python - 正则表达式多行替换

Question

所以我有这个：

z='===hello  
there===,  
how are ===you===?'

我想成为：

z='<b>hello  
there<\b>,  
how are <b>you<\b>?'

我试过这样做：

z = re.sub(r"\={3}([^\$]+)\={3}", r"<b> \\1 </b>", z, re.M)  

它有点工作，但我得到了这个：

z='<b>hello  
there===,  
how are ===you<\b>?'  

我对此仍然很陌生，但我相信它是^and$使它匹配字符串的开头和结尾。那么如何更改它以使其与中间的匹配？

Answer 1

re.sub(r"\={3}([^\$]+?)\={3}", r"<b> \\1 </b>", z, re.M)

从python doc复制点击这里：

*?, +?, ?? The '*', '+', and '?' qualifiers are all greedy; they match as much text as possible. Sometimes this behaviour isn’t desired; if the RE <.*> is matched against '<H1>title</H1>', it will match the entire string, and not just '<H1>'. Adding '?' after the qualifier makes it perform the match in non-greedy or minimal fashion; as few characters as possible will be matched. Using .*? in the previous expression will match only '<H1>'.