[Python-Dev] pathlib - current status of discussions
ethan at stoneleaf.us
Thu Apr 14 10:54:39 EDT 2016
On 04/14/2016 05:16 AM, Victor Stinner wrote:
> I consider that the final goal of the whole discussion is to support
> something like:
> path = os.path.join(pathlib_path, "str_path", direntry)
> Even if direntry uses a bytes filename. I expect genericpath.join() to
> be patched to use os.fspath(). If os.fspath() returns bytes,
> path.join() will fail with an annoying TypeError.
> I expect that DirEntry.__fspath__ uses os.fsdecode() to return str,
> just to make my life easier.
This would be where we strongly disagree. If pathlib, as a high-level
construct, wants to take that approach I have no issues, but the
functions in os are low-level and as such should not be changing data
types unless I ask for it. I see __fspath__ as a retrieval mechanism,
not a data-transformation mechanism.
> You can apply the same rationale for the flavors 2 and 3
> (os.fspath(path, allow_bytes=True)). Indirectly, you will get similar
> TypeError on os.path.join().
And that's fine. Low-level interfaces should not change data types
unless explicitly requested -- and we have fsencode() and fsdecode() for
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