title: Remove all previous versions of python
body: <p>I have some experience with <code>C++</code> and <code>Fortran</code>, and I want to start using <code>python</code> for my post-processing as I am starting to realise how inefficient <code>MATLAB</code> is for what I need to do (mostly involves plots with millions of points). </p>
  
  <p>I already had a few versions of <code>python</code> installed, from every time I wanted to start using. It has now become a mess. In <code>/usr/local/bin/</code>, here is what the command <code>ls python*</code> returns:</p>
  
  <pre><code>python            python2.7         python3           python3.5         python3.5m        pythonw-32
  python-32         python2.7-32      python3-32        python3.5-32      python3.5m-config pythonw2.7 
  python-config     python2.7-config  python3-config    python3.5-config  pythonw           pythonw2.7-32
  </code></pre>
  
  <p>I now want a clean slate. I want a safe way to remove all the previous versions of <code>python</code>, including all of their packages, so I can just install the latest version and import all the libraries I want like <code>numpy</code> and <code>matplotlib</code> smoothly (I had some issues with that). </p>
  
  <p><strong>EDIT:</strong></p>
  
  <p>I am running on OSX Yosemite 10.10.</p>