Python Insider

Python 3.11.0a1 is available

2021-10-07T08:03:00.006-04:00

Now that we are on a release spree, here you have the first alpha release of Python 3.11: Python 3.11.0a1. Let the testing and validation games begin!

https://www.python.org/downloads/release/python-3110a1/

Major new features of the 3.11 series, compared to 3.10

Among the new major new features and changes so far:

PEP 657 – Include Fine-Grained Error Locations in Tracebacks
PEP 654 – PEP 654 – Exception Groups and except*
(Hey, fellow core developer, if a feature you find important is missing from this list, let Pablo know.)

The next pre-release of Python 3.11 will be 3.11.0a2, currently scheduled for 2021-11-02.

More resources

Online Documentation

PEP 664, 3.11 Release Schedule
Report bugs at https://bugs.python.org.

Help fund Python and its community.

And now for something completely different

Schwarzschild black holes are also unique because they have a space-like singularity at their core, which means that the singularity doesn't happen at a specific point in *space* but happens at a specific point in *time* (the future). This means once you are inside the event horizon you cannot point with your finger towards the direction the singularity is located because the singularity happens in your future: no matter where you move, you will "fall" into it.

For a Schwarzschild black hole (a black hole with no rotation or electromagnetic charge), given a free fall particle starting at the event horizon, the maximum propper time (which happens when it falls without angular velocity) it will experience to fall into the singularity is `π*M` (in natural units), where M is the mass of the black hole. For Sagittarius A* (the black hole at the centre of the milky way) this time is approximately 1 minute.

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.

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

Your friendly release team,
Ned Deily @nad
Steve Dower @steve.dower
Pablo Galindo Salgado @pablogsal

Python 3.10.0 is available

2021-10-04T17:07:00.006-04:00

On behalf of the Python development community and the Python 3.10 release team, I’m pleased to announce the availability of Python 3.10.0.

Python 3.10.0 is the newest major release of the Python programming language, and it contains many new features and optimizations.

https://www.python.org/downloads/release/python-3100/

Major new features of the 3.10 series, compared to 3.9

Among the new major new features and changes so far:

PEP 623 – Deprecate and prepare for the removal of the wstr member in PyUnicodeObject.

PEP 604 – Allow writing union types as X | Y

PEP 612 – Parameter Specification Variables

PEP 626 – Precise line numbers for debugging and other tools.

PEP 618 – Add Optional Length-Checking To zip.

bpo-12782: Parenthesized context managers are now officially allowed.

PEP 632 – Deprecate distutils module.

PEP 613 – Explicit Type Aliases

PEP 634 – Structural Pattern Matching: Specification

PEP 635 – Structural Pattern Matching: Motivation and Rationale

PEP 636 – Structural Pattern Matching: Tutorial

PEP 644 – Require OpenSSL 1.1.1 or newer

PEP 624 – Remove Py_UNICODE encoder APIs

PEP 597 – Add optional EncodingWarning

More resources

Online Documentation

PEP 619, 3.10 Release Schedule

Report bugs at https://bugs.python.org.

Help fund Python and its community.

bpo-38605: from __future__ import annotations (PEP 563) used to be on this list in previous pre-releases but it has been postponed to Python 3.11 due to some compatibility concerns. You can read the Steering Council communication about it here to learn more.

And now for something completely different

We hope you enjoy the new releases!

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

Your friendly release team,
Ned Deily @nad
Steve Dower @steve.dower
Pablo Galindo Salgado @pablogsal

Python 3.10.0rc2 is available

2021-09-07T19:33:00.004-04:00

Python 3.10 is one month away, can you believe it? This snake is still trying to bite as it has been an interesting day of fighting fires, release blockers, and a bunch of late bugs but your friendly release team always delivers

You can get this new release while is still fresh here:

https://www.python.org/downloads/release/python-3100rc2/

This release, 3.10.0rc2, is the last preview before the final release of Python 3.10.0 on 2021-10-04. Entering the release candidate phase, only reviewed code changes which are clear bug fixes are allowed between release candidates and the final release. There will be no ABI changes from this point forward in the 3.10 series and the goal is that there will be as few code changes as possible.

Call to action

The 3.10 branch is now accepting changes for 3.10.1. To maximize stability, the final release will be cut from the v3.10.0rc2 tag. If you need the release manager to cherry-pick any critical fixes, mark issues as release blockers and/or add him as a reviewer on a critical backport PR on GitHub.

To see which changes are currently cherry-picked for inclusion in 3.10.0, look at the short-lived branch-v3.10.0 https://github.com/python/cpython/tree/branch-v3.10.0 on GitHub.

Core developers: all eyes on the docs now

Are all your changes properly documented?

Did you notice other changes you know of to have insufficient documentation?

Community members

We strongly encourage maintainers of third-party Python projects to prepare their projects for 3.10 compatibilities during this phase. As always, report any issues to the Python bug tracker.

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

Major new features of the 3.10 series, compared to 3.9

Many new features for Python 3.10 are still being planned and written. Among the new major new features and changes so far:

PEP 623 – Deprecate and prepare for the removal of the wstr member in PyUnicodeObject.
PEP 604 – Allow writing union types as X | Y
PEP 612 – Parameter Specification Variables
PEP 626 – Precise line numbers for debugging and other tools.
PEP 618 – Add Optional Length-Checking To zip.
bpo-12782: Parenthesized context managers are now officially allowed.
PEP 632 – Deprecate distutils module.
PEP 613 – Explicit Type Aliases
PEP 634 – Structural Pattern Matching: Specification
PEP 635 – Structural Pattern Matching: Motivation and Rationale
PEP 636 – Structural Pattern Matching: Tutorial
PEP 644 – Require OpenSSL 1.1.1 or newer
PEP 624 – Remove Py_UNICODE encoder APIs
PEP 597 – Add optional EncodingWarning
(Hey, fellow core developer, if a feature you find important is missing from this list, let Pablo know.)

The next release will be the final release of Python 3.10.0, which is currently scheduled for Monday, 2021-10-04.

More resources

And now for something completely different

Maxwell’s demon is a thought experiment that would hypothetically violate the second law of thermodynamics. It was proposed by the physicist James Clerk Maxwell in 1867. In the thought experiment, a demon controls a small massless door between two chambers of gas. As individual gas molecules (or atoms) approach the door, the demon quickly opens and closes the door to allow only fast-moving molecules to pass through in one direction, and only slow-moving molecules to pass through in the other. Because the kinetic temperature of a gas depends on the velocities of its constituent molecules, the demon’s actions cause one chamber to warm up and the other to cool down. This would decrease the total entropy of the two gases, without applying any work, thereby violating the second law of thermodynamics.

We hope you enjoy those new releases!

Your friendly release team,

Pablo Galindo @pablogsal

Ned Deily @nad

Steve Dower @steve.dower

Python 3.7.12 and 3.6.15 security updates now available

2021-09-04T18:00:00.001-04:00

Python 3.7.12 and 3.6.15, the lastest security fix rollups for Python 3.7 and Python 3.6, are now available. You can find the release files, links to the changelogs, and more information here:

https://www.python.org/downloads/release/python-3712/
https://www.python.org/downloads/release/python-3615/

These releases are source code only; Windows and macOS binary installers are not provided for security fix releases.

Note that Python 3.9 is now the latest feature release series of Python 3. You should consider upgrading to 3.9 as soon as practical. Get the latest release of 3.9.x here.

Python 3.9.7 and 3.8.12 are now available

2021-08-30T18:32:00.000-04:00

Python 3.9.7

Python 3.9.7 is the newest major stable release of the Python programming language, and it contains many new features and optimizations. There’s been 187 commits since 3.9.6 which is a similar amount compared to 3.8 at the same stage of the release cycle. See the change log for details.

On macOS, we encourage you to use the universal2 binary installer variant whenever possible. The legacy 10.9+ Intel-only variant will not be provided for Python 3.10 and the universal2 variant will become the default download for 3.9.8. You may need to upgrade third-party components, like pip, to later versions. You may experience differences in behavior in IDLE and other Tk-based applications due to using the newer version of Tk. As always, if you encounter problems when using this installer variant, please check https://bugs.python.org for existing reports and for opening new issues.

The next Python 3.9 maintenance release will be 3.9.8, currently scheduled for 2021-11-01.

The Second Security-Only Release of Python 3.8

Security content in this release contains four fixes. There are also four additional fixes for bugs that might have lead to denial-of-service attacks. Finally, while we’re not providing binary installers anymore, for those users who produce installers, we upgraded the OpenSSL version used to 1.1.1l. Take a look at the change log for details.

According to the release calendar specified in PEP 569, Python 3.8 is now in “security fixes only” stage of its life cycle: 3.8 branch only accepts security fixes and releases of those are made irregularly in source-only form until October 2024. Python 3.8 isn’t receiving regular bug fixes anymore, and binary installers are no longer provided for it. Python 3.8.10 was the last full bugfix release of Python 3.8 with binary installers.

Security releases of 3.7.12 and 3.6.15

Those aren’t ready just yet but are soon to follow.

Similarly to 3.8, Python 3.7 and 3.6 are now in “security fixes only” stage of their life cycle. Python 3.7 will be providing source archives until June 2023 while Python 3.6 ends its life in December 2021.

We hope you enjoy the new releases

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

Python 3.10.0rc1 is available

2021-08-03T12:34:00.002-04:00

Python 3.10.0 is almost ready. This release, 3.10.0rc1, is the penultimate release preview. You can get it here:

https://www.python.org/downloads/release/python-3100rc1/

This release, **3.10.0rc1**, 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

currently planned for 2021-09-06 while the official release is planned for 2021-10-04.

There will be no ABI changes from this point forward in the 3.10 series and the goal is that there will be as few code changes as possible.

Call to action

Core developers: all eyes on the docs now

Are all your changes properly documented?
Did you notice other changes you know of to have insufficient documentation?

Community members

We strongly encourage maintainers of third-party Python projects to prepare their projects for 3.10 compatibilities during this phase. As always, report any issues to the Python bug tracker.

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

Major new features of the 3.10 series, compared to 3.9

Many new features for Python 3.10 are still being planned and written. Among the new major new features and changes so far:

PEP 623 – Deprecate and prepare for the removal of the wstr member in PyUnicodeObject.
PEP 604 – Allow writing union types as X | Y
PEP 612 – Parameter Specification Variables
PEP 626 – Precise line numbers for debugging and other tools.
PEP 618 – Add Optional Length-Checking To zip.
bpo-12782: Parenthesized context managers are now officially allowed.
PEP 632 – Deprecate distutils module.
PEP 613 – Explicit Type Aliases
PEP 634 – Structural Pattern Matching: Specification
PEP 635 – Structural Pattern Matching: Motivation and Rationale
PEP 636 – Structural Pattern Matching: Tutorial
PEP 644 – Require OpenSSL 1.1.1 or newer
PEP 624 – Remove Py_UNICODE encoder APIs
PEP 597 – Add optional EncodingWarning
(Hey, fellow core developer, if a feature you find important is missing from this list, let Pablo know.)

The next pre-release, the second release candidate, will only be released if needed (scheduled for Monday, 2021-09-06). Otherwise, the next release will directly be the final release of Python 3.10.0, which is currently scheduled for Monday, 2021-10-04.

More resources

And now for something completely different

In quantum physics, the spin is an intrinsic form of angular momentum carried by elementary particles, composite particles, and atomic nuclei. The spin is one of two types of angular momentum in quantum mechanics, the other being orbital angular momentum. The orbital angular momentum operator is the quantum-mechanical counterpart to the classical angular momentum of orbital revolution and appears when there is periodic structure to its wavefunction as the angle varies. For photons, spin is the quantum-mechanical counterpart of the polarization of light; for electrons, the spin has no classical counterpart.

We hope you enjoy those new releases!

Your friendly release team,

Pablo Galindo @pablogsal

Ned Deily @nad

Steve Dower @steve.dower

Python 3.10.0b4 is available

2021-07-10T21:48:00.005-04:00

Wow! A release on a Saturday? Do the release management team even rest? You better believe it, because this is the last of the planned beta releases. This means that the next pre-release will be the first release candidate of Python 3.10.0. Remember that our goal is to have no ABI changes after this beta and a few code changes as possible after 3.10.0rc1.

The final release is closer and closer.... just a few more months!

https://www.python.org/downloads/release/python-3100b4/

This is a beta preview of Python 3.10

Python 3.10 is still in development. 3.10.0b4 is the fourth and last of the 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.

We **strongly encourage** maintainers of third-party Python projects to **test with 3.10** during the beta phase and report issues found to [the Python bug tracker](https://bugs.python.org/) 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 (Monday, 2021-08-02). Our goal is to have no ABI changes after beta 4 and as few code changes as possible after 3.10.0rc1, the first release candidate. To achieve that, it will be **extremely important** to get as much exposure for 3.10 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 3.10 series, compared to 3.9

Many new features for Python 3.10 are still being planned and written. Among the new major new features and changes so far:

PEP 623 – Deprecate and prepare for the removal of the wstr member in PyUnicodeObject.
PEP 604 – Allow writing union types as X | Y
PEP 612 – Parameter Specification Variables
PEP 626 – Precise line numbers for debugging and other tools.
PEP 618 – Add Optional Length-Checking To zip.
bpo-12782: Parenthesized context managers are now officially allowed.
PEP 632 – Deprecate distutils module.
PEP 613 – Explicit Type Aliases
PEP 634 – Structural Pattern Matching: Specification
PEP 635 – Structural Pattern Matching: Motivation and Rationale
PEP 636 – Structural Pattern Matching: Tutorial
PEP 644 – Require OpenSSL 1.1.1 or newer
PEP 624 – Remove Py_UNICODE encoder APIs
PEP 597 – Add optional EncodingWarning
(Hey, fellow core developer, if a feature you find important is missing from this list, let Pablo know.)

The next pre-release, the first release candidate of Python 3.10.0, will be 3.10.0rc1. It is currently scheduled for Monday, 2021-08-02.

More resources

And now for something completely different

We hope you enjoy those new releases!

Your friendly release team,

Pablo Galindo @pablogsal

Ned Deily @nad

Steve Dower @steve.dower

Python 3.9.6, 3.8.11, 3.7.11, and 3.6.14 are now available

2021-06-28T15:10:00.001-04:00

Python 3.9.6

Get it here: https://www.python.org/downloads/release/python-396/

Python 3.9.6 is the newest major stable release of the Python programming language, and it contains many new features and optimizations. There’s been 146 commits since 3.9.5 which is a similar amount compared to 3.8 at the same stage of the release cycle. See the change log for details.

On macOS, we encourage you to use the universal2 binary installer variant whenever possible. The legacy 10.9+ Intel-only variant will not be provided for Python 3.10 and the universal2 variant will become the default download for future 3.9.x releases. You may need to upgrade third-party components, like pip, to later versions once they are released. You may experience differences in behavior in IDLE and other Tk-based applications due to using the newer version of Tk. As always, if you encounter problems when using this installer variant, please check https://bugs.python.org for existing reports and for opening new issues.

The next Python 3.9 maintenance release will be 3.9.7, currently scheduled for 2021-08-30.

The First Security-Only Release of Python 3.8

Get it here: https://www.python.org/downloads/release/python-3811/

Security content in this release contains three fixes. There’s also two fixes for 3.8.10 regressions. Take a look at the change log for details.

According to the release calendar specified in PEP 569, Python 3.8 is now in security fixes only stage of its life cycle: 3.8 branch only accepts security fixes and releases of those are made irregularly in source-only form until October 2024. Python 3.8 isn’t receiving regular bugfixes anymore, and binary installers are no longer provided for it. Python 3.8.10 was the last full bugfix release of Python 3.8 with binary installers.

Security releases of 3.7.11 and 3.6.14

Get them here:
https://www.python.org/downloads/release/python-3711/
https://www.python.org/downloads/release/python-3614/

Security content in those releases contains five fixes each. Check out the relevant change logs for 3.7.11 and 3.6.14 for details.

Similarly to 3.8, Python 3.7 and 3.6 are now in security fixes only stage of their life cycle. Python 3.7 will be providing them until June 2023 while Python 3.6 ends its life in December 2021.

We hope you enjoy the new releases

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

Python 3.10.0b3 is available

2021-06-17T17:38:00.000-04:00

Summer is almost here (at least in half of the planet) and Python 3.10 is finishing baking in the oven. For those of you that want to taste it before is finally ready (and if you are a library developer, you certainly do!) you can have the second-to-last beta now, but be careful as is very hot

https://www.python.org/downloads/release/python-3100b3/

This is a beta preview of Python 3.10

Python 3.10 is still in development. 3.10.0b3 is the third 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.

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

Major new features of the 3.10 series, compared to 3.9

Many new features for Python 3.10 are still being planned and written. Among the new major new features and changes so far:

PEP 623 – Deprecate and prepare for the removal of the wstr member in PyUnicodeObject.
PEP 604 – Allow writing union types as X | Y
PEP 612 – Parameter Specification Variables
PEP 626 – Precise line numbers for debugging and other tools.
PEP 618 – Add Optional Length-Checking To zip.
bpo-12782: Parenthesized context managers are now officially allowed.
PEP 632 – Deprecate distutils module.
PEP 613 – Explicit Type Aliases
PEP 634 – Structural Pattern Matching: Specification
PEP 635 – Structural Pattern Matching: Motivation and Rationale
PEP 636 – Structural Pattern Matching: Tutorial
PEP 644 – Require OpenSSL 1.1.1 or newer
PEP 624 – Remove Py_UNICODE encoder APIs
PEP 597 – Add optional EncodingWarning
(Hey, fellow core developer, if a feature you find important is missing from this list, let Pablo know.)

The next pre-release of Python 3.10 will be 3.10.0b4, currently scheduled for Saturday, 2021-07-10.

More resources

And now for something completely different

There are no green stars. Why? In general, objects don't emit a single wavelength of light when they shine. Instead, they emit photons in a range of wavelengths. If you were to use some sort of detector that is sensitive to the wavelengths of light emitted by an object, and then plotted the number of them versus wavelength, you get a lopsided plot called a blackbody curve. For an object as hot as the Sun, that curve peaks at blue-green, so it emits most of its photons there. But it still emits some that are bluer, and some that are redder. When we look at the Sun, we see all these colors blended together. Our eyes mix them up to produce one color: white. A warmer star will put out more blue, and a cooler one redder, but no matter what, our eyes just won't see that as green. Due to how we perceive color, the only way to see a star as being green is for it to be only emitting green light. But as starts always emit radiation following the blackbody curve, that's pretty much impossible.

We hope you enjoy those new releases!

Your friendly release team,

Pablo Galindo @pablogsal

Ned Deily @nad

Steve Dower @steve.dower

Python 3.10.0b2 is available

2021-06-01T07:04:00.002-04:00

After fighting with some release blockers, implementing a bunch of GC traversal functions, and fixing some pending reference leaks, we finally have Python 3.10.0 beta 2 ready for you! Thanks to everyone that helped to unblock the release!

https://www.python.org/downloads/release/python-3100b2/

This is a beta preview of Python 3.10

Python 3.10 is still in development. 3.10.0b2 is the second 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.

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

Major new features of the 3.10 series, compared to 3.9

Many new features for Python 3.10 are still being planned and written. Among the new major new features and changes so far:

PEP 623 – Deprecate and prepare for the removal of the wstr member in PyUnicodeObject.
PEP 604 – Allow writing union types as X | Y
PEP 612 – Parameter Specification Variables
PEP 626 – Precise line numbers for debugging and other tools.
PEP 618 – Add Optional Length-Checking To zip.
bpo-12782: Parenthesized context managers are now officially allowed.
PEP 632 – Deprecate distutils module.
PEP 613 – Explicit Type Aliases
PEP 634 – Structural Pattern Matching: Specification
PEP 635 – Structural Pattern Matching: Motivation and Rationale
PEP 636 – Structural Pattern Matching: Tutorial
PEP 644 – Require OpenSSL 1.1.1 or newer
PEP 624 – Remove Py_UNICODE encoder APIs
PEP 597 – Add optional EncodingWarning
(Hey, fellow core developer, if a feature you find important is missing from this list, let Pablo know.)

The next pre-release of Python 3.10 will be 3.10.0b3, currently scheduled for Thursday, 2021-06-17.

More resources

And now for something completely different

The Ehrenfest paradox concerns the rotation of a "rigid" disc in the theory of relativity. In its original 1909 formulation as presented by Paul Ehrenfest in relation to the concept of Born rigidity within special relativity, it discusses an ideally rigid cylinder that is made to rotate about its axis of symmetry. The radius R as seen in the laboratory frame is always perpendicular to its motion and should therefore be equal to its value R0 when stationary. However, the circumference (2πR) should appear Lorentz-contracted to a smaller value than at rest. This leads to the apparent contradiction that R = R0 and R < R0.

We hope you enjoy those new releases!

Your friendly release team,

Pablo Galindo @pablogsal

Ned Deily @nad

Steve Dower @steve.dower

Python 3.8.10, 3.9.5, and 3.10.0b1 are now available

2021-05-03T19:16:00.002-04:00

This has been a very busy day for releases and on behalf of the Python development community we’re happy to announce the availability of three new Python releases.

Python 3.10 is now in Beta

Get it here: https://www.python.org/downloads/release/python-3100b1/

Python 3.10 is still in development. 3.10.0b1 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.

We strongly encourage maintainers of third-party Python projects to test with 3.10 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 (Monday, 2021-08-02). Our goal is have no ABI changes after beta 4 and as few code changes as possible after 3.10.0rc1, the first release candidate. To achieve that, it will be extremely important to get as much exposure for 3.10 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.

The next pre-release, the second beta release of Python 3.10, will be 3.10.0b2. It is currently scheduled for 2021-05-25. Please see PEP 619 for details.

Development Begins on Python 3.11

With Python 3.10 moving to beta, it received its own 3.10 branch in the repository. All new features are now targeting Python 3.11, to be released in October 2022.

Using the opportunity with the creation of the 3.10 branch, we renamed the master branch of the repository to main. It’s been a bit rocky but looks like we’re open for business. Please rename the main branch of your personal fork using the guide GitHub will give you when you go to your fork’s main page. In case of any outstanding issues, please contact the 3.11 RM.

Python 3.9.5

Get it here: https://www.python.org/downloads/release/python-395/

Python 3.9.5 is the newest major stable release of the Python programming language, and it contains many new features and optimizations. There’s been 111 commits since 3.9.4 which is a similar amount compared to 3.8 at the same stage of the release cycle. See the change log for details.

On macOS, we encourage you to use the universal2 binary installer variant whenever possible. The legacy 10.9+ Intel-only variant will not be provided for Python 3.10 and the universal2 variant will become the default download for future 3.9.x releases. You may need to upgrade third-party components, like pip, to later versions once they are released. You may experience differences in behavior in IDLE and other Tk-based applications due to using the newer version of Tk. As always, if you encounter problems when using this installer variant, please check https://bugs.python.org for existing reports and for opening new issues.

The next Python 3.9 maintenance release will be 3.9.6, currently scheduled for 2021-06-28.

The Last Regular Bugfix Release of Python 3.8

Get it here: https://www.python.org/downloads/release/python-3810/

According to the release calendar specified in PEP 569, Python 3.8.10 is the final regular maintenance release. Starting now, the 3.8 branch will only accept security fixes and releases of those will be made in source-only form until October 2024. To keep receiving regular bug fixes, please upgrade to Python 3.9.

Compared to the 3.7 series, this last regular bugfix release is relatively dormant at 92 commits since 3.8.9. Version 3.7.8, the final regular bugfix release of Python 3.7, included 187 commits. But there’s a bunch of important updates here regardless, the biggest being macOS Big Sur and Apple Silicon build support. This work would not have been possible without the effort of Ronald Oussoren, Ned Deily, Maxime Bélanger, and Lawrence D’Anna from Apple. Thank you!

Take a look at the change log for details.

We hope you enjoy the new releases

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

Python 3.10.0a7 is now available for testing

2021-04-06T07:30:00.006-04:00

Brrrrr… do you feel that? That’s the chill of beta freeze coming closer. Meanwhile, your friendly CPython release team doesn’t rest even on holidays and we have prepared a shiny new release for you: Python 3.10.0a7.

Get the new release here:

https://www.python.org/downloads/release/python-3100a7/

Python 3.10.0a7

Release Date: April 5, 2021

This is an early developer preview of Python 3.10

Major new features of the 3.10 series, compared to 3.9

Python 3.10 is still in development. This release, 3.10.0a7 is the last of seven planned alpha releases. Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process. During the alpha phase, features may be added up until the start of the beta phase (2021-05-03) and, if necessary, may be modified or deleted up until the release candidate phase (2021-10-04). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.10 are still being planned and written. Among the new major new features and changes so far:

PEP 623 – Deprecate and prepare for the removal of the wstr member in PyUnicodeObject.
PEP 604 – Allow writing union types as X | Y
PEP 612 – Parameter Specification Variables
PEP 626 – Precise line numbers for debugging and other tools.
bpo-38605: from __future__ import annotations (PEP 563) is now the default.
PEP 618 – Add Optional Length-Checking To zip.
bpo-12782: Parenthesized context managers are now officially allowed.
PEP 632 – Deprecate distutils module.
PEP 613 – Explicit Type Aliases
PEP 634 – Structural Pattern Matching: Specification
PEP 635 – Structural Pattern Matching: Motivation and Rationale
PEP 636 – Structural Pattern Matching: Tutorial
PEP 644 – Require OpenSSL 1.1.1 or newer
PEP 624 – Remove Py_UNICODE encoder APIs
PEP 597 – Add optional EncodingWarning
(Hey, fellow core developer, if a feature you find important is missing from this list, let Pablo know.)

The next pre-release of Python 3.10 will be 3.10.0b1 ( the first beta release and feature freeze ), currently scheduled for Monday, 2021-05-03.

More resources

And now for something completely different

In physics, the twin paradox is a thought experiment in special relativity involving identical twins, one of whom makes a journey into space in a high-speed rocket and returns home to find that the twin who remained on Earth has aged more. This result appears puzzling because each twin sees the other twin as moving, and so, as a consequence of an incorrect and naive application of time dilation and the principle of relativity, each should paradoxically find the other to have aged less. However, this scenario can be resolved by realising that the travelling twin is undergoing acceleration, which makes him a non-inertial observer. In both views, there is no symmetry between the spacetime paths of the twins. Therefore, the twin paradox is not a paradox in the sense of a logical contradiction.

We hope you enjoy those new releases!

Your friendly release team,
Pablo Galindo Salgado @pablogsal
Ned Deily @nad
Steve Dower @steve.dower

Python 3.9.4 hotfix is now available

2021-04-04T15:19:00.000-04:00

Python 3.9.3 was released two days ago on Friday, April 2nd. It contains important security content listed below for reference. Unfortunately, it also introduced an unintentional ABI incompatibility, making some C extensions built with Python 3.9.0 - 3.9.2 crash with Python 3.9.3 on 32-bit systems. To minimize disruption, I decided to recall 3.9.3 and introduce this hotfix release: 3.9.4.

We highly recommend upgrading your Python 3.9 installations to 3.9.4 at your earliest convenience.

Get it here:

https://www.python.org/downloads/release/python-394/

What is “ABI compatibility”?

Python guarantees that within a given language series (like the current 3.9) binary extensions written in C or C++ and compiled against headers of one release (like 3.9.0) will be importable from other versions in the same series (like 3.9.3). If this weren’t the case, library authors would have to ship separate binary wheels on PyPI for every single bugfix release of Python. That would be very inconvenient.

What broke in Python 3.9.3?

In a fix for a corner-case crash around recursion limits and exceptions, the PyThreadState struct needed to change. While PyThreadState’s only documented public member is the *interp field, it’s not uncommon for C extensions to access other fields in this struct as well.

When I approved the backport of this fix, I missed the fact that the variable size change would change the memory layout of said struct on 32-bit systems (on 64-bit systems alignment rules made the size change backwards compatible). Merging the backport was a mistake, and so 3.9.4 reverts it to restore compatibility with binary extensions built against Python 3.9.0 - 3.9.2. Details in bpo-43710.

Security Content in Python 3.9.3

bpo-43631: high-severity CVE-2021-3449 and CVE-2021-3450 were published for OpenSSL, it’s been upgraded to 1.1.1k in CI, and macOS and Windows installers.
bpo-42988: CVE-2021-3426: Remove the getfile feature of the pydoc module which could be abused to read arbitrary files on the disk (directory traversal vulnerability). Moreover, even source code of Python modules can contain sensitive data like passwords. Vulnerability reported by David Schwörer.
bpo-43285: ftplib no longer trusts the IP address value returned from the server in response to the PASV command by default. This prevents a malicious FTP server from using the response to probe IPv4 address and port combinations on the client network. Code that requires the former vulnerable behavior may set a trust_server_pasv_ipv4_address attribute on their ftplib.FTP instances to True to re-enable it.
bpo-43439: Add audit hooks for gc.get_objects(), gc.get_referrers() and gc.get_referents(). Patch by Pablo Galindo.

Release Calendar

Maintenance releases for the 3.9 series will continue at regular bi-monthly intervals, with 3.9.5 planned for May 3rd 2021 as well.

What’s new?

The Python 3.9 series contains many new features and optimizations over 3.8. See the “What’s New in Python 3.9 ” document for more information about features included in the 3.9 series. We also have a detailed change log for 3.9.3 specifically.

Detailed information about all changes made in version 3.8.9 can be found in its respective changelog.

We hope you enjoy those new releases!

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

Python 3.9.3 and 3.8.9 are now available

2021-04-02T13:55:00.009-04:00

Those are expedited security releases, recommended to all users. Get them here:

https://www.python.org/downloads/release/python-389/

Note: 3.9.3 has been recalled due to introducing unintentional ABI incompatibility. Download 3.9.4 instead: https://www.python.org/downloads/release/python-394/.

Security Content

bpo-43631: high-severity CVE-2021-3449 and CVE-2021-3450 were published for OpenSSL, it’s been upgraded to 1.1.1k in CI, and macOS and Windows installers.
bpo-42988: CVE-2021-3426: Remove the getfile feature of the pydoc module which could be abused to read arbitrary files on the disk (directory traversal vulnerability). Moreover, even source code of Python modules can contain sensitive data like passwords. Vulnerability reported by David Schwörer.
bpo-43285: ftplib no longer trusts the IP address value returned from the server in response to the PASV command by default. This prevents a malicious FTP server from using the response to probe IPv4 address and port combinations on the client network. Code that requires the former vulnerable behavior may set a trust_server_pasv_ipv4_address attribute on their ftplib.FTP instances to True to re-enable it.
bpo-43439: Add audit hooks for gc.get_objects(), gc.get_referrers() and gc.get_referents(). Patch by Pablo Galindo.

Release Calendar

Due to the security fixes, those releases are made a month sooner than planned. I decided to keep the release calendar intact, meaning that the last full regular maintenance release of Python 3.8 is still planned for May 3rd 2021, after which it will shift to source releases only for security bug fixes only. Maintenance releases for the 3.9 series will continue at regular bi-monthly intervals, with 3.9.3 planned for May 3rd 2021 as well.

What’s new?

Detailed information about all changes made in version 3.8.9 can be found in its respective changelog.

We hope you enjoy those new releases!

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

Python 3.10.0a6 is now available for testing

2021-03-01T15:08:00.001-05:00

Remember us? It’s your friendly CPython release team and we have something we think you may like: The new alpha release of Python 3.10 is here, now with 100% more pattern matching. If I were you, I would download it and start playing with it. Extra points if you report us any bugs you find along the way! Are you confused about all this pattern matching business? Fear not, this release also includes some fantastic documentation and some shiny new “What’s new” entries.

Check them here and tell us how we can improve it:

https://docs.python.org/3.10/whatsnew/3.10.html

https://docs.python.org/3.10/tutorial/controlflow.html#match-statements

Go get the new alpha here:

https://www.python.org/downloads/release/python-3100a6/

This is an early developer preview of Python 3.10

Major new features of the 3.10 series, compared to 3.9

Python 3.10 is still in development. This release, 3.10.0a6 is the sixth of seven planned alpha releases.
Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process.
During the alpha phase, features may be added up until the start of the beta phase (2021-05-03) and, if necessary, may be modified or deleted up until the release candidate phase (2021-10-04). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.10 are still being planned and written. Among the new major
new features and changes so far:

PEP 623 – Remove wstr from Unicode
PEP 604 – Allow writing union types as X | Y
PEP 612 – Parameter Specification Variables
PEP 626 – Precise line numbers for debugging and other tools.
bpo-38605: from __future__ import annotations (PEP 563) is now the default.
PEP 618 – Add Optional Length-Checking To zip.
bpo-12782: Parenthesized context managers are now officially allowed.
PEP 632 – Deprecate distutils module.
PEP 613 – Explicit Type Aliases
PEP 634 – Structural Pattern Matching: Specification
PEP 635 – Structural Pattern Matching: Motivation and Rationale
PEP 636 – Structural Pattern Matching: Tutorial
(Hey, fellow core developer, if a feature you find important is missing from this list, let Pablo know.)

The next pre-release of Python 3.10 will be 3.10.0a7 ( last alpha release), currently scheduled for Monday, 2021-04-05.

More resources

And now for something completely different

Schwarzschild wormholes, also known as Einstein–Rosen bridges (named after Albert Einstein and Nathan Rosen), are connections between areas of space that can be modelled as vacuum solutions to the Einstein field equations, and that are now understood to be intrinsic parts of the maximally extended version of the Schwarzschild metric describing an eternal black hole with no charge and no rotation. Here, “maximally extended” refers to the idea that the spacetime should not have any “edges”: it should be possible to continue this path arbitrarily far into the particle’s future or past for any possible trajectory of a free-falling particle (following a geodesic in the spacetime).

Although Schwarzschild wormholes are not traversable in both directions, their existence inspired Kip Thorne to imagine traversable wormholes created by holding the “throat” of a Schwarzschild wormhole open with exotic matter (material that has negative mass/energy).

Python 3.9.2 and 3.8.8 are now available

2021-02-19T11:26:00.004-05:00

Convinced of the wonders of free two-day deliveries, I’m pleased to present you Python 3.9.2 and 3.8.8. Get them from:

https://www.python.org/downloads/release/python-392/

https://www.python.org/downloads/release/python-388/

Next up, the last full regular maintenance release of Python 3.8 is planned for May 3rd 2021, after which it will shift to source releases only for security bug fixes only. Maintenance releases for the 3.9 series will continue at regular bi-monthly intervals, with 3.9.3 planned for early May 2021.

Why the expedited final release?

This release, just as the candidate before it, contains two security fixes:

bpo-42938: Avoid static buffers when computing the repr of ctypes.c_double and ctypes.c_longdouble values. This issue was assigned CVE-2021-3177.
bpo-42967: Fix web cache poisoning vulnerability by defaulting the query args separator to &, and allowing the user to choose a custom separator. This issue was assigned CVE-2021-23336.

Since the announcement of the release candidates for 3.9.2 on 3.8.8, we received a number of inquiries from end users urging us to expedite the final releases due to the security content, especially CVE-2021-3177.

This took us somewhat by surprise since we believed security content is cherry-picked by downstream distributors from source either way, and the RC releases provide installers for everybody else interested in upgrading in the meantime. It turns out that release candidates are mostly invisible to the community and in many cases cannot be used due to upgrade processes which users have in place.

In turn, the other active release managers and I decided to stop providing release candidates for bugfix versions. Starting from now on after the initial 3.x.0 final release, all subsequent releases are going to be provided as is in bi-monthly intervals. The release calendar PEPs for 3.8 and 3.9 have been updated accordingly.

On the severity of CVE-2021-3177

We recommend you upgrade your systems to Python 3.8.8 or 3.9.2.

Our understanding is that while the CVE is listed as “remote code execution”, practical exploits of this vulnerability as such are very unlikely due the following conditions needing to be met for successful RCE:

pass an untrusted floating point number from a remote party to ctypes.c_double.from_param (note: Python floating point numbers were not affected);
have that object be passed to repr() (for instance through logging);
have that float point number be valid machine code;
have the buffer overflow overwrite the stack at exactly the right place for the code to get executed.

In fact, Red Hat’s evaluation of the vulnerability was consistent with ours. They write: “the highest threat from this vulnerability is to system availability.”

To be sure, denial of service through malicious input is also a serious issue. Thus, to help the community members for whom the release candidate was insufficient, we are releasing the final versions of 3.9.2 and 3.8.8 today.

What’s new?

The Python 3.9 series contains many new features and optimizations over 3.8. See the “What’s New in Python 3.9 2” document for more information about features included in the 3.9 series. We also have a detailed change log for 3.9.2rc1 specifically. The final release only contains a single bugfix over the release candidate.

Detailed information about all changes made in version 3.8.8rc1 specifically can be found in its respective changelog. The final version contains no changes over the release candidate.

We hope you enjoy those new releases!

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

Python 3.9.2rc1 and 3.8.8rc1 are now available for testing

2021-02-17T07:50:00.005-05:00

I’m happy to announce two release candidates today: Python 3.9.2rc1, and Python 3.8.8rc1. Get them from:

https://www.python.org/downloads/release/python-392rc1/

https://www.python.org/downloads/release/python-388rc1/

Unless critical issues are discovered, both release candidates will become their respective final versions on Monday, March 1st.

Following that, the last full regular maintenance release of Python 3.8 is planned for May 3rd 2021, after which it will shift to source releases only for security bug fixes only. Maintenance releases for the 3.9 series will continue at regular bi-monthly intervals, with 3.9.3 planned for early May 2021.

Notable security content in today’s releases

bpo-42967: Fix web cache poisoning vulnerability by defaulting the query args separator to &, and allowing the user to choose a custom separator.
bpo-42938: Avoid static buffers when computing the repr of ctypes.c_double and ctypes.c_longdouble values.

What’s new?

The Python 3.9 series contains many new features and optimizations over 3.8. See the “What’s New in Python 3.9” document for more information about features included in the 3.9 series. We also have a detailed change log for 3.9.2rc1 specifically.

Detailed information about all changes made in version 3.8.8rc1 specifically can be found in its change log.

We hope you enjoy those new releases!

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

Python 3.7.10 and 3.6.13 security updates now available

2021-02-15T23:59:00.003-05:00

Python 3.7.10 and 3.6.13, the lastest security fix rollups for Python 3.7 and Python 3.6, are now available. You can find the release files, links to the changelogs, and more information here:

https://www.python.org/downloads/release/python-3710/
https://www.python.org/downloads/release/python-3613/

These releases are source code only; Windows and macOS binary installers are not provided for security fix releases.

Note that Python 3.9 is now the latest feature release series of Python 3. You should consider upgrading to 3.9 as soon as practical. Get the latest release of 3.9.x here.

Python 3.10.0a5 is now available for testing

2021-02-03T05:59:00.005-05:00

Well, this one took a bit more time due to some surprise last time reference leaks and release blockers to fix, but now Python 3.10.0a5 it’s here. Will this be the first release announcements of the 3.10 series without copy-paste typos? Go get it here:

https://www.python.org/downloads/release/python-3100a5/

This is an early developer preview of Python 3.10

Major new features of the 3.10 series, compared to 3.9

Python 3.10 is still in development. This release, 3.10.0a5 is the fifth of seven planned alpha releases. Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process. During the alpha phase, features may be added up until the start of the beta phase (2021-05-03) and, if necessary, may be modified or deleted up until the release candidate phase (2021-10-04). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.10 are still being planned and written. Among the new major new features and changes so far:

PEP 623 – Remove wstr from Unicode
PEP 604 – Allow writing union types as X | Y
PEP 612 – Parameter Specification Variables
PEP 626 – Precise line numbers for debugging and other tools.
bpo-38605: from __future__ import annotations (PEP 563 ) is now the default.
PEP 618 – Add Optional Length-Checking To zip.
bpo-12782 : Parenthesized context managers are now officially allowed.
(Hey, fellow core developer, if a feature you find important is missing from this list, let Pablo know.)

The next pre-release of Python 3.10 will be 3.10.0a6, currently scheduled for 2021-03-01.

More resources

And now for something completely different

The Chandrasekhar limit is the maximum mass of a stable white dwarf star. White dwarfs resist gravitational collapse primarily through electron degeneracy pressure, compared to main sequence stars, which resist collapse through thermal pressure. The Chandrasekhar limit is the mass above which electron degeneracy pressure in the star’s core is insufficient to balance the star’s own gravitational self-attraction. Consequently, a white dwarf with a mass greater than the limit is subject to further gravitational collapse, evolving into a different type of stellar remnant, such as a neutron star or black hole. Those with masses up to the limit remain stable as white dwarfs. The currently accepted value of the Chandrasekhar limit is about 1.4 M☉ (2.765×1030 kg). So we can be safe knowing that our sun is not going to become a black hole!

Python 3.10.0a4 is now available for testing

2021-01-04T16:37:00.004-05:00

Happy new year to all of you. I hope you all have a great start of the year! And how to best celebrate that we have left 2020 behind that with a new Python alpha release? :) Go get it here:

https://www.python.org/downloads/release/python-3100a4/

This is an early developer preview of Python 3.10

Major new features of the 3.10 series, compared to 3.9

Python 3.10 is still in development. This releasee, 3.10.0a4 is the second 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 (2021-05-03) and, if necessary, may be modified or deleted up until the release candidate phase (2021-10-04). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.10 are still being planned and written. Among the new major
new features and changes so far:

PEP 623 – Remove wstr from Unicode
PEP 604 – Allow writing union types as X | Y
PEP 612 – Parameter Specification Variables
PEP 626 – Precise line numbers for debugging and other tools.
bpo-38605: from __future__ import annotations (PEP 563) is now the default.
PEP 618 – Add Optional Length-Checking To zip.
(Hey, fellow core developer, if a feature you find important is missing from this list, let Pablo know.)

The next pre-release of Python 3.10 will be 3.10.0a5, currently scheduled for 2021-02-01.

More resources

And now for something completely different

The Majumdar–Papapetrou spacetime is one surprising solution of the coupled Einstein-Maxwell equations that describe a cluster of static charged black holes with the gravitational and the electrostatic forces cancelling each other out. Each one of these many black holes of the multi-black holes system has a spherical topology and follows the Reissner–Nordström metric. Unsurprisingly, the movement of a test particle in such spacetime is not only a very chaotic system but also has some fractals hiding the complexity of its movement.

Python 3.8.7 is now available

2020-12-21T14:36:00.007-05:00

Python 3.8.7 is the seventh maintenance release of Python 3.8. Go get it here:

https://www.python.org/downloads/release/python-387/

Note: this is a bugfix release for the 3.8 series which was superseded by Python 3.9, currently the latest feature release series of Python 3. You can find the latest release of 3.9.x here.

Maintenance releases for the 3.8 series will continue at regular bi-monthly intervals, with 3.8.8 planned for February 2021.

macOS 11 Big Sur not fully supported

Python 3.8.7 is not yet fully supported on macOS 11 Big Sur. It will install on macOS 11 Big Sur and will run on Apple Silicon Macs using Rosetta 2 translation. However, a few features do not work correctly, most noticeably those involving searching for system libraries (vs user libraries) such as ctypes.util.find_library() and in Distutils. This limitation affects both Apple Silicon and Intel processors. We are looking into improving the situation for Python 3.8.8.

Python 3.9.1 provides full support for Big Sur and Apple Silicon Macs, including building natively on Apple Silicon Macs and support for universal2 binaries.

What’s new?

The Python 3.8 series contains many new features and optimizations over 3.7. 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 3.8.7 specifically can be found in its change log. Note that compared to 3.8.6 this release also contains all changes present in 3.8.7rc1.

We hope you enjoy Python 3.8!

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

Python 3.9.1 is now available, together with 3.10.0a3 and 3.8.7rc1

2020-12-07T20:36:00.004-05:00

It’s starting to get very cold (at least on the Northern hemisphere) so we have been carefully packaging a total of three new Python releases to keep you warm these days!

Python 3.9.1

Python 3.9.1 is the first maintenance release of Python 3.9, and also the first version of Python to support macOS 11 Big Sur natively on Apple Silicon. Go get it here.

Maintenance releases for the 3.9 series will continue at regular bi-monthly intervals, with 3.9.2 planned for Monday, 2021-02-08.

Python 3.10.0a3

Python 3.10a3 is the third alpha release of Python 3.10. You can get it here:

Python 3.8.7rc1

Python 3.8.7rc1 is the release preview of the next maintenance release of Python 3.8. You can get it here.

Assuming no critical problems are found prior to 2020-12-21 , the currently scheduled release date for 3.8.7 , 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 3.8.7 and as such its main purpose is testing.

And now for something completely different

In mathematics, a Borwein integral is an integral whose unusual properties were first presented by mathematicians David Borwein and Jonathan Borwein in 2001. These integrals are remarkable for exhibiting apparent patterns that eventually break down. The following is an example:

This pattern continues up to

At the next step the obvious pattern fails,

Your friendly release team,

Ned Deily
Steve Dower
Pablo Galindo
Łukasz Langa

Releasing pip 20.3, featuring new dependency resolver

2020-11-30T07:53:00.004-05:00

On behalf of the Python Packaging Authority and the pip team, I am pleased to announce that we have just released pip 20.3, a new version of pip. You can install it by running python -m pip install --upgrade pip.

This is an important and disruptive release -- we explained why in a blog post last year. We've even made a video about it.

Highlights

DISRUPTION: Switch to the new dependency resolver by default. Watch out for changes in handling editable installs, constraints files, and more: https://pip.pypa.io/en/latest/user_guide/#changes-to-the-pip-dependency-resolver-in-20-3-2020
DEPRECATION: Deprecate support for Python 3.5 (to be removed in pip 21.0).
DEPRECATION: pip freeze will stop filtering the pip, setuptools, distribute and wheel packages from pip freeze output in a future version. To keep the previous behavior, users should use the new --exclude option.
Substantial improvements in new resolver for performance, output and error messages, avoiding infinite loops, and support for constraints files.
Support for PEP 600: Future manylinux Platform Tags for Portable Linux Built Distributions.
Documentation improvements: Resolver migration guide, quickstart guide, and new documentation theme.
Add support for MacOS Big Sur compatibility tags.

The new resolver is now on by default for Python 3 users. It 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 see our guide on how to test and migrate, and how to report issues. You can use the deprecated (old) resolver, using the flag --use-deprecated=legacy-resolver, until we remove it in the pip 21.0 release in January 2021.

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

Coming soon: end of Python 2.7 support

We aim to release pip 21.0 in January 2021, per our release cadence. At that time, pip will stop supporting Python 2.7 and will therefore stop supporting Python 2 entirely.

When users use pip 20.3 in a Python 2 environment, the old dependency resolver is still the default.

For more info or to contribute:

We run this project as transparently as possible, so you can:

read and participate in GitHub issues
contribute to our user experience work: sign up to become a member of the UX Studies group (after you join, we'll notify you about future UX surveys and interviews)
contact us in the Discourse forum or Zulip chat
read our meeting notes

Thank you

Thanks to our contractors on this project: Simply Secure (specifically Georgia Bullen, Bernard Tyers, Nicole Harris, Ngọc Triệu, and Karissa McKelvey), Changeset Consulting (Sumana Harihareswara), Atos (Paul F. Moore), Tzu-ping Chung, Pradyun Gedam, and Ilan Schnell. Thanks also to Ernest W. Durbin III at the Python Software Foundation for liaising with the project.

This award continues our relationship with Mozilla, which supported Python packaging tools with a Mozilla Open Source Support Award in 2017 for Warehouse. Thank you, Mozilla! (MOSS has a number of types of awards, which are open to different sorts of open source/free software projects. If your project will seek financial support in 2021, do check the MOSS website to see if you qualify.)

This is new funding from the Chan Zuckerberg Initiative. This project is being made possible in part by a grant from the Chan Zuckerberg Initiative DAF, an advised fund of Silicon Valley Community Foundation. Thank you, CZI! (If your free software/open source project is seeking funding and is used by researchers, check the Joint Roadmap for Open Science Tools Rapid Response Fund and consider applying.)

The funding for pip's overhaul will end at the end of 2020; if your organization wants to help continue improvements in Python packaging, please join the sponsorship program.

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, to the PSF and the Packaging WG, and to all the contributors and volunteers who work on or use Python packaging tools.

-Sumana Harihareswara, pip project manager

Python 3.10.0a2 is now available for testing

2020-11-04T09:58:00.006-05:00

The engines of the secret release manager machine have finished producing a new pre-release. Go get it here:

https://www.python.org/downloads/release/python-3100a2/

This is an early developer preview of Python 3.10

Major new features of the 3.10 series, compared to 3.9

Python 3.10 is still in development. This releasee, 3.10.0a2 is the second 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 (2021-05-03) and, if necessary, may be modified or deleted up until the release candidate phase (2021-10-04). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.10 are still being planned and written. Among the new major
new features and changes so far:

PEP 623 – Remove wstr from Unicode
PEP 604 – Allow writing union types as X | Y
PEP 612 – Parameter Specification Variables
PEP 626 – Precise line numbers for debugging and other tools.
bpo-38605: from __future__ import annotations (PEP 563) is now the default.
(Hey, fellow core developer, if a feature you find important is missing from this list, let Pablo know.)

The next pre-release of Python 3.10 will be 3.10.0a3, currently scheduled for 2020-12-07.

More resources

And now for something completely different

The cardinality (the number of elements) of infinite sets can be one of the most surprising results of set theory. For example, there are the same amount of even natural numbers than natural numbers (which can be even or odd). There is also the same amount of rational numbers than natural numbers. But on the other hand, there are more real numbers between 0 and 1 than natural numbers! All these sets have infinite cardinality but turn out that some of these infinities are bigger than others. These infinite cardinalities normally are represented using aleph numbers. Infinite sets are strange beasts indeed.

Your friendly release team,
Ned Deily @nad
Steve Dower @steve.dower
Pablo Galindo Salgado @pablogsal

Python 3.9.0 is now available, and you can already test 3.10.0a1!

2020-10-05T16:09:00.005-04:00

On behalf of the Python development community and the Python 3.9 release team, I’m pleased to announce the availability of Python 3.9.0.

Python 3.9.0 is the newest feature release of the Python language, and it contains many new features and optimizations. You can find Python 3.9.0 here:

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

Most third-party distributors of Python should be making 3.9.0 packages available soon.

See the “What’s New in Python 3.9” document for more information about features included in the 3.9 series. Detailed information about all changes made in 3.9.0 can be found in its change log.

Maintenance releases for the 3.9 series will follow at regular bi-monthly intervals starting in late November of 2020.

OK, boring! Where is Python 4?

Not so fast! The next release after 3.9 will be 3.10. It will be an incremental improvement over 3.9, just as 3.9 was over 3.8, and so on.

In fact, our newest Release Manager, Pablo Galindo Salgado, prepared the first alpha release of what will become 3.10.0 a year from now. You can check it out here:

https://www.python.org/downloads/release/python-3100a1/

We hope you enjoy the new releases!

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

More resources

Online Documentation
PEP 596, 3.9 Release Schedule
PEP 619, 3.10 Release Schedule
Report bugs at https://bugs.python.org.
Help fund Python and its community.

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