[Python-ideas] Working with Path objects: p-strings?

[Koos Zevenhoven]

On Sat, Mar 26, 2016 at 4:03 PM, Michel Desmoulin <desmoulinmichel at gmail.com
> wrote:

> [...]
> Now with pathlib you don't have to wonder about whether the feature you
> are looking for is on "os", "os.path" or "glob" or "open". You don't
> have to deal the file opening for such a small script. You don't have to
> switch between functions and methods all the time and have to choose
> between nested function calls or intermediary variables.
>
>
Here we completely agree. I used to do scripting of filesystem-intensive
tasks with bash, because it felt more natural, partly because I was doing
that before I started using Python for anything. Due to pathlib I now do
this stuff in Python, which I of course like better for other reasons.
Pretty much everything is there, and nicely auto-completed in editors. The
fact that you can do / for joining paths is not necessarily better than a
method (which exists too as .joinpath()), but it works and may be easy to
remember.


> The pathlib version is way easier to figure out without knowing the
> stdlib by heart, it is one line shorter and one level of indent less.
> And you can discover it all from iPython with ".<tab>":
>
> import sys
> import pathlib
>
> root = pathlib.Path(sys.argv[1])
>
> files = []
> for path in root.glob('*.mp3'):
>
>     name = str(path).replace(path.suffix, '.*')
>     files.append(str(path.absolute()))
>
>     for to_remove in root.glob(name):
>         if to_remove.suffix != ".mp3":
>             to_remove.unlink()
>
> (root / 'playlist.m3u8').write_text('\n'.join(files))
>
>
Or even cleaner, and hopefully easier to understand (not tested, sorry):

 import sys
 import pathlib

 root = pathlib.Path(sys.argv[1])
 files = [f.absolute() for f in root.glob("*.mp3")]

 for mp3file in files:
     for f in root.glob(mp3file.stem + ".*"):
         if f.suffix != ".mp3":
             f.unlink() # remove non-mp3 version

 (root / "playlist.m3u8").write_text("\n".join(files))


Yes, some of the properties could have more logical names like .remove()
instead of .unlink(), and there could be even more functionality.
Subclassing from str would have obvious benefits, but I'm just not sure
whether it's a good idea to inherit things like str.find, str.splitlines,
str.title, ...

So maybe the best thing is not to inherit from str but to make Path quack
as much like a str-duck as possible (and vice versa?) without introducing
confusing things?

BTW, here's a link to issue #22570 (Better stdlib support for Path objects)
http://www.psf.upfronthosting.co.za/issue22570

 - Koos
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-ideas/attachments/20160326/0d846b0b/attachment.html>