如何使用Python递归复制目录中所有具有某个扩展名的文件？

import os
import shutil

def copy_files(source_dir, dest_dir, extension):
    # 遍历源目录中的文件和文件夹
    for file_name in os.listdir(source_dir):
        # 构建文件/文件夹的完整路径
        source_path = os.path.join(source_dir, file_name)
        dest_path = os.path.join(dest_dir, file_name)
        
        # 判断是否为目标文件夹
        if os.path.isdir(source_path):
            # 如果是文件夹，递归调用函数
            copy_files(source_path, dest_path, extension)
        elif os.path.isfile(source_path) and source_path.endswith(extension):
            # 如果是目标文件类型，进行复制
            shutil.copy(source_path, dest_dir)

source_directory = "/path/to/source_directory"
destination_directory = "/path/to/destination_directory"
file_extension = ".txt"

copy_files(source_directory, destination_directory, file_extension)