title: How to select columns from groupby object in pandas?
body: <p>I grouped my dataframe by the two columns below</p>
  
  <pre><code>df = pd.DataFrame({'a': [1, 1, 3],
                     'b': [4.0, 5.5, 6.0],
                     'c': [7L, 8L, 9L],
                     'name': ['hello', 'hello', 'foo']})
  df.groupby(['a', 'name']).median()
  </code></pre>
  
  <p>and the result is:</p>
  
  <pre><code>            b    c
  a name            
  1 hello  4.75  7.5
  3 foo    6.00  9.0
  </code></pre>
  
  <p>How can I access the <code>name</code> field of the resulting median (in this case <code>hello, foo</code>)? This fails:</p>
  
  <pre><code>df.groupby(['a', 'name']).median().name
  </code></pre>