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

I've been using this with a lot of success.

import fnmatch
import functools
import itertools
import os

# Remove the annotations if you're not on Python3
def find_files(dir_path: str=None, patterns: [str]=None) -> [str]:
    """
    Returns a generator yielding files matching the given patterns
    :type dir_path: str
    :type patterns: [str]
    :rtype : [str]
    :param dir_path: Directory to search for files/directories under. Defaults to current dir.
    :param patterns: Patterns of files to search for. Defaults to ["*"]. Example: ["*.json", "*.xml"]
    """
    path = dir_path or "."
    path_patterns = patterns or ["*"]

    for root_dir, dir_names, file_names in os.walk(path):
        filter_partial = functools.partial(fnmatch.filter, file_names)

        for file_name in itertools.chain(*map(filter_partial, path_patterns)):
            yield os.path.join(root_dir, file_name)

Examples:

for f in find_files(test_directory):
    print(f)

yields:

.\test.json
.\test.xml
.\test.ini
.\test_helpers.py
.\__init__.py

Testing with multiple patterns:

for f in find_files(test_directory, ["*.xml", "*.json", "*.ini"]):
    print(f)

yields:

.\test.json
.\test.xml
.\test.ini