Python Regexp Sub Function

Question

I am trying to use the sub function in python but cannot get it to work. So far I have

content = '**hello**'
content = re.sub('**(.*)**', '<i>(.*)</i>', content)

I am trying to make the

**hello**

be replaced with

<i>hello</i>

Any ideas?

what is your expected output for something like **foo**bar** — Ashwini Chaudhary
– Ashwini Chaudhary, Commented Oct 13, 2012 at 11:43

Andrew Walker · Accepted Answer · 2012-10-13 12:04:03Z

3

You'll need to escape the * character, and use the replacement function:

content = '**hello**'
content = re.sub('\*\*(.*)\*\*', lambda p : '<i>%s</i>' % p.group(1), content)

As an alternative, you can use named groups.

content = re.sub('\*\*(?P<name>.*)\*\*', '<i>\g<name></i>', '**hello**')

Or as a better alternative, numbered groups.

content = re.sub('\*\*(.*)\*\*', '<i>\\1</i>', '**hello**')

answered Oct 13, 2012 at 11:34

Andrew Walker

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4 Comments

Thanks, but it replaces with (.*) instead of hello

this doesn't gives the required answer.

Thanks, that works perfectly, but say I had hello and I only wanted to match it if it was hello how would I achieve that?

Instead of a replacement function, you could just use r'\1'