title: Slicing strings in a data frame
body: <p>I have a data frame that looks like this (before).  </p>
  
  <pre><code>BEFORE:
  string
  Oct 05 
  190103  
  </code></pre>
  
  <p>How can I make it look like this (after)?</p>
  
  <pre><code>AFTER:
  string                                  the_date
  Oct 05                                  181005
  190103                                  190103
  </code></pre>