title: How to switch between python 2.7 to python 3 from command line?
body: <p>I'm trying to find the best way to switch between the two python compilers, 2.7 to 3.3.
  I ran the python script from the cmd like this:</p>
  
  <blockquote>
    <p><code>python ex1.py</code></p>
  </blockquote>
  
  <p>Where do I set the "python" environment in the window's environment variable to point to either python 3.3 or 2.7?</p>
  
  <p>I am wondering if there is an easy way to switch between the two versions from the cmd line? </p>