title: How to force python to import only a specific version of OpenCV?
body: <p>I need to install a specific version of OpenCV. How do I do this at the import stage?</p>
  
  <p>I've seen some people use this method on other packages, and I tried to replicate for opencv, but it did not work... what's the correct statement for this method?...</p>
  
  <pre><code>import pkg_resources
  
  pkg_resources.require("OpenCV==3.3.1")
  
  import cv2
  print('OpenCV version: ', cv2.__version__)
  </code></pre>