title: Python Pandas - how to convert string HH:MM:SS.mmm to float sss.ms?
body: <p>I would like to convert string value HH:MM:SS.mmm to float value sec.milliseconds for arithmetic calculations. Is there a direct way to do this as currently I am doing it via split string function and it is a very tedious process. Dataframe looks like:</p>
  
  <pre><code>Col1
  00:00:05.063
  00:01:00.728
  00:03:10.117
  </code></pre>
  
  <p>Output should look like</p>
  
  <pre><code>  5.063
   60.728
  190.117
  </code></pre>
  
  <p>Appreciate any help.</p>