Wrapper around os.walk with directory/file exclusion

exwalk.py

import fnmatch
import os
import re


def exwalk(path, exclude_dirs=(), exclude_files=(), onerror=None):
    """
    Wrapper around os.walk to exclude files and directories using Unix shell-style wildcards with Python's fnmatch
    """
    exclude_dirs_pattern = re.compile(
        '|'.join((fnmatch.translate(exclude_dir) for exclude_dir in exclude_dirs)),
        flags=re.IGNORECASE)
    exclude_files_pattern = re.compile(
        '|'.join((fnmatch.translate(exclude_file) for exclude_file in exclude_files)),
        flags=re.IGNORECASE)

    for root, dirs, files in os.walk(path, onerror=onerror):
        if len(exclude_dirs) > 0:
            dirs[:] = [d for d in dirs if not exclude_dirs_pattern.match(d)]
        if len(exclude_files) > 0:
            files[:] = [f for f in files if not exclude_files_pattern.match(f)]

        yield root, dirs, files