title: Plotting distribution of time data in Python using Pandas
body: <p>I have a pandas dataframe with some time data which looks like</p>
  
  <pre class="lang-py prettyprint-override"><code>0    08:00 AM
  1    08:15 AM
  2    08:30 AM
  3     7:45 AM
  4     7:30 AM
  </code></pre>
  
  <p>There are 660 rows like these in total (datatype- String). I want to plot the distribution(histogram) of this column. How can I do that? Also some of the rows are just an empty strings (missing data), so I have to also handle that while plotting. What can be the best way to handle that?</p>
  
  <p>I have tried to use <code>pandas.to_datetime()</code> to convert string to timestamp, but still after that I am stuck on how to plot distribution of those timestamps and missing data.</p>