Efficiently removing subdirectories in dirnames from os.walk

Question

On a mac in python 2.7 when walking through directories using os.walk my script goes through \'apps\' i.e. appname.app, since those are really just directories of themselves

Answer 1

You can do something like this (assuming you want to ignore directories containing '.'):

subdirs[:] = [d for d in subdirs if '.' not in d]

The slice assignment (rather than just subdirs = ...) is necessary because you need to modify the same list that os.walk is using, not create a new one.

Note that your original code is incorrect because you modify the list while iterating over it, which is not allowed.