Finding last occurrence of substring in string, replacing that

Question

So I have a long list of strings in the same format, and I want to find the last \".\" character in each one, and replace it with \". - \". I\'ve tried using rfind, but I can\'t

Answer 1

I would use a regex:

import re
new_list = [re.sub(r"\.(?=[^.]*$)", r". - ", s) for s in old_list]