Transform words in a phrase to hashtags using a whitelist, without changing the upper/lower case characters in the words in the phrase (i.e. if your phrase has "Beer" but your whitelist has "beer", you'll see "#Beer")

whitelist-hashtagger

import re

whitelist = ['quick','lazy','boring']
tweet = "The quick brown fox jumped over the lazy dog. The Quick Brown Fox Jumped Over The Boring Dog"

for item in whitelist:
    tweet = re.compile('('+item+')',re.I).sub(r'#\1', tweet, 1)
    # remove the `1` if you want it to match all instances

print tweet