title: ModuleNotFoundError: No module named 'Cython'
body: <p>Why does <code>Cython</code> not want to work ? I've <code>pip</code> installed it and when I try to <code>import</code> it, it just won't work.</p>
  
  <p>I'm using MacOS Version 10.12.6 (16G29)</p>
  
  <p>Here's even a screenshot:</p>
  
  <hr>
  
  <p><a href="https://i.stack.imgur.com/Nx1bs.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Nx1bs.png" alt="enter image description here"></a></p>