pathlib.Path.rglob
Use pathlib.Path.rglob from the the pathlib module, which was introduced in Python 3.5.
from pathlib import Path
for path in Path('src').rglob('*.c'):
print(path.name)
If you don't want to use pathlib, use can use glob.glob('**/*.c'), but don't forget to pass in the recursive keyword parameter and it will use inordinate amount of time on large directories.
For cases where matching files beginning with a dot (.); like files in the current directory or hidden files on Unix based system, use the os.walk solution below.
os.walk
For older Python versions, use os.walk to recursively walk a directory and fnmatch.filter to match against a simple expression:
import fnmatch
import os
matches = []
for root, dirnames, filenames in os.walk('src'):
for filename in fnmatch.filter(filenames, '*.c'):
matches.append(os.path.join(root, filename))