bpo-43525: Highlight pathlib operator behavior with anchored paths #24900
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Add a warning describing the behavior of Path objects when combining a Path object with an anchored-path string, using the `/` operator.
| >>> p / '/bin' | ||
| PurePosixPath('/bin') | ||
| >>> p / '/bin' / '/python' | ||
| PurePosixPath('/python') |
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Is this ok? I didn't want to use python3 to not make the example susceptible to bit-rot 😆
I couldn't think of another executable. Maybe a different path would be a better example?
Maybe I'm overthinking it! 😆 🤣
| @@ -217,6 +217,16 @@ The slash operator helps create child paths, similarly to :func:`os.path.join`:: | |||
| >>> '/usr' / q | |||
| PurePosixPath('/usr/bin') | |||
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| Note that a string containing a leading '`/`' character will be considered | |||
| an absolute path, making the last to be taken as the anchor for the new | |||
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"last"? "last one"? The phrasing is copied from pathlib.PurePath:
When several absolute paths are given, the last is taken as an anchor (mimicking os.path.join()’s behaviour):
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This behaviour is already explained a few paragraphs before. |
The way I ran into this caveat was that I replaced naive string concatenations on an old codebase, and changed stuff like this: filepath = ROOT_DIR + "/some_file.txt"Into: root = Path(...)
filepath = root / "/some_file.txt"I missed the leading slash on a few updates, and got the confusing result of I went to read the docs on the Perhaps my suggestion is too verbose? I think it would be good enough without the example. Feel free to close if you don't think the change is worth it at all. |
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Thanks for the PR! I agree that this is too verbose, given that it's been explained a couple paragraphs above.
I'm still sympathetic to the fact that this can be surprising. I opened a different PR that just adds an extra example over here: #100737
Add a warning describing the behavior of Path objects when combining a
Path object with an anchored-path string, using the
/operator.https://bugs.python.org/issue43525