title: Pandas datetime formatting
body: <p>Is it possible to represent a pd.to_datetime with suffix of zeros? It seems the zeros are being removed. </p>
  
  <pre><code>print pd.to_datetime("2000-07-26 14:21:00.00000",
                  format="%Y-%m-%d %H:%M:%S.%f")
  </code></pre>
  
  <p>The result is</p>
  
  <pre><code>2000-07-26 14:21:00
  </code></pre>
  
  <p>The desired result would be</p>
  
  <pre><code>2000-07-26 14:21:00.00000
  </code></pre>
  
  <p>I know the values mean the same thing but it would be nice for consistency.</p>