title: How to select the last column of dataframe
body: <p>I have done some searching for the answer to this question, but all I can figure out is this: </p>
  
  <pre><code>df[df.columns[len(df.columns)-1]]
  </code></pre>
  
  <p>which to me seems unweildy, and un-pythonic (and slow?). </p>
  
  <p>What is the easiest way to select the data for the last column in a pandas dataframe without specifying the name of the column?</p>