title: Doing math with Python lists
body: <p>I have output like this: </p>
  
  <pre><code>LL= [['a', 2, 3, 4, 13], ['b', 6, 7, 8, 13], ['c', 10, 11, 12, 13]]
  </code></pre>
  
  <p>Instead of "13", I would like to get maximum of elements by "row" using 2, 3 ,4 </p>
  
  <p>where ['a', 2, 3, 4, 13] would be 4
   ['b', 6, 7, 8, 13], would be 8. </p>
  
  <p>EDIT: I need to replace "13" with the max value.</p>
  
  <p>Then add "14" after 13 </p>
  
  <pre><code>for row in LL: row[5:6] = [14]
  </code></pre>
  
  <p>then replace "14" with a another inter row math.. 
  How can I do this... these are tables but not matrices. 
  Should use Numpy? 
  Ref please so I can look up. </p>