title: How to set Python's default version to 3.x on OS X?
body: <p>I'm running Mountain Lion and the basic default Python version is 2.7. I downloaded Python 3.3 and want to set it as default.</p>
  
  <p>Currently:</p>
  
  <pre><code>$ python
      version 2.7.5
  $ python3.3
      version 3.3
  </code></pre>
  
  <p>How do I set it so that every time I run <code>$ python</code> it opens 3.3?</p>