如何编写全文目录脚本？

import re

def generate_table_of_contents(file_path):
    # 读取文档内容
    with open(file_path, 'r') as file:
        content = file.read()

    # 提取标题
    titles = re.findall(r'(# .+)', content)

    # 构建目录
    table_of_contents = []
    for title in titles:
        level = title.count('#') - 1
        text = title.strip('#').strip()
        link = '#' + '-'.join(text.lower().split())
        table_of_contents.append((level, text, link))

    # 生成链接
    for i, (level, text, link) in enumerate(table_of_contents):
        indent = '  ' * level
        table_of_contents[i] = f'{indent}- [{text}]({link})'

    # 输出目录
    table_of_contents = '\n'.join(table_of_contents)
    output = f'# Table of Contents\n\n{table_of_contents}\n\n{content}'

    # 将目录写入文档
    with open(file_path, 'w') as file:
        file.write(output)

# 使用示例
generate_table_of_contents('example.md')