title: How to split a panda's column with conditional
body: <p>I have a Log df, in that df i have the column Description. Looks like.</p>
  
  <pre><code>Description
  Machine x : Turn off
  Another action here
  Another action here
  Machine y : Turn off
  Machine x : Turn on
  Another action here
  </code></pre>
  
  <p>And I need split just rows with ":"</p>
  
  <p>Like:</p>
  
  <pre><code>Description               Machine           Action
  Machine x : Turn off      Machine x         Turn off
  Another action here
  Another action here
  Machine y : Turn off      Machine y         Turn off
  Machine x : Turn on       Machine x         Turn on
  Another action here
  </code></pre>
  
  <p>I already tried:</p>
  
  <pre><code>s = df["Description"].apply(lambda x:x.split(":"))
  df["Action"] = s.apply(lambda x: x[1])
  df["Machine"] = s.apply(lambda x: x[0])
  </code></pre>
  
  <p>And something with "startswith".</p>