Python: How can I find all files with a particular extension?

Question

I am trying to find all the .c files in a directory using Python.

I wrote this, but it is just returning me all files - not just .c files.

Answer 1

import os, re
cfile = re.compile("^.*?\.c$")
results = []

for name in os.listdir(directory):
    if cfile.match(name):
        results.append(name)

Answer 2

Just to be clear, if you wanted the dot character in your search term, you could've escaped it too:

'.*[backslash].c' would give you what you needed, plus you would need to use something like:

results.append(f), instead of what you had listed as results += [f]

Answer 3

Try "glob":

>>> import glob
>>> glob.glob('./[0-9].*')
['./1.gif', './2.txt']
>>> glob.glob('*.gif')
['1.gif', 'card.gif']
>>> glob.glob('?.gif')
['1.gif']

Answer 4

There is a better solution that directly using regular expressions, it is the standard library's module fnmatch for dealing with file name patterns. (See also glob module.)

Write a helper function:

import fnmatch
import os

def listdir(dirname, pattern="*"):
    return fnmatch.filter(os.listdir(dirname), pattern)

and use it as follows:

result = listdir("./sources", "*.c")

Answer 5

KISS

# KISS

import os

results = []

for folder in gamefolders:
    for f in os.listdir(folder):
        if f.endswith('.c'):
            results.append(f)

print results

Answer 6

If you replace '.c' with '[.]c$', you're searching for files that contain .c as the last two characters of the name, rather than all files that contain a c, with at least one character before it.

Edit: Alternatively, match f[-2:] with '.c', this MAY be computationally cheaper than pulling out a regexp match.