All standard library functions accepting `str` paths must accept `PathLike` as well

[arhadthedev]

Inspired by gh-3484 that tried to fix this for wave.open() only but failed.

We need a centralized and universal approach instead so everything accepting str paths could automatically accept PathLike for free.

For this, we can amend stdlib functions to wrap their path arguments into pathlib.PurePath introduced in Python 3.4. Unlike os.fspath, it throws a nicely formatted exception for us:

• os.fspath from the mentioned bpo-31412: wave.open takes a path-like object #3484:

  cpython/Lib/aifc.py

  Lines 912 to 918 in 4a82d65

  	try:
  	f = os.fspath(f)
  	except TypeError:
  	if not hasattr(f, 'read') and not hasattr(f, 'write'):
  	raise TypeError('open() takes str, a path-like object, '
  	+ 'or an open file-like object, '
  	+ f'not {type(f).__name__!r}') from None

• PurePath:

  >>> import pathlib
  >>> pathlib.PurePath(16)
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
    File "D:\Oleg\cpython\Lib\pathlib.py", line 267, in __new__
      return cls._from_parts(args)
             ^^^^^^^^^^^^^^^^^^^^^
    File "D:\Oleg\cpython\Lib\pathlib.py", line 316, in _from_parts
      drv, root, parts = self._parse_args(args)
                         ^^^^^^^^^^^^^^^^^^^^^^
    File "D:\Oleg\cpython\Lib\pathlib.py", line 300, in _parse_args
      a = os.fspath(a)
          ^^^^^^^^^^^^
  TypeError: expected str, bytes or os.PathLike object, not int

[ericvsmith]

It’s not clear to me what you’re proposing to change. Can you provide specifics?

How would PurePath(16)’s behavior change?

[encukou]

We need a centralized and universal approach instead so everything accepting str paths could automatically accept PathLike for free.

os.fspath is meant to do just that.

Note that importing pathlib and creating PurePath are relatively expensive operations (compared to os.fspath with strings). When the niceties they provide aren't useful, it's better to avoid them.

Unlike os.fspath, it throws a nicely formatted exception for us:

How can the error message from os.fspath be improved?

[hauntsaninja]

Unlike os.fspath, it throws a nicely formatted exception for us

I'm confused, pathlib.PurePath's error message in the thing you've posted is literally coming straight from os.fspath

[arhadthedev]

Closing in favor of gh-103659.

[arhadthedev]

Reopening after #103659 (comment):

BTW, I don't think #102425 applies here, the os.environ values are strings some of which happen to look like paths (or integers).

However, I'll return to this issue much later.