如何检查文件是否存在于所有子目录中？

import os

def check_file_in_subdirectories(file_name, directory):
    for root, dirs, files in os.walk(directory):
        if file_name in files:
            return True
    return False

# 调用示例
file_name = "example.txt"
directory = "/path/to/directory"
result = check_file_in_subdirectories(file_name, directory)
if result:
    print("文件存在于所有子目录中")
else:
    print("文件不存在于所有子目录中")