如何用python动态列出一个目录中的所有文件？

import os

def list_files(directory):
    file_list = []
    for root, dirs, files in os.walk(directory):
        for file in files:
            file_list.append(os.path.join(root, file))
    return file_list

directory = '/path/to/directory'
files = list_files(directory)
print(files)