title: List of lists in python
body: <p>If I am given two list of lists such as follows:</p>
  
  <pre><code>list1 = [['John',2],
           ['Smith',5],
           ['Kapil',3]]
  
  list2 = [['Smith',2],
           ['John',2],
           ['Stephen',3]]
  </code></pre>
  
  <p>I want a list as follows:</p>
  
  <pre><code>final = [['John',4],
          ['Smith',7],
          ['Kapil',3],
          ['Stephen',3]]
  </code></pre>
  
  <p>which will contain the sum of the numbers if the name has occurred in both list1 and list2.</p>