如何用Python为Markdown中的列表标题添加粗体格式？

核心思路 #

通过正则表达式匹配所有符合特征的列表标题（有序列表开头如1. 、无序列表开头如* 或+ ，且以冒号结尾），然后为匹配内容添加粗体格式。

具体步骤 #

• 编写正则匹配规则
  使用以下正则表达式匹配目标行：

  ^((?:\d+\.|\*|\+)\s*.+?:)
  

  规则说明：

  • ^：匹配行的起始位置
  • (?:\d+\.|\*|\+)：匹配有序列表标记（数字+句号）或无序列表标记（*或+），不捕获该部分
  • \s*：匹配标记后的任意空白字符
  • .+?:：匹配到冒号为止的标题内容
  • 整个括号内的内容会被捕获，用于后续替换

• Python代码实现替换
  使用re.sub()函数执行替换操作，将捕获的内容用粗体标记包裹：

  import re
  
  text = '<div style="padding: 10px; border: 1px solid #e5e7eb; font-size: .95rem; border-radius: 8px"><h3>Income Statement</h3>
  
  1. Total Revenue:
  
  The total revenue for xxxx for the year ended December 31, 2022 was $xxxxx million.
  
  2. Revenue by Source:
  
  The breakdown of xxxx\'s revenue by source for the year ended December 31, 2022 is as follows:
  
  * Billboard:
  	+ Static displays: $xxxx.x million
  	+ Digital displays: $xxxx million
  	+ Other: $xxx million
  	Total billboard revenues: $xxxx million
  * Transit:
  	+ Static displays: $xxxx million
  	+ Digital displays: $xxxxx million
  	+ Other: $xxx million
  	Total transit revenues: $xxxxxxxxx million
  * Sports marketing and other: $xxxxx million
  
  Total revenues: $xxxxx million
  
  </div>'
  
  # 替换为Markdown粗体格式
  updated_text = re.sub(r'^((?:\d+\.|\*|\+)\s*.+?:)', r'**\1**', text, flags=re.MULTILINE)
  
  # 若需HTML粗体格式，可替换为：
  # updated_text = re.sub(r'^((?:\d+\.|\*|\+)\s*.+?:)', r'<strong>\1</strong>', text, flags=re.MULTILINE)
  
  print(updated_text)
  

• 替换效果示例
  处理后符合条件的标题会变为粗体：

  1. Total Revenue:

  The total revenue for xxxx for the year ended December 31, 2022 was $xxxxx million.

  2. Revenue by Source:

  The breakdown of xxxx's revenue by source for the year ended December 31, 2022 is as follows:

  * Billboard:
  + Static displays: $xxxx.x million
  + Digital displays: $xxxx million
  + Other: $xxx million
  Total billboard revenues: $xxxx million

内容的提问来源于stack exchange，提问作者apprunner2186