title: timedelta convert to time or int and store it in GAE (python) datastore
body: <p>It looks like this has been covered somewhat in other questions, but I'm still fairly confused on how to actually do this. My lack of experience isn't helping much with that.</p>
  
  <p>I have two DateTimeProperties - StartTime and EndTime. I'm subtracting StartTime from EndTime to get the Duration. From my previous question (thank you to all that answered!) it looks like this operation is producing a timedelta.</p>
  
  <p>There doesn't seem to be an easy way to store timedelta directly in the GAE datastore, so this means I need to convert it either to an int in milliseconds, to a float in seconds or to time.</p>
  
  <p>I will need to do other calculations on this later as well, such as figuring out avg. duration. Based on that, int seems to make the most sense to me right now.</p>
  
  <p>What's the best way to do this or is there a tutorial I can play with?</p>
  
  <p>Thank you! </p>