Create separate section for single level columns.

More clear than lumping all the definitions into a single section at the start.

Author: samuelsinayoko

pandas/core/frame.py

@@ -5195,9 +5195,6 @@ def stack(self, level=-1, dropna=True):
 
         Examples
         --------
-        >>> df_single_level_cols = pd.DataFrame([[0, 1], [2, 3]],
-        ...                                     index=['one', 'two'],
-        ...                                     columns=['a', 'b'])
         >>> multicol1 = pd.MultiIndex.from_tuples([('X', 'a'), ('X', 'b')])
         >>> df_multi_level_cols1 = pd.DataFrame([[0, 1], [2, 3]],
         ...                                    index=['one', 'two'],
@@ -5210,6 +5207,12 @@ def stack(self, level=-1, dropna=True):
         ...                                     index=['one', 'two'],
         ...                                     columns=multicol2)
 
+        **Single level columns**
+
+        >>> df_single_level_cols = pd.DataFrame([[0, 1], [2, 3]],
+        ...                                     index=['one', 'two'],
+        ...                                     columns=['a', 'b'])
+
         Stacking a dataframe with a single level column axis returns a Series:
 
         >>> df_single_level_cols