将字符串周围的markdown标记替换为html标记

import re

def markdown_to_html(text):
    # 替换加粗标记
    text = re.sub(r'\*\*(.*?)\*\*', r'<strong>\1</strong>', text)
    
    # 替换斜体标记
    text = re.sub(r'\*(.*?)\*', r'<em>\1</em>', text)
    
    # 替换标题标记
    text = re.sub(r'^(#{1,6})\s(.*)$', r'<h\1>\2</h\1>', text, flags=re.MULTILINE)
    
    # 替换链接标记
    text = re.sub(r'\[(.*?)\]\((.*?)\)', r'<a href="\2">\1</a>', text)
    
    # 替换图片标记
    text = re.sub(r'!\[(.*?)\]\((.*?)\)', r'<img src="\2" alt="\1">', text)
    
    return text