DOC: expand doc for numeric_only

Author: chris-b1

pandas/core/generic.py

@@ -5510,8 +5510,8 @@ def _doc_parms(cls):
  If the axis is a MultiIndex (hierarchical), count along a
  particular level, collapsing into a %(name1)s
 numeric_only : boolean, default None
- Include only float, int, boolean data. If None, will attempt to use
- everything, then use only numeric data
+ Include only float, int, boolean columns. If None, will attempt to use
+ everything, then use only numeric data. Not implemented for Series.
 
 Returns
 -------
@@ -5533,8 +5533,8 @@ def _doc_parms(cls):
 ddof : int, default 1
  degrees of freedom
 numeric_only : boolean, default None
- Include only float, int, boolean data. If None, will attempt to use
- everything, then use only numeric data
+ Include only float, int, boolean columns. If None, will attempt to use
+ everything, then use only numeric data. Not implemented for Series.
 
 Returns
 -------
@@ -5554,8 +5554,8 @@ def _doc_parms(cls):
  If the axis is a MultiIndex (hierarchical), count along a
  particular level, collapsing into a %(name1)s
 bool_only : boolean, default None
- Include only boolean data. If None, will attempt to use everything,
- then use only boolean data
+ Include only boolean columns. If None, will attempt to use everything,
+ then use only boolean data. Not implemented for Series.
 
 Returns
 -------