[Python-Dev] Pathlib enhancements - acceptable inputs and outputs for __fspath__ and os.fspath()

[Random832]

On Thu, Apr 14, 2016, at 03:02, Stephen J. Turnbull wrote:
> I have a strong preference for str only, because I still don't see a
> use case for polymorphic __fspath__.

Ultimately we're talking about redundancy and performance here. The "use
case" such as there is one, is if there's a class (be it DirEntry or
whatever else) that natively stores bytes, and __fspath__ has to return
str, then it calls fsdecode and then open immediately turns around and
calls fsencode on the result, accomplishing nothing vs just passing
everything straight through.