[issue32417] fromutc does not respect datetime subclasses

Jason R. Coombs added the comment: This issue broke a date subclass in the calendra project (https://github.com/jaraco/calendra/issues/11). I acknowledge this change was a known breakage, but I mention it here and link the downstream issue for your information. -- nosy: +jaraco

[issue32417] fromutc does not respect datetime subclasses

Change by Paul Ganssle : -- resolution: -> fixed stage: patch review -> resolved status: open -> closed ___ Python tracker ___ ___

[issue32417] fromutc does not respect datetime subclasses

Łukasz Langa added the comment: New changeset d9503c307a8b6a7b73f6344183602ffb014d3356 by Łukasz Langa (Paul Ganssle) in branch 'master': Add What's New entry for date subclass behavior (#11790) https://github.com/python/cpython/commit/d9503c307a8b6a7b73f6344183602ffb014d3356 --

[issue32417] fromutc does not respect datetime subclasses

Paul Ganssle added the comment: Ah, sorry for the noise, this is a known issue: https://github.com/python/bugs.python.org/issues/12 -- ___ Python tracker ___

[issue32417] fromutc does not respect datetime subclasses

Paul Ganssle added the comment: Hm, when I made the "What's new" issue, it added the same PR to the "Pull requests" 4 times instead of once, and in the history it seems like it *tried* to actually add PR 11790, 11791, 11792 and 11793 (only the first one exists at the moment). Not sure why

[issue32417] fromutc does not respect datetime subclasses

Change by Paul Ganssle : -- pull_requests: +11790, 11791, 11792, 11793 ___ Python tracker ___ ___ Python-bugs-list mailing list

[issue32417] fromutc does not respect datetime subclasses

Change by Paul Ganssle : -- pull_requests: +11790, 11791 ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue32417] fromutc does not respect datetime subclasses

Change by Paul Ganssle : -- pull_requests: +11790, 11791, 11792 ___ Python tracker ___ ___ Python-bugs-list mailing list

[issue32417] fromutc does not respect datetime subclasses

Change by Paul Ganssle : -- pull_requests: +11790 ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue32417] fromutc does not respect datetime subclasses

Change by Eric Snow : -- nosy: +eric.snow ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue32417] fromutc does not respect datetime subclasses

Alexander Belopolsky added the comment: New changeset 89427cd0feae25bbc8693abdccfa6a8c81a2689c by Alexander Belopolsky (Paul Ganssle) in branch 'master': bpo-32417: Make timedelta arithmetic respect subclasses (#10902)

[issue32417] fromutc does not respect datetime subclasses

Change by Guido van Rossum : -- nosy: -gvanrossum ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue32417] fromutc does not respect datetime subclasses

Guido van Rossum added the comment: OK. -- ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue32417] fromutc does not respect datetime subclasses

Paul Ganssle added the comment: > What's the use case for subclassing DateTime? These classes were not designed > with subclassing as a use case in mind. There are several reasons for doing it, of various levels of legitimacy. The overall theme is that people want different behaviors from

[issue32417] fromutc does not respect datetime subclasses

Guido van Rossum added the comment: What's the use case for subclassing DateTime? These classes were not designed with subclassing as a use case in mind. -- nosy: +gvanrossum ___ Python tracker

[issue32417] fromutc does not respect datetime subclasses

Paul Ganssle added the comment: Ah, that's my mistake. I have always been under the impression that "Versions" meant "versions affected", not "versions that this needs to be fixed for". I usually just selected the ones where I had verified that it's a problem. I do not think this should be

[issue32417] fromutc does not respect datetime subclasses

STINNER Victor added the comment: > I am somewhat uneasy about backporting this to Python 2.7 because changing > the return type of `SomeDateTime + timedelta` could be seen as a breaking > change. I have sent a message to the datetime-SIG mailing list about this for > more visibility. You

[issue32417] fromutc does not respect datetime subclasses

Paul Ganssle added the comment: I am somewhat uneasy about backporting this to Python 2.7 because changing the return type of `SomeDateTime + timedelta` could be seen as a breaking change. I have sent a message to the datetime-SIG mailing list about this for more visibility. If it is

[issue32417] fromutc does not respect datetime subclasses

STINNER Victor added the comment: Since the C code is only a few lines, what do you think of also fixing Python 2.7? -- nosy: +vstinner ___ Python tracker ___

[issue32417] fromutc does not respect datetime subclasses

Change by Paul Ganssle : -- keywords: +patch pull_requests: +10142 stage: -> patch review ___ Python tracker ___ ___

[issue32417] fromutc does not respect datetime subclasses

Paul Ganssle added the comment: I've noticed that there's another complicating factor here, which is that addition of `timedelta` does not respect subclasses either, which means that third party libraries implementing fromutc (as was recommended in issue 28602), who will

[issue32417] fromutc does not respect datetime subclasses

New submission from Paul Ganssle : When preparing some tests for how subclasses of date and datetime react as part of a fix for issue 32403, I noticed a fairly big example of where subclass is not preserved - `tzinfo.fromutc`: from datetime import datetime, timezone