title: Python: How to pip install opencv2 with specific version 2.4.9?
body: <p>I know that I could <code>pip install opencv-python</code> which installs opencv3, but is there a separate command or name for opencv specific version such as 2.4.9? </p>
  
  <p>If not, how can I specify which version to install?</p>
  
  <p>Thanks.</p>