diff --git a/doc/source/groupby.rst b/doc/source/groupby.rst index b5a382ce24342..e517e9ab9935d 100644 --- a/doc/source/groupby.rst +++ b/doc/source/groupby.rst @@ -257,20 +257,21 @@ GroupBy with MultiIndex With :ref:`hierarchically-indexed data `, it's quite natural to group by one of the levels of the hierarchy. +Let's create a series with a two-level ``MultiIndex``. + .. ipython:: python - :suppress: arrays = [['bar', 'bar', 'baz', 'baz', 'foo', 'foo', 'qux', 'qux'], ['one', 'two', 'one', 'two', 'one', 'two', 'one', 'two']] - tuples = list(zip(*arrays)) - tuples - index = pd.MultiIndex.from_tuples(tuples, names=['first', 'second']) + index = pd.MultiIndex.from_arrays(arrays, names=['first', 'second']) s = pd.Series(np.random.randn(8), index=index) + s + +We can then group by one of the levels in ``s``. .. ipython:: python - s grouped = s.groupby(level=0) grouped.sum()