title: averaging list of lists python column-wise
body: <p>I have a list of lists:
  something like:</p>
  
  <pre><code>data = [[240, 240, 239],
          [250, 249, 237], 
          [242, 239, 237],
          [240, 234, 233]]
  </code></pre>
  
  <p>And I want to average this out like</p>
  
  <pre><code>[average_column_1, average_column_2, average_column_3]
  </code></pre>
  
  <p>My piece of code is like not very elegant.
  It is the naive way of going thru the list, keeping the sum in seperate container and then dividing by number of  elements.</p>
  
  <p>I think there is a pythonic way to do this.
  Any suggestions?
  Thanks</p>