list_py_files.py

import os

path = '.'
for dirname, dirnames, filenames in os.walk(path):
    # print path to all filenames with extension py.
    for filename in filenames:
        fname_path = os.path.join(dirname, filename)
        fext = os.path.splitext(fname_path)[1]
        if fext == '.py':
            print fname_path
        else:
            continue