Difference between os.path.isdir and Path.is_dir

[Kirill Balunov]

чт, 25 июл. 2019 г. в 19:16, Chris Angelico <rosuav at gmail.com>:

> On Fri, Jul 26, 2019 at 1:30 AM Kirill Balunov <kirillbalunov at gmail.com>
> wrote:
> >
> >  Hi all! It is expected that:
> > ```
> > >>> import os
> > >>> from pathlib import Path
> > >>> dummy = " "   # or "" or "     "
> > >>> os.path.isdir(dummy)
> > False
> > >>> Path(dummy).is_dir()
> > True
> > ```
> >
> > or was it overlooked?
> >
> [....]
> I'm not sure if this is considered an important enough bug to actually
> fix, or
> if it's merely a curiosity that occurs when you trigger undocumented
> behaviour.
>
>
No, it's not just because of curiosity. I will try to tell the background,
and maybe I went the wrong way initially. There is a very cool project
https://github.com/3b1b/manim, it allows you to visualize math (I don’t
know how to describe it better you can see some examples here
https://www.3blue1brown.com) and it works lovely on Linux. For some reason,
I need to use it on Windows. Problems began to arise when I tried my
scripts were some latex was included in the animation.
So I installed TexLive, but it didn't produce any output :) In `manim` it
is invoked through a system call
https://github.com/3b1b/manim/blob/master/manimlib/utils/tex_file_writing.py#L40
like this:

$ latex -interaction=batchmode -halt-on-error -output-directory=...
input.tex > /dev/null

For some reason TexLive does not understand Windows relative paths of this
form -output-directory =".\Output" and  ".\Input\file.tex", but it
understands the absolute paths in Windows form like
"C:\path\to\the\input\file.tex".
I read that Windows allows also to provide paths in the usual form
"./Input/file.tex"
(maybe I'm wrong with my understanding what does it mean on Windows), I've
tested and this worked. But the problem is that Python always inserts '\'
as path separators on Windows and there is no control to set it up. I
decided to rewrite all this stuff with the help of `pathlib` module and to
use `Path`  and `.as_posix` method everywhere. Paths are set here
https://github.com/3b1b/manim/blob/c7e6d9d4742ec47098bd86a9bbb4212cc637206b/manimlib/constants.py#L10
and the author uses  `MEDIA_DIR = ""` as a default unset value, and then
checks  `if not os.path.isdir(MEDIA_DIR)`. The documentation states that
`os.path.isdir(...)` is equivalent to `Path(...).is_dir()` but it is not
true. So I wrote here.

with kind regards,
-gdg