title: How do I stack two DataFrames next to each other in Pandas?
body: <p>I have two sets of stock data in DataFrames:</p>
  
  <pre><code>&gt; GOOG.head()
             Open   High    Low 
  Date                                                                            
  2011-01-03  21.01  21.05  20.78 
  2011-01-04  21.12  21.20  21.05 
  2011-01-05  21.19  21.21  20.90 
  2011-01-06  20.67  20.82  20.55 
  2011-01-07  20.71  20.77  20.27
  
  AAPL.head()
                Open    High     Low
  Date                              
  2011-01-03  596.48  605.59  596.48
  2011-01-04  605.62  606.18  600.12
  2011-01-05  600.07  610.33  600.05
  2011-01-06  610.68  618.43  610.05
  2011-01-07  615.91  618.25  610.13
  </code></pre>
  
  <p>and I would like to stack them next two each other in a single DataFrame so I can access and compare columns (e.g. High) across stocks (GOOG vs. AAPL)? What is the best way to do this in Pandas and access the subsequent columns (e.g. GOOG's High column and AAPL's High column). Thanks!</p>