title: Checking version of OpenCV (cv)
body: <p>I was checking the version of OpenCV installed previously in a system.
  I tried to check using</p>
  
  <pre><code>from cv2 import __version__
  </code></pre>
  
  <p>Its gave me the following error</p>
  
  <blockquote>
    <p>No module named cv2</p>
  </blockquote>
  
  <p>When I tried <code>import cv</code>, it's not giving me error. Is there a way to know the version?</p>