the 3.8 series.

This is the first bugfix release that is considerably smaller than the previous three. There’s almost 20% fewer changes at 162 commits than the average of previous three bugfix releases. Detailed information about all changes made in version 3.8.4 specifically can be found in its change log. Note that compared to 3.8.3, version 3.8.4 also contains the changes introduced in 3.8.4rc1.

We hope you enjoy Python 3.8!

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


Your friendly release team,
Ned Deily @nad
Steve Dower @steve.dower
Łukasz Langa @ambv

Friday, July 3, 2020

Python 3.9.0b4 is now ready for testing

On behalf of the entire Python development community, and the currently serving Python release team in particular, I’m pleased to announce the release of Python 3.9.0b4. Get it here:

https://www.python.org/downloads/release/python-390b4/

This is a beta preview of Python 3.9

Python 3.9 is still in development. This release, 3.9.0b4, is the fourth of five planned beta release previews.

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.

Call to action

We strongly encourage maintainers of third-party Python projects to test with 3.9 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 (2020-08-10). Our goal is have no ABI changes after beta 5 and as few code changes as possible after 3.9.0rc1, the first release candidate. To achieve that, it will be extremely important to get as much exposure for 3.9 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 3.9 series, compared to 3.8

Some of the new major new features and changes in Python 3.9 are:
  • PEP 584, Union Operators in dict
  • PEP 585, Type Hinting Generics In Standard Collections
  • PEP 593, Flexible function and variable annotations
  • PEP 602, Python adopts a stable annual release cadence
  • PEP 615, Support for the IANA Time Zone Database in the Standard Library
  • PEP 616, String methods to remove prefixes and suffixes
  • PEP 617, New PEG parser for CPython
  • BPO 38379, garbage collection does not block on resurrected objects;
  • BPO 38692, os.pidfd_open added that allows process management without races and signals;
  • BPO 39926, Unicode support updated to version 13.0.0;
  • BPO 1635741, when Python is initialized multiple times in the same process, it does not leak memory anymore;
  • A number of Python builtins (range, tuple, set, frozenset, list, dict) are now sped up using PEP 590 vectorcall;
  • A number of Python modules (_abc, audioop, _bz2, _codecs, _contextvars, _crypt, _functools, _json, _locale, operator, resource, time, _weakref) now use multiphase initialization as defined by PEP 489;
  • A number of standard library modules (audioop, ast, grp, _hashlib, pwd, _posixsubprocess, random, select, struct, termios, zlib) are now using the stable ABI defined by PEP 384.
  • (Hey, fellow core developer, if a feature you find important is missing from this list, let Łukasz know.)
The next pre-release, the fifth beta release of Python 3.9, will be 3.9.0b5. It is currently scheduled for 2020-07-20.

More resources


Your friendly release team,
Ned Deily @nad
Steve Dower @steve.dower
Łukasz Langa @ambv

Tuesday, June 30, 2020

Python 3.8.4rc1 is now ready for testing

Python 3.8.4rc1 is the release candidate of the fourth maintenance release of Python 3.8. Go get it here:
https://www.python.org/downloads/release/python-384rc1/

Assuming no critical problems are found prior to 2020-07-13, the scheduled release date for 3.8.4, no code changes are planned between this release candidate and the final release.
That being said, please keep in mind that this is a pre-release and as such its main purpose is testing.
Maintenance releases for the 3.8 series will continue at regular bi-monthly intervals, with 3.8.5 planned for mid-September 2020.

What’s new?

The Python 3.8 series is the newest feature release of the Python language, and it contains many new features and optimizations. See the “What’s New in Python 3.8” document for more information about features included in the 3.8 series.

This is the first bugfix release that is considerably smaller than the previous three. There’s 20% less changes at 130 commits than the average of previous three releases. Detailed information about all changes made in version 3.8.4 specifically can be found in its change log.

We hope you enjoy Python 3.8!

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


Your friendly release team,
Ned Deily @nad
Steve Dower @steve.dower
Łukasz Langa @ambv

Sunday, June 28, 2020

Python 3.7.8 and 3.6.11 now available - last 3.7.x bugfix release

Python 3.7.8, the next bugfix release of Python 3.7, is now available. You can find the release files, a link to the changelog, and more information here:
    https://www.python.org/downloads/release/python-378/
   
Note that Python 3.8 is now the latest feature release series of Python 3. After two years of quarterly 3.7.x bugfix releases and with the successful release and adoption of Python 3.8 over the last year, 3.7.8 is expected to be the last bugfix release in the 3.7 series. You should consider upgrading to 3.8 as soon as practical. Get the latest release of 3.8.x here.

Following our release support policy, after 3.7.8 we plan to provide security fixes for 3.7 as needed until mid-year 2023, five years after its initial release. More details are available in PEP 537, the Python 3.7 Release Schedule.

In addition to 3.7.8, the lastest security fix rollup for Python 3.6, 3.6.11, is also now available.  You can download its source release here:
    https://www.python.org/downloads/release/python-3611/

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.

Wednesday, June 17, 2020

Python 3.7.8rc1 and 3.6.11rc1 now available for testing

Python 3.7.8rc1 and 3.6.11rc1 are now available. 3.7.8rc1 is the release preview of the next bugfix release of Python 3.7;  3.6.11rc1 is the release preview of the next security-fix release of Python 3.6. Assuming no critical problems are found prior to 2020-06-27, no code changes are planned between these release candidates and the final releases. These release candidates are intended to give you the opportunity to test the new security and bug fixes in 3.7.8 and security fixes in 3.6.11. While we strive to not introduce any incompatibilities in new bugfix and security releases, we encourage you to test your projects and report issues found to bugs.python.org as soon as possible. Please keep in mind that these are preview releases and, thus, their use is not recommended for production environments.

You can find the release files, a link to their changelogs, and more information here:

Sunday, June 14, 2020

Python 3.9.0b3 is now available for testing


On behalf of the entire Python development community, and the currently serving Python release team in particular, I’m pleased to announce the release of Python 3.9.0b3. Get it here:

https://www.python.org/downloads/release/python-390b3/


Wait, Beta 3? What happened to Beta 2?

Beta 2? Speak of him no more. We disappeared him. He was a bad release. Truly awful. I get shivers just thinking about it. Never mention that name again in this house.
I mean, long story short, in Beta 2 you couldn’t do urllib.request.urlopen("https://www.python.org").read() because it wouldn’t find root certificates due to a bug. Since this was a problem only apparent on an installed Python, it wasn’t identified by unit tests and was only found by Ned while he was testing his Mac installer. By the time we learned of the severity of the bug I already tagged and published the release on python.org. That’s why we couldn’t just re-do the release under the same version.
Sorry for the trouble. We’re tweaking our release process to catch this problem sooner in future releases. Now, back to regular programming…

This is a beta preview of Python 3.9

Python 3.9 is still in development. This release, 3.9.0b3, is the third of five planned beta release previews.
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.

Call to action

We strongly encourage maintainers of third-party Python projects to test with 3.9 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 (2020-08-10). Our goal is have no ABI changes after beta 5 and as few code changes as possible after 3.9.0rc1, the first release candidate. To achieve that, it will be extremely important to get as much exposure for 3.9 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 3.9 series, compared to 3.8

Some of the new major new features and changes in Python 3.9 are:
  • PEP 584, Union Operators in dict
  • PEP 585, Type Hinting Generics In Standard Collections
  • PEP 593, Flexible function and variable annotations
  • PEP 602, Python adopts a stable annual release cadence
  • PEP 615, Support for the IANA Time Zone Database in the Standard Library
  • PEP 616, String methods to remove prefixes and suffixes
  • PEP 617, New PEG parser for CPython
  • BPO 38379, garbage collection does not block on resurrected objects;
  • BPO 38692, os.pidfd_open added that allows process management without races and signals;
  • BPO 39926, Unicode support updated to version 13.0.0;
  • BPO 1635741, when Python is initialized multiple times in the same process, it does not leak memory anymore;
  • A number of Python builtins (range, tuple, set, frozenset, list, dict) are now sped up using PEP 590 vectorcall;
  • A number of Python modules (_abc, audioop, _bz2, _codecs, _contextvars, _crypt, _functools, _json, _locale, operator, resource, time, _weakref) now use multiphase initialization as defined by PEP 489;
  • A number of standard library modules (audioop, ast, grp, _hashlib, pwd, _posixsubprocess, random, select, struct, termios, zlib) are now using the stable ABI defined by PEP 384.
  • (Hey, fellow core developer, if a feature you find important is missing from this list, let Łukasz know.)
The next pre-release, the fourth beta release of Python 3.9, will be 3.9.0b4. It is currently scheduled for 2020-06-29.

More resources

Your friendly release team,
   Ned Deily @nad
   Steve Dower @steve.dower
   Łukasz Langa @ambv

Tuesday, May 19, 2020

Python 3.9.0b1 is now available for testing

On behalf of the entire Python development community, and the currently serving Python release team in particular, I’m pleased to announce the release of Python 3.9.0b1. Get it here:

https://www.python.org/downloads/release/python-390b1/


This is a beta preview of Python 3.9

Python 3.9 is still in development. This release, 3.9.0b1, is the first of four planned beta release previews.
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.

Call to action

We strongly encourage maintainers of third-party Python projects to test with 3.9 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 (2020-08-10). Our goal is have no ABI changes after beta 4 and as few code changes as possible after 3.9.0rc1, the first release candidate. To achieve that, it will be extremely important to get as much exposure for 3.9 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 3.9 series, compared to 3.8

Some of the new major new features and changes in Python 3.9 are:
  • PEP 584, Union Operators in dict
  • PEP 585, Type Hinting Generics In Standard Collections
  • PEP 593, Flexible function and variable annotations
  • PEP 602, Python adopts a stable annual release cadence
  • PEP 616, String methods to remove prefixes and suffixes
  • PEP 617, New PEG parser for CPython
  • BPO 38379, garbage collection does not block on resurrected objects;
  • BPO 38692, os.pidfd_open added that allows process management without races and signals;
  • BPO 39926, Unicode support updated to version 13.0.0;
  • BPO 1635741, when Python is initialized multiple times in the same process, it does not leak memory anymore;
  • A number of Python builtins (range, tuple, set, frozenset, list, dict) are now sped up using PEP 590 vectorcall;
  • A number of Python modules (_abc, audioop, _bz2, _codecs, _contextvars, _crypt, _functools, _json, _locale, operator, resource, time, _weakref) now use multiphase initialization as defined by PEP 489;
  • A number of standard library modules (audioop, ast, grp, _hashlib, pwd, _posixsubprocess, random, select, struct, termios, zlib) are now using the stable ABI defined by PEP 384.
  • (Hey, fellow core developer, if a feature you find important is missing from this list, let Łukasz know.)
The next pre-release, the second beta release of Python 3.9, will be 3.9.0b2. It is currently scheduled for 2020-06-08.

More resources

Your friendly release team,
Ned Deily @nad
Steve Dower @steve.dower
Łukasz Langa @ambv

Thursday, May 14, 2020

Python 3.8.3 is now available

On behalf of the entire Python development community, and the currently serving Python release team in particular, I’m pleased to announce the release of Python 3.8.3, the third maintenance release of Python 3.8. You can find it here:


It contains two months worth of bug fixes. Detailed information about all changes made in 3.8.3 can be found in its change log. Note that compared to 3.8.2, version 3.8.3 also contains the changes introduced in 3.8.3rc1.

The Python 3.8 series is the newest feature release of the Python language, and it contains many new features and optimizations. See the “What’s New in Python 3.8” document for more information about features included in the 3.8 series.

Maintenance releases for the 3.8 series will continue at regular bi-monthly intervals, with 3.8.4 planned for mid-July 2020.

One more thing

Unless blocked on any critical issue, Monday May 18th will be the release date of Python 3.9.0 beta 1. It’s a special release because this is when we lock the feature set for Python 3.9. If you can help testing the current available alpha release, that would be very helpful:

We hope you enjoy the new Python release!

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


Your friendly release team,
Ned Deily @nad
Steve Dower @steve.dower
Łukasz Langa @ambv

Thursday, April 30, 2020

Pip 20.1 has been released

On behalf of the PyPA, I am pleased to announce that a new version of pip, pip 20.1, has been released.

To install pip 20.1, you can run:
python -m pip install --upgrade pip
The highlights for this release are:
  • Significant speedups when building local directories, by changing behavior to perform in-place builds, instead of copying to temporary directories.
  • Significant speedups in pip list --outdated, by parallelizing network access. This is the first instance of parallel code within pip's codebase.
  • A new pip cache command, which makes it possible to introspect and manage pip's cache directory.
  • Better pip freeze for packages installed from direct URLs, enabled by the implementation of PEP 610.

This release also contains an alpha version of pip's next generation resolver. It is off by default because it is unstable and not ready for everyday use. If you're curious about this, please visit this GitHub issue about the resolver, what doesn't work yet, and what kind of testing would help us out. We plan to release a version of pip that includes a beta of the new resolver in May.

The full changelog is available.

As with all pip releases, a significant amount of the work was contributed by pip's user community. Huge thanks to all who have contributed, whether through code, documentation, issue reports and/or discussion. Your help keeps pip improving, and is hugely appreciated.

Thank you to the pip and PyPA maintainers, and to all the contributors and volunteers who work on or use Python packaging tools.

And thank you to Mozilla (through its Mozilla Open Source Support Awards) and to the Chan Zuckerberg Initiative DAF, an advised fund of Silicon Valley Community Foundation, for funding enabling work on the new resolver, and thanks to the PSF and the Packaging WG for obtaining and administering that funding.

Tuesday, April 28, 2020

Python 3.9.0a6 is now available for testing

On behalf of the entire Python development community, and the currently serving Python release team in particular, I’m pleased to announce the release of Python 3.9.0a6. Get it here:

https://www.python.org/downloads/release/python-390a6/

 

This is an early developer preview of Python 3.9

Python 3.9 is still in development. This release, 3.9.0a6, is the last out of six 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 (2020-05-18) and, if necessary, may be modified or deleted up until the release candidate phase (2020-08-10). Please keep in mind that this is a preview release and its use is not recommended for production environments.

 

Major new features of the 3.9 series, compared to 3.8

Many new features for Python 3.9 are still being planned and written. Among the new major new features and changes so far:
  • PEP 584, Union Operators in dict
  • PEP 585, Type Hinting Generics In Standard Collections
  • PEP 593, Flexible function and variable annotations
  • PEP 602, Python adopts a stable annual release cadence
  • PEP 616, String methods to remove prefixes and suffixes
  • PEP 617, New PEG parser for CPython
  • BPO 38379, garbage collection does not block on resurrected objects;
  • BPO 38692, os.pidfd_open added that allows process management without races and signals;
  • BPO 39926, Unicode support updated to version 13.0.0
  • BPO 1635741, when Python is initialized multiple times in the same process, it does not leak memory anymore
  • A number of Python builtins (range, tuple, set, frozenset, list) are now sped up using PEP 590 vectorcall
  • A number of standard library modules (audioop, ast, grp, _hashlib, pwd, _posixsubprocess, random, select, struct, termios, zlib) are now using the stable ABI defined by PEP 384.
  • (Hey, fellow core developer, if a feature you find important is missing from this list, let Łukasz know.)
The next pre-release, the first beta release of Python 3.9, will be 3.9.0b1. It is currently scheduled for 2020-05-18.

Your friendly release team,
Ned Deily @nad
Steve Dower @steve.dower
Łukasz Langa @ambv

Monday, April 20, 2020

Python 2.7.18, the last release of Python 2

The CPython core developers are pleased to announce the immediate availability of Python 2.7.18.

Python 2.7.18 is the last Python 2.7 release and therefore the last Python 2 release. It's time for the CPython community to say a fond but firm farewell to Python 2.

Download this unique, commemorative Python release on python.org.

Python 2.7 has been under active development since the release of Python 2.6, more than 11 years ago. Over all those years, CPython's core developers and contributors sedulously applied bug fixes to the 2.7 branch, no small task as the Python 2 and 3 branches diverged. There were large changes midway through Python 2.7's life such as PEP 466's feature backports to the ssl module and hash randomization. Traditionally, these features would never have been added to a branch in maintenance mode, but exceptions were made to keep Python 2 users secure. Thank you to CPython's community for such dedication.

Python 2.7 was lucky to have the services of two generations of binary builders and operating system experts, Martin von Löwis and Steve Dower for Windows, and Ronald Oussoren and Ned Deily for macOS. The reason we provided binary Python 2.7 releases for macOS 10.9, an operating system obsoleted by Apple 4 years ago, or why the "Microsoft Visual C++ Compiler for Python 2.7" exists is the dedication of these individuals.

Python 3 would be nowhere without the dedication of the wider community. Library maintainers followed CPython by maintaining Python 2 support for many years but also threw their weight behind the Python 3 statement. Linux distributors chased Python 2 out of their archives. Users migrated hundreds of millions of lines of code, developed porting guides, and kept Python 2 in their brain while Python 3 gained 10 years of improvements.

Finally, thank you to GvR for creating Python 0.9, 1, 2, and 3.

Long live Python 3+!

Monday, April 6, 2020

Python 2.7.18 release candidate 1 available

A first release candidate for Python 2.7.18 is now available for download. Python 2.7.18 will be the last release of the Python 2.7 series, and thus Python 2.

Monday, March 23, 2020

Python 3.9.0a5 is now available for testing

On behalf of the entire Python development community, and the currently serving Python release team in particular, I’m pleased to announce the release of Python 3.9.0a5. Get it here:


This is an early developer preview of Python 3.9


Python 3.9 is still in development. This releasee, 3.9.0a5 is the fifth of six 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 (2020-05-18) and, if necessary, may be modified or deleted up until the release candidate phase (2020-08-10). Please keep in mind that this is a preview release and its use is not recommended for production environments.


Major new features of the 3.9 series, compared to 3.8


Many new features for Python 3.9 are still being planned and written. Among the new major new features and changes so far:
  • PEP 584, Union Operators in dict
  • PEP 593, Flexible function and variable annotations
  • PEP 602, Python adopts a stable annual release cadence
  • BPO 38379, garbage collection does not block on resurrected objects;
  • BPO 38692, os.pidfd_open added that allows process management without races and signals;
  • BPO 39926, Unicode support updated to version 13.0.0
  • BPO 1635741, when Python is initialized multiple times in the same process, it does not leak memory anymore
  • A number of Python builtins (range, tuple, set, frozenset, list) are now sped up using PEP 590 vectorcall
  • A number of standard library modules (audioop, ast, grp, _hashlib, pwd, _posixsubprocess, random, select, struct, termios, zlib) are now using the stable ABI defined by PEP 384.
  • (Hey, fellow core developer, if a feature you find important is missing from this list, let Łukasz know.)
The next pre-release, the last alpha release of Python 3.9, will be 3.9.0a6. It is currently scheduled for 2020-04-22. Until then, stay safe!

Tuesday, March 10, 2020

Python 3.7.7 is now available

Python 3.7.7, the next bugfix release of Python 3.7, is now available. You can find the release files, a link to the changelog, and more information here:
    https://www.python.org/downloads/release/python-377/
   
Note that Python 3.8 is now the latest feature release series of Python 3. You should consider upgrading to it. Get the latest release of 3.8.x here. We plan to continue regular bugfix releases of Python 3.7.x through mid-year 2020 and provide security fixes for it until mid-year 2023.  More details are available in PEP 537, the Python 3.7 Release Schedule.

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.

Wednesday, March 4, 2020

Python 3.7.7rc1 is now available for testing

Python 3.7.7rc1, the release preview of the next maintenance release of Python 3.7, is now available for testing. Assuming no critical problems are found prior to 2020-02-10, no code changes are planned between this release candidate and the final release. The release candidate is intended to give you the opportunity to test the new security and bug fixes in 3.7.7. While we strive to not introduce any incompatibilities in new maintenance releases, we encourage you to test your projects and report issues found to bugs.python.org as soon as possible. Please keep in mind that, since this is a preview release, its use is not recommended for production environments.

You can find the release files, a link to the changelog, and more information here:

Tuesday, February 25, 2020

Python 3.8.2 and 3.9.0a4 are now available

On behalf of the entire Python development community, and the currently serving Python release team in particular, I’m pleased to announce the release of two of the latest Python editions.

Python 3.8.2

Python 3.8.2 is the second maintenance release of Python 3.8 and contains two months worth of bug fixes. Detailed information about all changes made in 3.8.2 can be found in its change log. Note that compared to 3.8.1, version 3.8.2 also contains the changes introduced in 3.8.2rc1 and 3.8.2rc2.

The Python 3.8 series is the newest feature release of the Python language, and it contains many new features and optimizations. You can find Python 3.8.2 here:
https://www.python.org/downloads/release/python-382/

See the What’s New in Python 3.8document for more information about features included in the 3.8 series.

Maintenance releases for the 3.8 series will continue at regular bi-monthly intervals, with 3.8.3 planned for April 2020 (at the PyCon US sprints).

Python 3.9.0a4

An early developer preview of Python 3.9 is also ready:
https://www.python.org/downloads/release/python-390a4/

Python 3.9 is still in development. This releasee, 3.9.0a4 is the fourth of six 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 (2020-05-18) and, if necessary, may be modified or deleted up until the release candidate phase (2020-08-10). Please keep in mind that this is a preview release and its use is not recommended for production environments.

We hope you enjoy both!

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.
https://www.python.org/psf/

Your friendly release team,

Ned Deily
Steve Dower
Łukasz Langa

Tuesday, February 18, 2020

Python 3.8.2rc2 is now available for testing

Python 3.8.2rc2 is the second release candidate of the second maintenance release of Python 3.8. Go get it here:

https://www.python.org/downloads/release/python-382rc2/

Why a second release candidate?

The major reason for RC2 is that GH-16839 has been reverted.

The original change was supposed to fix for some edge cases in urlparse (numeric paths, recognizing netlocs without //; details in BPO-27657). Unfortunately it broke third parties relying on the pre-existing undefined behavior.

Sadly, the reverted fix has already been released as part of 3.8.1 (and 3.7.6 where it’s also reverted now). As such, even though the revert is itself a bug fix, it is incompatible with the behavior of 3.8.1.

Please test.

Timeline

Assuming no critical problems are found prior to 2020-02-24, the currently scheduled release date for  3.8.2 (as well as 3.9.0 alpha 4!), no code changes are planned between this release candidate and the final release.

That being said, please keep in mind that this is a pre-release of 3.8.2 and as such its main purpose is testing.

Maintenance releases for the 3.8 series will continue at regular bi-monthly intervals, with 3.8.3 planned for April 2020 (during sprints at PyCon US).

What’s new?

The Python 3.8 series is the newest feature release of the Python language, and it contains many new features and optimizations. See the “What’s New in Python 3.8” document for more information about features included in the 3.8 series.

Detailed information about all changes made in version 3.8.2 specifically can be found in its change log.

We hope you enjoy Python 3.8!

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.

Saturday, January 25, 2020

Python 3.9.0a3 now available for testing

Go get it here: https://www.python.org/downloads/release/python-390a3/

This is an early developer preview of Python 3.9

Python 3.9 is still in development. This releasee, 3.9.0a3 is the third of six 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 (2020-05-18) and, if necessary, may be modified or deleted up until the release candidate phase (2020-08-10). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Major new features of the 3.9 series, compared to 3.8

Many new features for Python 3.9 are still being planned and written. Among the new major new features and changes so far:
  • PEP 602, Python adopts a stable annual release cadence
  • BPO 38379, garbage collection does not block on resurrected objects;
  • BPO 38692, os.pidfd_open added that allows process management without races and signals;
  • A number of standard library modules (audioop, ast, grp, _hashlib, pwd, _posixsubprocess, random, select, struct, termios, zlib) are now using the stable ABI defined by PEP 384.
  • (Hey, fellow core developer, if a feature you find important is missing from this list, let Łukasz know.)

The next pre-release of Python 3.9 will be 3.9.0a4, currently scheduled for 2020-02-17.