When helping a friend with his code I kept having issues modifying it because of tabs/spaces (my text editors convert tabs to spaces while his doesn't) so I created this script so that I could quickly convert his tabs to spaces.

tabs2spaces.py

import re; from sys import argv

# start the program like this:
# python tabs2spaces.py file_name_to_change.extension

file_name = argv[1]
read = open(file_name,'r+').read()
update = re.sub("[\t]", '    ', read)
save = open(file_name, 'w')
save.write(update)
save.close()