On 7 May 2018 at 12:35, Chris Angelico <ros...@gmail.com> wrote:
> On Mon, May 7, 2018 at 12:13 PM, Nick Coghlan <ncogh...@gmail.com> wrote:
> > So I have a different suggestion: perhaps it might make sense to propose
> > promoting a key handful of path manipulation operations to the status of
> > being builtins?
> >
> > Specifically, the ones I'd have in mind would be:
> >
> > - dirname (aka os.path.dirname)
> > - joinpath (aka os.path.join)
>
> These two are the basics of path manipulation. +1 for promoting to
> builtins, unless pathlib becomes core (which I suspect isn't
> happening).
>
pathlib has too many dependencies to ever make the type available as a
builtin:
$ ./python -X importtime -c pass 2>&1 | wc -l
25
$ ./python -X importtime -c "import pathlib" 2>&1 | wc -l
53
It's a good way of unifying otherwise scattered standard library APIs, but
it's overkill if all you want to do is to calculate and resolve some
relative paths.
> > - abspath (aka os.path.abspath)
>
> Only +0.5 on this, as it has to do file system operations. It may be
> worthwhile, instead, to promote os.path.normpath, which (like the
> others) is purely processing the string form of the path. It'll return
> the same value regardless of the file system.
>
My rationale for suggesting abspath() over any of its component parts is
based on a few key considerations:
- "make the given path absolute" is a far more common path manipulation
activitity than "normalise the given path" (most users wouldn't even know
what the latter means - the only reason *I* know what it means is because I
looked up the docs for abspath while writing my previous comment)
- __file__ isn't always absolute (especially in __main__), so you need to
be able to do abspath(__file__) in order to reliably apply dirname() more
than once
- it can stand in for both os.getcwd() (when applied to the empty string or
os.curdir) and os.path.normpath() (when the given path is already
absolute), so we get 3 new bits of builtin functionality for the price of
one new builtin name
- I don't want to read "normpath(joinpath(getcwd(), relpath))" when I could
be reading "abspath(relpath)" instead
Cheers,
Nick.
--
Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia
_______________________________________________
Python-ideas mailing list
Python-ideas@python.org
https://mail.python.org/mailman/listinfo/python-ideas
Code of Conduct: http://python.org/psf/codeofconduct/
