Searching and Replacing with sub() [and subn()] : sub « Regular Expressions « Python Tutorial

1. Python Tutorial
2. Regular Expressions
3. sub

import re

re.sub('X', 'Mr. Smith', 'attn: X\n\nDear X,\n')
re.subn('X', 'Mr. Smith', 'attn: X\n\nDear X,\n')
print re.sub('X', 'Mr. Smith', 'attn: X\n\nDear X,\n')
re.sub('[ae]', 'X', 'abcdef')
re.subn('[ae]', 'X', 'abcdef')

# Splitting (on Delimiting Pattern) with split()
re.split(':', 'str1:str2:str3')