如何在多个文本文件中替换相同的字符？

import os

def replace_characters_in_files(directory, old_char, new_char):
    for filename in os.listdir(directory):
        if filename.endswith(".txt"):
            file_path = os.path.join(directory, filename)
            with open(file_path, "r") as file:
                content = file.read()
            
            new_content = content.replace(old_char, new_char)
            
            with open(file_path, "w") as file:
                file.write(new_content)

# 示例用法
replace_characters_in_files("/path/to/directory", "a", "b")