title: Convert epoch timestamp to datetime.datetime object
body: <p>I'd like to convert an epoch time stamp (eg, et =1351036517.179364) to a datetime.datetime object.  So far, I've used time.ctime(et) which gives me a string of something like "Fri Oct  5 22:20:33 2012 ". </p>
  
  <p>Eventually, I need the datetime object to compute time difference between two datapoints, the other datapoint is a datetime object as well.</p>
  
  <p>Thanks! </p>