Mailman 3 March 2021 - Python-Dev

Re: PEP 637 - Support for indexing with keyword arguments: request for feedback for SC submission
by Thor Whalen 02 Mar '21

02 Mar '21

Finally! One of my top python wishes! Where can I vote? How can I get my hands on a back port? How can I help getting this sooner?

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Python 3.10.0a6 is available, now with 100% more pattern matching
by Pablo Galindo Salgado 02 Mar '21

02 Mar '21

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: What's new: https://docs.python.org/3.10/whatsnew/3.10.html Tutorial: 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](https://www.python.org/dev/peps/pep-0623/) -- Remove wstr from Unicode * [PEP 604](https://www.python.org/dev/peps/pep-0604/) -- Allow writing union types as X | Y * [PEP 612](https://www.python.org/dev/peps/pep-0612/) -- Parameter Specification Variables * [PEP 626](https://www.python.org/dev/peps/pep-0626/) -- Precise line numbers for debugging and other tools. * [bpo-38605](https://bugs.python.org/issue38605): `from __future__ import annotations` ([PEP 563](https://www.python.org/dev/peps/pep-0563/)) is now the default. * [PEP 618 ](https://www.python.org/dev/peps/pep-0618/) -- Add Optional Length-Checking To zip. * [bpo-12782](https://bugs.python.org/issue12782): Parenthesized context managers are now officially allowed. * [PEP 632 ](https://www.python.org/dev/peps/pep-0632/) -- Deprecate distutils module. * [PEP 613 ](https://www.python.org/dev/peps/pep-0613/) -- Explicit Type Aliases * [PEP 634 ](https://www.python.org/dev/peps/pep-0634/) -- Structural Pattern Matching: Specification * [PEP 635 ](https://www.python.org/dev/peps/pep-0635/) -- Structural Pattern Matching: Motivation and Rationale * [PEP 636 ](https://www.python.org/dev/peps/pep-0636/) -- Structural Pattern Matching: Tutorial * <small>(Hey, **fellow core developer,** if a feature you find important is missing from this list, [let Pablo know](mailto:pablogsal@python.org ).)</small> 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 * [Online Documentation](https://docs.python.org/3.10/) * [PEP 619](https://www.python.org/dev/peps/pep-0619/), 3.10 Release Schedule * Report bugs at [https://bugs.python.org](https://bugs.python.org). * [Help fund Python and its community](/psf/donations/). # 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). Regards from rainy London, Pablo Galindo Salgado

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[RELEASE] Python 3.10.0a6 is available, now with 100% more pattern matching
by Pablo Galindo Salgado 02 Mar '21

02 Mar '21

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: What's new: https://docs.python.org/3.10/whatsnew/3.10.html Tutorial: 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/ *Note: The alpha was officially released yesterday, but my email client failed to deliver this email to the mailing lists so I am reposting it.* **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](https://www.python.org/dev/peps/pep-0623/) -- Remove wstr from Unicode * [PEP 604](https://www.python.org/dev/peps/pep-0604/) -- Allow writing union types as X | Y * [PEP 612](https://www.python.org/dev/peps/pep-0612/) -- Parameter Specification Variables * [PEP 626](https://www.python.org/dev/peps/pep-0626/) -- Precise line numbers for debugging and other tools. * [bpo-38605](https://bugs.python.org/issue38605): `from __future__ import annotations` ([PEP 563](https://www.python.org/dev/peps/pep-0563/)) is now the default. * [PEP 618 ](https://www.python.org/dev/peps/pep-0618/) -- Add Optional Length-Checking To zip. * [bpo-12782](https://bugs.python.org/issue12782): Parenthesized context managers are now officially allowed. * [PEP 632 ](https://www.python.org/dev/peps/pep-0632/) -- Deprecate distutils module. * [PEP 613 ](https://www.python.org/dev/peps/pep-0613/) -- Explicit Type Aliases * [PEP 634 ](https://www.python.org/dev/peps/pep-0634/) -- Structural Pattern Matching: Specification * [PEP 635 ](https://www.python.org/dev/peps/pep-0635/) -- Structural Pattern Matching: Motivation and Rationale * [PEP 636 ](https://www.python.org/dev/peps/pep-0636/) -- Structural Pattern Matching: Tutorial * <small>(Hey, **fellow core developer,** if a feature you find important is missing from this list, [let Pablo know](mailto:pablogsal@python.org ).)</small> 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 * [Online Documentation](https://docs.python.org/3.10/) * [PEP 619](https://www.python.org/dev/peps/pep-0619/), 3.10 Release Schedule * Report bugs at [https://bugs.python.org](https://bugs.python.org). * [Help fund Python and its community](/psf/donations/). # 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). Regards from rainy London, Pablo Galindo Salgado

1 0

Which thing is "Development Mode"
by Coyot Linden 02 Mar '21

02 Mar '21

As of 3.7, there is now a python feature called Development Mode: https://docs.python.org/3/library/devmode.html#devmode Which has a confusingly similar and nearly identical name to a setuptools feature: https://packaging.python.org/guides/distributing-packages-using-setuptools/… It seems like a bit of bikeshedding could create a name for one of them that disambiguates them. Best, coyot

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Have virtual environments led to neglect of the actual environment?
by Random832 01 Mar '21

01 Mar '21

I was reading a discussion thread <https://gist.github.com/tiran/2dec9e03c6f901814f6d1e8dad09528e> about various issues with the Debian packaged version of Python, and the following statement stood out for me as shocking: Christian Heimes wrote: > Core dev and PyPA has spent a lot of effort in promoting venv because we don't want users to break their operating system with sudo pip install. I don't think sudo pip install should break the operating system. And I think if it does, that problem should be solved rather than merely advising users against using it. And why is it, anyway, that distributions whose package managers can't coexist with pip-installed packages don't ever seem to get the same amount of flak for "damaging python's brand" as Debian is getting from some of the people in the discussion thread? Why is it that this community is resigned to recommending a workaround when distributions decide the site-packages directory belongs to their package manager rather than pip, instead of bringing the same amount of fiery condemnation of that practice as we apparently have for *checks notes* splitting parts of the stdlib into optional packages? Why demand that pip be present if we're not going to demand that it works properly? I think that installing packages into the actual python installation, both via distribution packaging tools and pip [and using both simultaneously - the Debian model of separated dist-packages and site-packages folders seems like a reasonable solution to this problem] can and should be a supported paradigm, and that virtual environments [or more extreme measures such as shipping an entire python installation as part of an application's deployment] should ideally be reserved for the rare corner cases where that doesn't work for some reason. How is it that virtual environments have become so indispensable, that no-one considers installing libraries centrally to be a viable model anymore? Are library maintainers making breaking changes too frequently, reasoning that if someone needs the old version they can just venv it? Is there some other cause?

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Python-Dev March 2021