title: Compute the centroid of a rectangle in python
body: <p>I want to compute the centroid of rectangle, The coordinates of rectangle are as follows:</p>
  
  <pre><code>co_ord = (601, 1006,604, 1009)  ## (xmin,ymin,xmax,ymax)
  </code></pre>
  
  <p>Can someone point to an easy way. 
  Thanks</p>