Re: SC Acceptance: PEP 646 -- Variadic Generics

Hi Barry,
That's fantastic news!
Somewhat embarrassingly, on typing-sig we're still discussing one or two final tweaks. In particular, the PEP as accepted forbids a certain construct (passing a tuple of indefinite length to a function using `*args: *Ts`) that after all we may actually want to allow. This would affect static type checkers only, there's no change in the grammar or runtime associated with lifting this restriction. See https://github.com/python/peps/pull/2125
I presume the SC is okay with that?
--Guido
On Wed, Nov 17, 2021 at 2:15 PM Barry Warsaw barry@python.org wrote:
Hello Mark, Matthew, Pradeep, Vincent, and Guido,
The Python Steering Council discussed the latest version of PEP 646 (Variadic Generics) at our last meeting, and have unanimously decided to accept the PEP. Congratulations!
We want to specifically mention that we appreciate the way you called out the Python grammar changes required by the typing features you proposed. As we’ve said before, the Steering Council strongly believes that the typing language and the “general” Python programming language should remain aligned, so the implications of syntax change proposed in the PEP for typing needed to be addressed for non-typed Python as well. The PEP explains this change well, and does a good job of justifying the semantics and usefulness of the change for non-type related purposes.
Please feel free to change the PEP status to Accepted, and to merge your changes to Python 3.11 at your convenience.
With our appreciation, -Barry (on behalf of the Python Steering Council)

Hi Barry,
Absolutely fantastic - thank you for letting us know! As Guido says, there's one final thing that we thought would be easy to resolve but has actually turned out to be a little tricky. Happy to proceed as you think is best here.
Matthew
On Wed, 17 Nov 2021 at 22:33, Guido van Rossum guido@python.org wrote:
Hi Barry,
That's fantastic news!
Somewhat embarrassingly, on typing-sig we're still discussing one or two final tweaks. In particular, the PEP as accepted forbids a certain construct (passing a tuple of indefinite length to a function using `*args: *Ts`) that after all we may actually want to allow. This would affect static type checkers only, there's no change in the grammar or runtime associated with lifting this restriction. See https://github.com/python/peps/pull/2125
I presume the SC is okay with that?
--Guido
On Wed, Nov 17, 2021 at 2:15 PM Barry Warsaw barry@python.org wrote:
Hello Mark, Matthew, Pradeep, Vincent, and Guido,
The Python Steering Council discussed the latest version of PEP 646 (Variadic Generics) at our last meeting, and have unanimously decided to accept the PEP. Congratulations!
We want to specifically mention that we appreciate the way you called out the Python grammar changes required by the typing features you proposed. As we’ve said before, the Steering Council strongly believes that the typing language and the “general” Python programming language should remain aligned, so the implications of syntax change proposed in the PEP for typing needed to be addressed for non-typed Python as well. The PEP explains this change well, and does a good job of justifying the semantics and usefulness of the change for non-type related purposes.
Please feel free to change the PEP status to Accepted, and to merge your changes to Python 3.11 at your convenience.
With our appreciation, -Barry (on behalf of the Python Steering Council)
-- --Guido van Rossum (python.org/~guido) *Pronouns: he/him **(why is my pronoun here?)* http://feministing.com/2015/02/03/how-using-they-as-a-singular-pronoun-can-change-the-world/

I put the PEP back on our agenda to discuss this.
On Wed, Nov 17, 2021 at 2:40 PM Guido van Rossum guido@python.org wrote:
Hi Barry,
That's fantastic news!
Somewhat embarrassingly, on typing-sig we're still discussing one or two final tweaks. In particular, the PEP as accepted forbids a certain construct (passing a tuple of indefinite length to a function using `*args: *Ts`) that after all we may actually want to allow. This would affect static type checkers only, there's no change in the grammar or runtime associated with lifting this restriction. See https://github.com/python/peps/pull/2125
I presume the SC is okay with that?
--Guido
On Wed, Nov 17, 2021 at 2:15 PM Barry Warsaw barry@python.org wrote:
Hello Mark, Matthew, Pradeep, Vincent, and Guido,
The Python Steering Council discussed the latest version of PEP 646 (Variadic Generics) at our last meeting, and have unanimously decided to accept the PEP. Congratulations!
We want to specifically mention that we appreciate the way you called out the Python grammar changes required by the typing features you proposed. As we’ve said before, the Steering Council strongly believes that the typing language and the “general” Python programming language should remain aligned, so the implications of syntax change proposed in the PEP for typing needed to be addressed for non-typed Python as well. The PEP explains this change well, and does a good job of justifying the semantics and usefulness of the change for non-type related purposes.
Please feel free to change the PEP status to Accepted, and to merge your changes to Python 3.11 at your convenience.
With our appreciation, -Barry (on behalf of the Python Steering Council)
-- --Guido van Rossum (python.org/~guido) *Pronouns: he/him **(why is my pronoun here?)* http://feministing.com/2015/02/03/how-using-they-as-a-singular-pronoun-can-change-the-world/ _______________________________________________ Python-Dev mailing list -- python-dev@python.org To unsubscribe send an email to python-dev-leave@python.org https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/YBSS4FJ4... Code of Conduct: http://python.org/psf/codeofconduct/

Thanks, Brett. We'll notify you once we've resolved the issue.
On Thu, 18 Nov 2021 at 19:30, Brett Cannon brett@python.org wrote:
I put the PEP back on our agenda to discuss this.
On Wed, Nov 17, 2021 at 2:40 PM Guido van Rossum guido@python.org wrote:
Hi Barry,
That's fantastic news!
Somewhat embarrassingly, on typing-sig we're still discussing one or two final tweaks. In particular, the PEP as accepted forbids a certain construct (passing a tuple of indefinite length to a function using `*args: *Ts`) that after all we may actually want to allow. This would affect static type checkers only, there's no change in the grammar or runtime associated with lifting this restriction. See https://github.com/python/peps/pull/2125
I presume the SC is okay with that?
--Guido
On Wed, Nov 17, 2021 at 2:15 PM Barry Warsaw barry@python.org wrote:
Hello Mark, Matthew, Pradeep, Vincent, and Guido,
The Python Steering Council discussed the latest version of PEP 646 (Variadic Generics) at our last meeting, and have unanimously decided to accept the PEP. Congratulations!
We want to specifically mention that we appreciate the way you called out the Python grammar changes required by the typing features you proposed. As we’ve said before, the Steering Council strongly believes that the typing language and the “general” Python programming language should remain aligned, so the implications of syntax change proposed in the PEP for typing needed to be addressed for non-typed Python as well. The PEP explains this change well, and does a good job of justifying the semantics and usefulness of the change for non-type related purposes.
Please feel free to change the PEP status to Accepted, and to merge your changes to Python 3.11 at your convenience.
With our appreciation, -Barry (on behalf of the Python Steering Council)
-- --Guido van Rossum (python.org/~guido) *Pronouns: he/him **(why is my pronoun here?)* http://feministing.com/2015/02/03/how-using-they-as-a-singular-pronoun-can-change-the-world/ _______________________________________________ Python-Dev mailing list -- python-dev@python.org To unsubscribe send an email to python-dev-leave@python.org https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/YBSS4FJ4... Code of Conduct: http://python.org/psf/codeofconduct/
participants (3)
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Brett Cannon
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Guido van Rossum
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Matthew Rahtz