title: create a datetime instance of a particular format
body: <p>By default when we create a datetime instance, the format includes microseconds.</p>
  
  <pre><code>&gt;&gt;&gt; from datetime import datetime
  &gt;&gt;&gt; datetime.now()
  datetime.datetime(2017, 6, 19, 16, 13, 7, 415321)
  </code></pre>
  
  <p>If I don't want the microseconds part in the instance then I do this,</p>
  
  <pre><code>&gt;&gt;&gt; str = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
  &gt;&gt;&gt; new_dt = datetime.strptime(str, '%Y-%m-%d %H:%M:%S')
  </code></pre>
  
  <p>So my question here is that is there any way where we can specify the format in which we want the datetime instance to be created rather than converting it to formatted string we want and then converting back to datetime instance.</p>