title: How to remove levels from a multi-indexed dataframe?
body: <p>For example, I have:</p>
  
  <pre><code>In [1]: df = pd.DataFrame([8, 9],
                            index=pd.MultiIndex.from_tuples([(1, 1, 1),
                                                             (1, 3, 2)]),
                            columns=['A'])
  
  In [2] df
  Out[2]: 
         A
  1 1 1  8
    3 2  9
  </code></pre>
  
  <p>Is there a better way to remove the last level from the index than this:</p>
  
  <pre><code>In [3]: pd.DataFrame(df.values,
                       index=df.index.droplevel(2),
                       columns=df.columns)
  Out[3]: 
       A
  1 1  8
    3  9
  </code></pre>