title: get format of ISO date input python
body: <p>I am getting a json object, with a string representing the data in this form:
  '2018-07-09T09:58:11.809Z'</p>
  
  <p>What is the format for it?</p>
  
  <p>I've tried:</p>
  
  <pre><code>'%Y %B %d %H %M %S'
  </code></pre>
  
  <p>but i'm not sure what the T and the Z is, and how to work with them.</p>