title: pandas dataframe sort columns according to column totals
body: <p>I was able to sort rows according to the last column. However, I also have a row at the bottom of the dataframe which has the totals of each column. I couldn't find a way to sort the columns according to the totals in the last row. The table looks like the following:</p>
  
  <pre><code>   A  B  C  T
  0  9  9  9  27
  1  9  10 4  23
  2  7  4  8  19
  3  2  6  9  17
  T  27 29 30
  </code></pre>
  
  <p>I want this table to be sorted so that the order of columns will be from left to right C, B, A from highest total to lowest. How can this be done?</p>