[Python-Dev] Defining a path protocol

[Paul Moore]

On 6 April 2016 at 23:46, Brett Cannon <brett at python.org> wrote:
> str(path) will definitely work, path.__path__ will work if you're running
> the next set of bugfix releases. fspath(path) will only work in Python 3.6
> and newer.

Ah, that was something I hadn't appreciated, that the builtin would be
3.6+ whereas the protocol would be added to current bugfix releases.

>> Maybe a compatibility library could
>> add
>>
>> try:
>>     fspath
>> except NameError:
>>     try:
>>         import pathlib
>>         def fspath(p):
>>             if isinstance(p, pathlib.Path):
>>                 return str(p)
>>             return p
>>     except ImportError:
>>         def fspath(p):
>>             return p
>>
>> It's messy, like all compatibility code, but it allows code to use
>> fspath(p) in older versions.
>
>
> I would tweak it to check for __fspath__ before it resorted to calling
> str(), but yes, that could be something people use.

Yeah, the above code assumes that if the builtin isn't available, nor
will the protocol be (see my misunderstanding above).

Paul