title: python: sort a list of lists by an item in the sublist
body: <p>I have a list of lists that contains users and scores as follows:</p>
  
  <pre><code>[["user1", 100], ["user2", 234], ["user3", 131]...]
  </code></pre>
  
  <p>I want to produce a list that sorts the users by score in declining order: </p>
  
  <pre><code>[["user2", 234], ["user3", 131], ["user1", 100]...]
  </code></pre>
  
  <p>How might I go about doing this kind of sort?</p>