title: How do I sort a dataframe's columns based on the values in multiple rows?
body: <p>For example, </p>
  
  <pre><code>df = pd.DataFrame({'x':[1,1,1,2,3,3], 'y':['a','a','c','b','b','b']})
  ct = pd.crosstab(df.x, df.y)
  ct
  y  a  b  c
  x         
  1  2  0  1
  2  0  1  0
  3  0  2  0
  </code></pre>
  
  <p>How do I sort the columns of ct based on the values in row1, row2, and row3 (in that order of priority)?</p>
  
  <p>I've tried the following, neither of which work</p>
  
  <pre><code>ct.sort_values([1, 2, 3], axis=1)
  ct.sort_values(['1','2','3'], axis=1)
  </code></pre>