Python正则表达式，避免跳过括号

Question

I want to replace a regex with '*', but only if the regex is out side of <>. The whole point is to not interfere with the html tags.

I use this to replace:

re.sub(r'SOMEREGEX(?=[^>]*(<|$))', '*', line)

However I ran into his problem: if my regex is:

f.*k

Then this:

fzzzzzzzzz<HTMLTAG>zzzzzzzk

Would become an '*', which I don't want. How do I overcome this problem?

Constraints:

-All brackets are matched

-No nested brackets

-SOMEREGEX is provided by the user. I prefer not changing that.

Answer 1

You could try replacing the . character - "any character at all" - with the character class [^<>] , which matches any character except the angle brackets, <> . This would give the regex f[^<>]*k . This would match facebook but not face<b>book .

There are still things that can go wrong with this, though. Have you considered using a proper HTML parser instead of regular expressions? BeautifulSoup is easy, tasty and fun.

Answer 2

Search between the end and start angle brackets:

re.sub(r'(^|>)f[^<]*k(<|$)', r'\1*\2', line)

The \\1 and \\2 are required to replace the angle brackets that the pattern may have removed from line .