DOC: update the pandas.Series.add_suffix docstring (#20315)

Author: astrastefania

pandas/core/generic.py

@@ -2951,7 +2951,8 @@ def add_prefix(self, prefix):
 
         See Also
         --------
-        Series.add_suffix: Suffix labels with string `suffix`.
+        Series.add_suffix: Suffix row labels with string `suffix`.
+        DataFrame.add_suffix: Suffix column labels with string `suffix`.
 
         Examples
         --------
@@ -2990,15 +2991,57 @@ def add_prefix(self, prefix):
 
     def add_suffix(self, suffix):
         """
-        Concatenate suffix string with panel items names.
+        Suffix labels with string `suffix`.
+
+        For Series, the row labels are suffixed.
+        For DataFrame, the column labels are suffixed.
 
         Parameters
         ----------
-        suffix : string
+        suffix : str
+            The string to add after each label.
 
         Returns
         -------
-        with_suffix : type of caller
+        Series or DataFrame
+            New Series or DataFrame with updated labels.
+
+        See Also
+        --------
+        Series.add_prefix: Prefix row labels with string `prefix`.
+        DataFrame.add_prefix: Prefix column labels with string `prefix`.
+
+        Examples
+        --------
+        >>> s = pd.Series([1, 2, 3, 4])
+        >>> s
+        0    1
+        1    2
+        2    3
+        3    4
+        dtype: int64
+
+        >>> s.add_suffix('_item')
+        0_item    1
+        1_item    2
+        2_item    3
+        3_item    4
+        dtype: int64
+
+        >>> df = pd.DataFrame({'A': [1, 2, 3, 4],  'B': [3, 4, 5, 6]})
+        >>> df
+           A  B
+        0  1  3
+        1  2  4
+        2  3  5
+        3  4  6
+
+        >>> df.add_suffix('_col')
+             A_col  B_col
+        0       1       3
+        1       2       4
+        2       3       5
+        3       4       6
         """
         new_data = self._data.add_suffix(suffix)
         return self._constructor(new_data).__finalize__(self)