title: find time difference in seconds as an integer with python
body: <p>I need to find the time difference in seconds with python. I know I can get the difference like this:</p>
  
  <pre><code>from datetime import datetime
  now = datetime.now()
  ....
  ....
  ....
  later = datetime.now()
  difference = later-now
  </code></pre>
  
  <p>how do I get difference in total seconds?</p>