title: Python: translating/replacing in a string words that aren't the ones you want
body: <p>Basically, I've got a bunch of phrases and I'm only interested in the ones that contain certain words. What I want to do is 1) find out if that word is there and if it is, 2) erase all the other words. I could do this with a bunch of if's and for's but I was wondering if there'd be a short/pythonic approach to it.</p>