title: python datetime timezone .000Z not recognised format
body: <p>I am trying to parse the following date time:</p>
  
  <p><code>stripped_most_recent = 2017-03-22 14:07:50.000Z</code></p>
  
  <p><code>timestamp = (datetime.datetime.strptime(str(stripped_most_recent), "%Y-%m-%d %H:%M:%S.%f"))</code></p>
  
  <p>Returns the following error:</p>
  
  <p><code>ValueError: time data '2017-03-22 14:07:50' does not match format '%Y-%m-%d %H:%M:%S.%f'</code></p>
  
  <p>Whereas, this timestamps causes no problems at all:</p>
  
  <p><code>2017-03-22 14:07:30.181Z</code></p>
  
  <p>I have seen this answer <a href="https://stackoverflow.com/questions/214777/how-do-you-convert-yyyy-mm-ddthhmmss-000z-time-format-to-mm-dd-yyyy-time-forma?noredirect=1&amp;lq=1">here</a>, but dont understand why .000 does not work, whereas anything else is fine. </p>
  
  <p>I think the solution is to remove the .000 completely from the string? As per this <a href="https://stackoverflow.com/questions/19472859/python-convert-datetime-formatted-string-to-seconds">answer</a>: What is the best way to do this? </p>
  
  <p>Thanks, </p>
  
  <p>PS I have also tried:</p>
  
  <p><code>timestamp = (datetime.datetime.strptime(str(stripped_most_recent), "%Y-%m-%d %H:%M:%S.%fZ"))</code></p>