title: python subtract every even column from previous odd column
body: <p>Sorry if this has been asked before -- I couldn't find this specific question.</p>
  
  <p>In python, I'd like to subtract every even column from the previous odd column:</p>
  
  <p>so go from: </p>
  
  <pre><code>292.087 190.238 299.837 189.488 255.525 187.012
  300.837 190.887 299.4   188.488 248.637 187.363
  292.212 191.6   299.038 188.988 249.65  187.5
  300.15  192.4   307.812 189.125 247.825 188.113
  </code></pre>
  
  <p>to</p>
  
  <pre><code>101.849 110.349 68.513
  109.95  110.912 61.274
  100.612 110.05  62.15
  107.75  118.687 59.712
  </code></pre>
  
  <p>There will be an unknown number of columns. should I use something in <code>pandas</code> or <code>numpy</code>?</p>
  
  <p>Thanks in advance.</p>