I thought it was clever at first, but now I'm feeling that having
mutually exclusive arguments to a single function in this case is
better served by just having two functions. Which also saves us
from ever having to deal with the exception case.
If you have a path that you expect to expect to be a file, it is
confusing to see the traceback where it attempts to listdir because
self.is_file failed and the else was to treat it as a dir.
I prefer this explicit exists check, and explicit dir check.
Yeah, potential for race conditions exists.
I was hesitant at first because of course it can be slow to run,
but previously you'd have to have an if so that you know whether you've
got int or none corresponding to files and folders anyway, so I don't
think the caller-side complexity is increased at all, and saves me from
having to write this as a helper function outside the class.
Only for special cases like preparing to handle permissionerror
would you need to use your own function.
I often found myself writing code like if a.extension == 'png' and
trying to remember if I'm supposed to compare against 'png' or '.png',
and then it would trip up on files like A.PNG because I forgot to
lower() it.
So this class handles all that for you. You can == against it and it
will use os.path.normcase to give you OS-appropriate case sens,
and == works whether you include the dot or not. Then you can use
ext.with_dot or ext.no_dot to get reliably dotted strings.
I am considering some other instance attributes similar to force_sep.
And since these need to be carried over into newly spawned Paths,
I want to consolidate that into a single method so I don't have
to risk forgetting it on a new object.
