[Python-Dev] file system path protocol PEP

[Koos Zevenhoven]

On Thu, May 12, 2016 at 12:28 AM, Nikolaus Rath <Nikolaus at rath.org> wrote:
> On May 11 2016, Brett Cannon <brett at python.org> wrote:
>> This PEP proposes a protocol for classes which represent a file system
>> path to be able to provide a ``str`` or ``bytes`` representation.
> [...]
>
> As I said before, to me this seems like a lot of effort for a very
> specific use-case. So let me put forward two hypothetical scenarios to
> better understand your position:

I think you are touching important points.

> - A new module for URL handling is added to the standard library (or
>   urllib is suitably extended). There is a proposal to add a new
>   protocol that allows classes to provide a ``str`` or ``bytes``
>   representation of URLs.

This reminds me of the thread I recently started on python-ideas about
extending the concept of paths to URLs. I don't know if you are
referring to something like that or not.

Anyway, it would be important to know whether the str or bytes
representation is to be used a file system path or an URL, so that
would need to be a separate protocol. But everyone would have the
experience from these discussions, so hopefully less discussion then
:). (By the way, this is one reason to have 'fs' in the name of the
__fspath__ method, although I have not mentioned it before.)

>
> - A new (third-party) library for natural language processing arises
>   that exposes a specific class for representing audio data. Existing
>   language processing code just uses bytes objects. To ease transition
>   and interoperability, it is proposed to add a new protocol for classes
>   that represend audio data to provide a bytes representation.
>
> Do you think you would you be in favor of adding these protocols to
> the stdlib/languange reference as well? If not, what's the crucial
> difference to file system paths?
>

File system paths are very fundamental, and will probably be used in
context of your natural language example too.

-- Koos

>
> Thanks,
> -Nikolaus