[issue35498] Parents objects in pathlib.Path don't support slices as __getitem__ arguments
Joshua Cannon added the comment: Pretty much the same reason you would want to slice any other sequence. You want some range of values. top_most_3_dirs = myPath.parents[-3:] grandparents_and_beyond = myPath.parents[1:] The same goes for negative indexes. -- ___ Python tracker <https://bugs.python.org/issue35498> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue21041] pathlib.PurePath.parents rejects negative indexes
Joshua Cannon added the comment: > it may explain why negative indices or slices were initially not implemented: > It already looks like the result of a slice. Sure the values of the sequence could be thought of as being increasingly smaller slices of some other sequence, however I don't think it changes the fact that "parents" is a sequence, and sequences have well-defined semantics for negative indices and slices. Semantics which people expect, and have to find smelly workarounds for. -- ___ Python tracker <https://bugs.python.org/issue21041> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue21041] pathlib.PurePath.parents rejects negative indexes
Joshua Cannon added the comment: I created issue35498 about .parents rejecting slices as well. (It was pointed out this discussion would probably decide that issue's fate) I think that .parents looking like a duck, but not quacking like one isn't very pythonic. Besides, the fact that p.parents[len(p.parents)-2] is allowed but p.parents[-2] is not just seems like extra steps. There's also list(p.parents)[-2], which is still not ideal. In either case, I'd imagine authors to put a comment like "PathLib .parents doesn't support negative indexes", which goes to show clients are expecting negative indices to work. I see that this issue is several years old. I'm happy to shepherd it if it needs further contributions. -- nosy: +thejcannon ___ Python tracker <https://bugs.python.org/issue21041> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue35498] Parents objects in pathlib.Path don't support slices as __getitem__ arguments
Joshua Cannon added the comment: If it is deemed a bug which needs to be fixed, I've gone ahead and attached the PR to fix it. CLA signage is pending approval at the company I work for, with most people out for the holidays (so it might be a day or two turnaround). -- ___ Python tracker <https://bugs.python.org/issue35498> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue35498] Parents objects in pathlib.Path don't support slices as __getitem__ arguments
Change by Joshua Cannon : -- keywords: +patch pull_requests: +10401 stage: -> patch review ___ Python tracker <https://bugs.python.org/issue35498> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue35498] Parents objects in pathlib.Path don't support slices as __getitem__ arguments
New submission from Joshua Cannon : I would expect the following to work: ``` >>> import pathlib >>> pathlib.Path.cwd().parents[0:1] Traceback (most recent call last): File "", line 1, in File "...\Python36\lib\pathlib.py", line 593, in __getitem__ if idx < 0 or idx >= len(self): TypeError: '<' not supported between instances of 'slice' and 'int' ``` Since pathlib documents `parents` as a sequence-type, and slicing a sequence is pretty standard behavior. -- components: Library (Lib) messages: 331841 nosy: thejcannon priority: normal severity: normal status: open title: Parents objects in pathlib.Path don't support slices as __getitem__ arguments type: enhancement versions: Python 3.6 ___ Python tracker <https://bugs.python.org/issue35498> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
