[Python-Dev] file system path protocol PEP

[Sven R. Kunze]

On 13.05.2016 18:43, Chris Angelico wrote:
> https://docs.python.org/3/c-api/unicode.html#c.PyUnicode_Check
>
> https://docs.python.org/3/c-api/unicode.html#c.PyUnicode_CheckExact

Thanks for pointing me at this.
I searched via github and found usages only: 
https://github.com/python/cpython/search?utf8=%E2%9C%93&q=PyUnicode_Check

> "Check" accepts subclasses; "CheckExact" doesn't (it's like "type(x)
> is str"). The question is, which one SHOULD be being done? What should
> this do:
>
> class TmpPath(str):
>      def __fspath__(self):
>          return "/tmp/"+self
> x = TmpPath("foo/bar")
> open(x, "w")
>
> Does that respect __fspath__, or respect the fact that it's a string?

Fine example. Thinking naively, I would say, when somebody made an 
effort to write __fspath__, it should be respected. Maybe, that's just me.

Not sure if that can be a source of errors, when somebody adds str as 
baseclass later because the team needs str functionality. At least I 
would expect __fspath__ to still work .

Best,
Sven