How to use regex with optional characters in python?

Question

Say I have a string

\"3434.35353\"

and another string

\"3593\"

How do I make a single regular expression

Answer 1

You can put a ? after a group of characters to make it optional.

You want a dot followed by any number of digits \.\d+, grouped together (\.\d+), optionally (\.\d+)?. Stick that in your pattern:

import re
print re.match("(\d+(\.\d+)?)", "3434.35353").group(1)

3434.35353

print re.match("(\d+(\.\d+)?)", "3434").group(1)

3434