如何在python中遍历目录树，并将扩展名为.py或.txt的文件添加到压缩文件中。

import os
import zipfile

def zip_files(directory, zip_filename):
    with zipfile.ZipFile(zip_filename, 'w') as zipf:
        for root, dirs, files in os.walk(directory):
            for file in files:
                if file.endswith(('.py', '.txt')):
                    file_path = os.path.join(root, file)
                    zipf.write(file_path, os.path.relpath(file_path, directory))

directory = '/path/to/directory'  # 替换为实际的目录路径
zip_filename = 'compressed_files.zip'  # 替换为实际的压缩文件名

zip_files(directory, zip_filename)