uppercase - Uppercasing letters after '.', '!' and '?' signs in Python

Question

I have been searching Stack Overflow but cannot find the proper code for correcting e.g.

"hello! are you tired? no, not at all!"

Into:

"Hello! Are you tired? No, not at all!"

Answer 1

You can try this regex approach:

import re
re.sub("(^|[.?!])s*([a-zA-Z])", lambda p: p.group(0).upper(), s)
# 'Hello! Are you tired? No, not at all!'

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• (^|[.?!]) matches the start of the string ^ or .?! followed by optional spaces;
• [a-zA-Z] matches letter directly after the first pattern;
• use lambda function to convert the captured group to upper case;