With our initial set of users, we now need to get the friends of each of these users. A friend is a person whom the user is following. The API for this is called friends/ids, and it has both good and bad points. The good news is that it returns up to 5,000 friend IDs in a single API call. The bad news is that you can only make 15 calls every 15 minutes, which means it will take you at least 1 minute per user to get all followers—more if they have more than 5,000 friends (which happens more often than you may think).

The code is similar to the code from our previous API usage (obtaining tweets). We will package it as a function, as we will use this code in the next two sections. Our function takes a twitter user's ID value, and returns their friends. While it may be surprising to some, many Twitter users have more than 5,000 friends. Due to this we will need to use Twitter's pagination function, which lets Twitter return multiple pages of data through...