Issue 38979: ContextVar[str] should return ContextVar class, not None [proxy]

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Issue38979

classification

Title:	ContextVar[str] should return ContextVar class, not None
Type:	behavior	Stage:	resolved
Components:	Extension Modules	Versions:	Python 3.9, Python 3.8, Python 3.7

process

Status:	closed	Resolution:	fixed
Dependencies:		Superseder:
Assigned To:		Nosy List:	Amir, asvetlov, miss-islington
Priority:	normal	Keywords:	easy (C), patch

Created on 2019-12-05 13:04 by asvetlov, last changed 2019-12-08 12:49 by asvetlov. This issue is now closed.

Pull Requests
URL	Status	Linked	Edit
PR 17497	merged	Amir, 2019-12-07 13:10
PR 17505	closed	miss-islington, 2019-12-08 11:36
PR 17506	merged	miss-islington, 2019-12-08 11:36
PR 17507	merged	miss-islington, 2019-12-08 12:25

Messages (8)
msg357850 - (view)	Author: Andrew Svetlov (asvetlov) *	Date: 2019-12-05 13:04
The issue is minor, I suspect nobody wants to derive from ContextVar class. The generic implementation for __class_getitem__ is returning unmodified self argument. Yuri, is there a reason to behave differently in the case of ContextVar? If no, we can mark the issue as easy(C) and wait for a volunteer, the fix seems trivial.
msg357877 - (view)	Author: Yury Selivanov (yselivanov) *	Date: 2019-12-05 18:18
> The issue is minor, I suspect nobody wants to derive from ContextVar class. I don't think that's allowed, actually. > The generic implementation for __class_getitem__ is returning unmodified self argument. Yuri, is there a reason to behave differently in the case of ContextVar? No, just an oversight, probably.
msg357887 - (view)	Author: Florian Dahlitz (DahlitzFlorian) *	Date: 2019-12-05 20:02
I'd be happy to work on this!
msg357963 - (view)	Author: Amir Mohamadi (Amir) *	Date: 2019-12-07 09:07
@asvetlov I have a question! Should "contextvar_cls_getitem" function be changed? And can you please help me figure out how to change it?
msg357964 - (view)	Author: Andrew Svetlov (asvetlov) *	Date: 2019-12-07 10:28
I think it should look like the corresponding function from multidict: https://github.com/aio-libs/multidict/blob/master/multidict/_multidict.c#L803-L808 Please note, the method definition also should be updated, see https://github.com/aio-libs/multidict/blob/master/multidict/_multidict.c#L923-L928 for inspiration.
msg357997 - (view)	Author: miss-islington (miss-islington)	Date: 2019-12-08 11:36
New changeset 28c91631c24e53713ad0e8a2bbae716373f5e53d by Miss Islington (bot) (AMIR) in branch 'master': bpo-38979: fix ContextVar "__class_getitem__" method (GH-17497) https://github.com/python/cpython/commit/28c91631c24e53713ad0e8a2bbae716373f5e53d
msg357998 - (view)	Author: miss-islington (miss-islington)	Date: 2019-12-08 11:53
New changeset 9baa870c27b54c26f9dd292c26936b70bdb64a06 by Miss Islington (bot) in branch '3.7': bpo-38979: fix ContextVar "__class_getitem__" method (GH-17497) https://github.com/python/cpython/commit/9baa870c27b54c26f9dd292c26936b70bdb64a06
msg358001 - (view)	Author: miss-islington (miss-islington)	Date: 2019-12-08 12:49
New changeset 960fca1a5887a277fd6031cf4c4b6fb31b08ebf5 by Miss Islington (bot) in branch '3.8': bpo-38979: fix ContextVar "__class_getitem__" method (GH-17497) https://github.com/python/cpython/commit/960fca1a5887a277fd6031cf4c4b6fb31b08ebf5

History
Date	User	Action	Args
2019-12-08 12:49:21	asvetlov	set	status: open -> closed resolution: fixed stage: patch review -> resolved
2019-12-08 12:49:11	miss-islington	set	messages: + msg358001
2019-12-08 12:25:10	miss-islington	set	pull_requests: + pull_request16984
2019-12-08 11:53:11	miss-islington	set	messages: + msg357998
2019-12-08 11:36:40	miss-islington	set	pull_requests: + pull_request16983
2019-12-08 11:36:33	miss-islington	set	pull_requests: + pull_request16982
2019-12-08 11:36:06	miss-islington	set	nosy: + miss-islington messages: + msg357997
2019-12-07 13:10:38	Amir	set	keywords: + patch stage: patch review pull_requests: + pull_request16975
2019-12-07 10:28:55	asvetlov	set	messages: + msg357964
2019-12-07 09:07:51	Amir	set	nosy: + Amir, - gvanrossum, yselivanov, levkivskyi, DahlitzFlorian messages: + msg357963
2019-12-05 20:02:04	DahlitzFlorian	set	nosy: + DahlitzFlorian messages: + msg357887
2019-12-05 18:33:32	levkivskyi	set	keywords: + easy (C)
2019-12-05 18:19:20	serhiy.storchaka	set	nosy: + gvanrossum, levkivskyi
2019-12-05 18:18:11	yselivanov	set	messages: + msg357877
2019-12-05 13:04:29	asvetlov	set	type: behavior
2019-12-05 13:04:18	asvetlov	create