twitter_followers.py

import twitter
api = twitter.Api(consumer_key=consumer_key,
				consumer_secret=consumer_secret,
				access_token_key=access_token,
				access_token_secret=access_secret)

u1 = api.GetFollowerIDs(screen_name='foosel')
u2=api.GetFollowerIDs(screen_name='OctoPrint3D')

print("@foosel follower count : {0}".format(len(u1)))
print("@OctoPrint3D follower count : {0}".format(len(u2)))
print("People following both accounts : {0}".format(len(set(u2).intersection(u1))))