See PEP 585, which is still under review and may change in response to this work.

https://www.python.org/dev/peps/pep-0585/

Submitted a request for consideration by the Steering Council: https://github.com/python/steering-council/issues/21

The SC approved the PEP!

Łukasz, do you want to submit the PR to update the PEP status?

We should get the implementation reviewed (e.g. by Serhiy) and land it before alpha 6 goes out, April 22 (we should aim for a week before at least).

New changeset 48b069a003ba6c684a9ba78493fbbec5e89f10b8 by Guido van Rossum in branch 'master':
bpo-39481: Implementation for PEP 585 (#18239)
https://github.com/python/cpython/commit/48b069a003ba6c684a9ba78493fbbec5e89f10b8

The base implementation has landed. We still need docs, and I'm sure that the alpha and beta release cycle will find small things that need to be improved.

Perhaps the next priority is an update for Doc/whatsnew/3.9.rst.

@gvanrossum is new types going to support generic alias protocol or this subset will be kept? Like typeshed uses os.DirEntry as a generic, but in reality it is not. (https://github.com/python/cpython/pull/17561)

Ethan Smith produced a list of types that are Generic in typeshed but not in the stdlib. So these could be added.

https://github.com/gvanrossum/cpython/pull/1#issuecomment-582781121

New changeset f9dd51e7db27d04e0b716d41a2804d5acbf145d1 by Batuhan Taşkaya in branch 'master':
bpo-39481: Make os.DirEntry generic (GH-19415)
https://github.com/python/cpython/commit/f9dd51e7db27d04e0b716d41a2804d5acbf145d1

New changeset 2fa67df605e4b0803e7e3aac0b85d851b4b4e09a by Batuhan Taşkaya in branch 'master':
bpo-39481: PEP 585 for ipaddress.py (GH-19418)
https://github.com/python/cpython/commit/2fa67df605e4b0803e7e3aac0b85d851b4b4e09a

New changeset 7c4185d62d4aec486d82c3ad02acd878db2d3537 by Ethan Smith in branch 'master':
bpo-39481: PEP 585 for enumerate, AsyncGeneratorType, mmap (GH-19421)
https://github.com/python/cpython/commit/7c4185d62d4aec486d82c3ad02acd878db2d3537

At this speed I can merge about 3 PRs per hour. I'll be back tomorrow.

New changeset e3ec44d692d9442e640cf5b2d8708157a65cec3e by Ethan Smith in branch 'master':
bpo-39481: PEP 585 for difflib, filecmp, fileinput (#19422)
https://github.com/python/cpython/commit/e3ec44d692d9442e640cf5b2d8708157a65cec3e

How are ipaddress and mmap generic?

Check typeshed

New changeset 0361556537686f857f1025ead75e6af4ca7cc94a by Batuhan Taşkaya in branch 'master':
bpo-39481: PEP 585 for a variety of modules (GH-19423)
https://github.com/python/cpython/commit/0361556537686f857f1025ead75e6af4ca7cc94a

I tested the following example:

import ipaddress, mmap

x: ipaddress.IPv4Network[int]
y: mmap.mmap[int]

MyPy produces errors:

t.py:4: error: "IPv4Network" expects no type arguments, but 1 given
t.py:5: error: "mmap" expects no type arguments, but 1 given

This is because mmap and IPv4Network are not generic types in typeshed. _BaseNetwork and _mmap are generic types, but IPv4Network and mmap are normal classes. The former are implementation detail of typeshed. _mmap does not exist in the stdlib, and _BaseNetwork in typeshed and the stdlib are different things.

Hm, yeah it appears my methodology was too loose. Thank you for catching
these. I will go through and test the rest (if you haven't yet) later today
and make a PR to revert anything that needs it. Thanks! (and sorry)

On Mon, Apr 13, 2020 at 2:12 AM Serhiy Storchaka <report@bugs.python.org>
wrote:

>
> Serhiy Storchaka <storchaka+cpython@gmail.com> added the comment:
>
> I tested the following example:
>
> import ipaddress, mmap
>
> x: ipaddress.IPv4Network[int]
> y: mmap.mmap[int]
>
> MyPy produces errors:
>
> t.py:4: error: "IPv4Network" expects no type arguments, but 1 given
> t.py:5: error: "mmap" expects no type arguments, but 1 given
>
> This is because mmap and IPv4Network are not generic types in typeshed.
> _BaseNetwork and _mmap are generic types, but IPv4Network and mmap are
> normal classes. The former are implementation detail of typeshed. _mmap
> does not exist in the stdlib, and _BaseNetwork in typeshed and the stdlib
> are different things.
>
> ----------
>
> _______________________________________
> Python tracker <report@bugs.python.org>
> <https://bugs.python.org/issue39481>
> _______________________________________
>

No, I did not check other changes. These two just looked too suspicious.

New changeset 25a6833f7945f14cad83509ec73954d0ad70bdb1 by Chih-Hsuan Yen in branch 'master':
bpo-39481: fix test_genericalias on Android (GH-19469)
https://github.com/python/cpython/commit/25a6833f7945f14cad83509ec73954d0ad70bdb1

New changeset cecf049673da6a24435acd1a6a3b34472b323c97 by Ethan Smith in branch 'master':
bpo-39481: Make functools.cached_property, partial, partialmethod generic (#19427)
https://github.com/python/cpython/commit/cecf049673da6a24435acd1a6a3b34472b323c97

New changeset 8ef875028a3644a329c87ce420a73793e315143f by Ethan Smith in branch 'master':
bpo-39481: Make weakref and WeakSet generic (GH-19497)
https://github.com/python/cpython/commit/8ef875028a3644a329c87ce420a73793e315143f

New changeset d01628e411752ee6849f862cae66a1c69fe512b7 by Ethan Smith in branch 'master':
bpo-39481: PEP 585 for dataclasses, mailbox, contextvars (GH-19425)
https://github.com/python/cpython/commit/d01628e411752ee6849f862cae66a1c69fe512b7

I went through the list I generated and it seems that the
ipaddress._BaseNetwork and mmap.mmap cases are the only one I saw that
shouldn't be generic. I will submit a PR to revert those. The only item
left after that which I know of is _lru_cache_wrapper.

On Tue, Apr 14, 2020 at 4:14 PM Guido van Rossum <report@bugs.python.org>
wrote:

>
> Guido van Rossum <guido@python.org> added the comment:
>
>
> New changeset d01628e411752ee6849f862cae66a1c69fe512b7 by Ethan Smith in
> branch 'master':
> bpo-39481: PEP 585 for dataclasses, mailbox, contextvars (GH-19425)
>
> https://github.com/python/cpython/commit/d01628e411752ee6849f862cae66a1c69fe512b7
>
>
> ----------
>
> _______________________________________
> Python tracker <report@bugs.python.org>
> <https://bugs.python.org/issue39481>
> _______________________________________
>

Thanks!
-- 
--Guido (mobile)

In commit 0e80b561d442769631d66f1cc8813ac30f97378e a What's New section was added.

New changeset f3a5b7ada0c951f317dbd307de4b410e58d3e1b3 by Batuhan Taskaya in branch 'master':
bpo-39481: remove generic classes from ipaddress/mmap (GH-20045)
https://github.com/python/cpython/commit/f3a5b7ada0c951f317dbd307de4b410e58d3e1b3

This can be closed. It needs docs though; there's a separate issue for that (issue40814).

New changeset b2c0a43699bd9023a69e3fa554f5488a2e17e278 by Saiyang Gou in branch 'master':
bpo-39481: Fix duplicate SimpleQueue type in test_genericalias.py (GH-22619)
https://github.com/python/cpython/commit/b2c0a43699bd9023a69e3fa554f5488a2e17e278

New changeset 1c217652b690c184b43d8e2b6529a60a14e64328 by Saiyang Gou in branch '3.9':
[3.9] bpo-39481: Fix duplicate SimpleQueue type in test_genericalias.py (GH-22619) (#22624)
https://github.com/python/cpython/commit/1c217652b690c184b43d8e2b6529a60a14e64328