See Which Twitterers Don’t Follow You Back (updated)
It turns out that if you were following more than 100 people or had more than 100 followers, there was a bug in my script to check who on Twitter doesn’t follow you back. Since I’m not super popular and have less than 100 for both, it took me a while to figure this out.
The getFriends and getFollowers api methods in python-twitter are paginated to 100 results per call, so I needed to modify the script to loop over the paginated results. If I was doing anything more complicated I’d probably use tweepy because it’s a more robust api wrapper, but whatever.
Also, my follower/followee count is still less than 100, so feel free to let me know if this doesn’t work, or follow me an twitter so I can test it myself :)