Question

I’m trying to add a space before every capital letter, except the first one.

Here’s what I have so far, and the output I’m getting:

>>> tex = 'ThisFileName.txt' >>> re.sub('[A-Z].', ' ', tex) ' his ile ame.txt' 

I want: ‘This File Name.txt’

(It’d be nice if I could also get rid of .txt, but I can do that in a separate operation.)

Answer 1

Key concept here is backreferences in regular expressions:

import re text = 'ThisFileName.txt' print re.sub('([a-z])([A-Z])', r'\1 \2', text) # Prints: 'This File Name.txt' 

For pulling off the ‘.txt’ in a reliable way, I recommend os.path.splitext()

import os filename = 'ThisFileName.txt' print os.path.splitext(filename) # Prints: ('ThisFileName', '.txt')