title: python pandas sort columns after merge
body: <p>I have merged two pandas dataframes with multiple overlapping columns.  I would like to put the overlapping columns side by side.</p>
  
  <pre><code>merge = df1.merge(df2, how='outer')
  </code></pre>
  
  <p>Output:</p>
  
  <pre><code>A,B,C,D,A_x,B_x,C_x,D_x
  </code></pre>
  
  <p>I would like the output to be:</p>
  
  <pre><code>A,A_x,B,B_x,C,C_x,D,D_x
  </code></pre>
  
  <p>I can do this explicitly but I have many columns and would like a 'dynamic' solution.</p>