# 正则表达式如果传入正则表达式作为参数,Beautiful Soup会通过正则表达式的`match()`来匹配内容.下面例子中找出所有以b开头的标签,这表示\和\标签都应该被找到: ``` import re for tag in soup.find_all(re.compile("^b")): print(tag.name) # body # b ``` 下面代码找出所有名字中包含”t”的标签: ``` for tag in soup.find_all(re.compile("t")): print(tag.name) # html # title ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://jablack-programs.gitbook.io/python-notes/python-spider/beautifulsoup/sou-suo-wen-dang-shu/guo-lv-qi/zheng-ze-biao-da-shi.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.