Question

Is there an regular expression to find, for example, ">ab" but do not include ">" in the result?

I want to replace some strings using re.sub, and I want to find strings starting with ">" without remove the ">".

Answer 1

You can use a back reference in sub:

import re
test = """
>word
>word2
don't replace
"""
print re.sub('(>).*', r'\1replace!', test)

Outputs:

>replace!
>replace!
don't replace

I believe this accomplishes what you actually want when you say “I want to replace some strings using re.sub, and I want to find strings starting with ‘>‘ without remove the ‘>‘.”