title: How to solve "type object 'datetime.datetime' has no attribute 'timedelta'" when creating a new date?
body: <p>I'm using Django and Python 3.7.  I'm trying to calculate a new datetime by adding a number of seconds to an existing datetime.  From this -- <a href="https://stackoverflow.com/questions/100210/what-is-the-standard-way-to-add-n-seconds-to-datetime-time-in-python">What is the standard way to add N seconds to datetime.time in Python?</a>, I thought i could do</p>
  
  <pre><code>new_date = article.created_on + datetime.timedelta(0, elapsed_time_in_seconds)
  </code></pre>
  
  <p>where "article.created_on" is a datetime and "elapsed_time_in_seconds" is an integer.  But the above is resulting in an </p>
  
  <pre><code>type object 'datetime.datetime' has no attribute 'timedelta'
  </code></pre>
  
  <p>error.  What am I missing</p>