Is there a single function for matching and replacing?

Question

I wonder if there is a simpler alternative (e.g. a single function call) for matching and replacing to the following example:

>>> import re
>>> 
>>> line = 'file:///windows-d/academic%20discipline/study%20objects/areas/formal%20systems/math'
>>> 
>>> match = re.match(r'^file://(.*)$', line)
>>> if match and match.group(1):
...     substitution = re.sub(r'%20', r' ', match.group(1))
... 
>>> substitution
'/windows-d/academic discipline/study objects/areas/formal systems/math'

Thanks.

Answer 1

I'm going to dodge your regex question and suggest you use something else for this:

>>> line = 'file:///windows-d/academic%20discipline/study%20objects/areas/formal%20systems/math' 
>>> import urllib
>>> urllib.unquote(line)
'file:///windows-d/academic discipline/study objects/areas/formal systems/math'

Then just strip off the file:// with a slice or str.replace if necessary.

%20 (space) is not the only escaped character possible here, so it's better to use the right tool for the job than have your regex solution break later when there is another character needing un-escaping.