Use fnmatch.filter to filter files by more than one possible file extension

Question

Given the following piece of python code:

for root, dirs, files in os.walk(directory):
    for filename in fnmatch.filter(files, \'*.png\'):
        pass
         


        

Answer 1

You can use a list comprehension to check if my_file matches any of the file masks defined in patterns:

import fnmatch

my_file = 'my_precious.txt'
patterns = ('*.txt', '*.html', '*.mp3')


if [pat for pat in patterns if fnmatch.fnmatch(my_file, pat)]:
    print('We have a match!')
else:
    print('No match')

Answer 2

This would be a better way, perhaps because you are not calling + repeatedly and using a tuple instead of list.

for root, dirs, files in os.walk(directory):
    for extension in ('*.jpg', '*.jpeg', '*.gif', '*.png'):
        for filename in fnmatch.filter(files, extension):
            pass

A tuple is better because you are not going to modify the extension once you have created them. You are just using to iterate over them.