title: Using .apply() in Sframes to manipulate multiple columns of each row
body: <p>I have an SFrame with the columns Date1 and Date2.</p>
  
  <p>I am trying to use <code>.apply()</code> to find the datediff between Date1 and Date2, but I can't figure out how to use the other argument.</p>
  
  <p>Ideally something like  </p>
  
  <pre><code>frame['new_col'] = frame['Date1'].apply(lambda x: datediff(x,frame('Date2')))
  </code></pre>