替换文本文件中最后一次出现的文本字符串

def replace_last_occurrence(file_path, target_string, replacement_string):
    # 读取文本文件
    with open(file_path, 'r') as file:
        content = file.read()

    # 定位最后一次出现的目标字符串
    last_occurrence_index = content.rfind(target_string)

    if last_occurrence_index != -1:
        # 替换目标字符串为新的字符串
        modified_content = content[:last_occurrence_index] + replacement_string + content[last_occurrence_index + len(target_string):]

        # 保存修改后的文本文件
        with open(file_path, 'w') as file:
            file.write(modified_content)
            print("替换成功！")
    else:
        print("未找到目标字符串！")

# 示例用法
replace_last_occurrence("example.txt", "hello", "world")