os.path.isdir question

[Benjamin]

On Mar 16, 2:27 pm, MRAB <goo... at mrabarnett.plus.com> wrote:
> On Mar 16, 2:27 am, Benjamin <musiccomposit... at gmail.com> wrote:
>
> > On Mar 15, 8:12 pm, lampshade <mwolff... at gmail.com> wrote:> Hello,
>
> > > I'm having some problems with  os.path.isdir  I think it is something
> > > simple that I'm overlooking.
>
> > > #!/usr/bin/python
> > > import os
>
> > > my_path = os.path.expanduser("~/pictures/")
> > > print my_path
> > > results = os.listdir(my_path)
> > > for a_result in results:
> > >     if os.path.isdir(str(my_path) + str(a_result)):
>
> > Try if os.path.isdir(os.path.join(my_path, a_result)):>         results.remove(a_result)
>
> > > for x in results: print x
>
> > > The problem is, that the directories are never removed.  Can anyone
> > > point out what I'm missing that is causing the bug?  Is there a better
> > > way of doing this?
>
> > You should always use os.path.join to join paths. You shouldn't add
> > them like normal strings. I suspect you're getting a combination which
> > doesn't exist, so it isn't a dir. :)
>
> You are also removing items from 'results' while iterating over it,
> which has an undefined behaviour. It would be better to build a new
> list of those that aren't directories.

This list comprehension should do the trick pythonically:
final_results = [a_result for a_result in results if
os.path.isdir(os.path.join(my_path, a_result))]