How would you recursively find all files with a specific extension in a directory tree?

You can use os.walk(), glob.glob(), or pathlib.Path.rglob(). Each has different advantages for automation scripts.

# Using pathlib (recommended)
from pathlib import Path

def find_files_by_extension(directory, extension):
    return list(Path(directory).rglob(f'*.{extension}'))

# Using glob
import glob
files = glob.glob('/path/**/*.py', recursive=True)

# Using os.walk
import os
def find_files_walk(directory, extension):
    files = []
    for root, dirs, filenames in os.walk(directory):
        for filename in filenames:
            if filename.endswith(f'.{extension}'):
                files.append(os.path.join(root, filename))
    return files