Revert "DOC: Fix the following 'errors' (pandas-dev#24178):"

This reverts commit 41a2e47.

Author: LJArendse

doc/source/groupby.rst

@@ -62,30 +62,16 @@ See the :ref:`cookbook<cookbook.grouping>` for some advanced strategies.
 Splitting an object into groups
 -------------------------------
 
-Pandas objects can be split on any of their axes. The abstract definition of
+pandas objects can be split on any of their axes. The abstract definition of
 grouping is to provide a mapping of labels to group names. To create a GroupBy
-object, see below (more on what the GroupBy object is later). A
-groupby can be applied in the following ways to a pandas object:
-
-* grouped = obj.groupby(key)
-* grouped = obj.groupby(key, axis='columns')
-* grouped = obj.groupby([key1, key2])
+object (more on what the GroupBy object is later), you may do the following:
 
 .. code-block:: python
 
-    df = pd.DataFrame(
-        [('bird', 'Falconiformes', 389.0),
-         ('bird', 'Psittaciformes', 24.0),
-         ('mammal', 'Carnivora', 80.2),
-         ('mammal', 'Primates', np.nan),
-         ('mammal', 'Carnivora', 58)],
-        index=['falcon', 'parrot', 'lion', 'monkey', 'leopard'],
-        columns=('class', 'order', 'max_speed')
-    )
-
-    grouped = df.groupby('class')
-    grouped = df.groupby('order', axis='columns')
-    grouped = df.groupby(['class', 'order'])
+   # default is axis=0
+   >>> grouped = obj.groupby(key)
+   >>> grouped = obj.groupby(key, axis=1)
+   >>> grouped = obj.groupby([key1, key2])
 
 The mapping can be specified many different ways: