A port of https://gist.github.com/simonwhitaker/5748487 to Python

postcode-regex.py

import re

tweet = "Currently chilling out at W1B 2EL, then on to WC2E 8HA or maybe even L1 8JF! :-)"

# Here's a simple regex that tries to recognise postcode-like strings. 
# See http://en.wikipedia.org/wiki/Postcodes_in_the_United_Kingdom#Validation
# for the rules on how UK postcodes are formatted.
postcode_regex = '[A-Z]{1,2}[0-9][0-9A-Z]?\s?[0-9][A-Z]{2}'

postcodes = re.findall(postcode_regex, tweet)

print postcodes