title: Using pandas.Dataframe.groupby without alphabetical ordering
body: <p>I have a dataframe that I want to alter (according to the code right below) but it put's all the 'Experiment' name values in alphabetical order. Is there a way to leave the order as it is after calling <strong>pandas.Dataframe.groupby</strong>?</p>
  
  <pre><code>df = df.groupby(['Experiment', 'Step'], as_index=False)['value'].aggregate(np.sum)
  </code></pre>