[Python-ideas] __dir__ in which folder is this py file

[Nathaniel Smith]

Spit-balling: how about __filepath__ as a
lazily-created-on-first-access pathlib.Path(__file__)?

Promoting os.path stuff to builtins just as pathlib is emerging as
TOOWTDI makes me a bit uncomfortable.

On Sun, May 6, 2018 at 8:29 PM, Nick Coghlan <ncoghlan at gmail.com> wrote:
> On 7 May 2018 at 12:35, Chris Angelico <rosuav at gmail.com> wrote:
>>
>> On Mon, May 7, 2018 at 12:13 PM, Nick Coghlan <ncoghlan at 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   |   ncoghlan at gmail.com   |   Brisbane, Australia
>
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-- 
Nathaniel J. Smith -- https://vorpus.org