title: Setting PATH with multiple Python versions under MacOS
body: <p><strong>I would like to make the version of python 2 packaged with MacOS the system default</strong>  Please show me the recommended approach. </p>
  
  <p>I have installed a Python 3 version from miniconda/anaconda, and my current default Python is:</p>
  
  <pre><code>$ which python
  /Users/PatrickT/miniconda3/bin/python 
  </code></pre>
  
  <p>I do not want this to be the default Python anymore. The dilemma is: if I remove conda from the PATH, I can access the Python version packaged with the OS, but then I can no longer access the conda Python...</p>