[Python-Dev] pathlib - current status of discussions (original) (raw)

Ethan Furman ethan at stoneleaf.us
Thu Apr 14 10:47:20 EDT 2016

On 04/14/2016 12:03 AM, Michael Mysinger via Python-Dev wrote:

Brett Cannon writes:

After playing with and considering the 4 possibilities, anything where fspath can return bytes seems like insanity that flies in the face of everything Python 3 is trying to accomplish. In particular, one RichPath class might return bytes and another str, or even worse the same class might sometimes return bytes and sometimes str. When will os.path.join blow up due to mixing bytes and str and when will it work in those situations?

What are you asking here? Exactly where in os.join mixing bytes & str the exception will occur, or will mixing bytes & str ever work?

The answer to the first is irrelevant (except for performance).

The answer to the second is always/never. Meaning allowing os.fspath() and fspath to return either bytes or str will never cause the combination of bytes and str to work. Said another way: if you are using os.path.join then all the pieces have be str or all the pieces have to be bytes.

-- Ethan

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