title: Column operation in python
body: <p>I have a file as below (m,deg,deg)</p>
  
  <pre><code>0   0       5
  10  0.65    12
  20  0.61    14
  30  0.53    3
  40  0.54    6
  </code></pre>
  
  <p>And I want to do operation between rows in same column in python for example third column diff between row, example  (12-5) (14-12) (3-14) (6-3) and so on</p>
  
  <p>Your help is much appreciated</p>