DOC: Improving the docstring of Series.str.upper and related (#20462)

Author: Hamishpk

pandas/core/strings.py

@@ -2257,11 +2257,68 @@ def rindex(self, sub, start=0, end=None):
 
     _shared_docs['casemethods'] = ("""
     Convert strings in the Series/Index to %(type)s.
+
     Equivalent to :meth:`str.%(method)s`.
 
     Returns
     -------
-    converted : Series/Index of objects
+    Series/Index of objects
+
+    See Also
+    --------
+    Series.str.lower : Converts all characters to lowercase.
+    Series.str.upper : Converts all characters to uppercase.
+    Series.str.title : Converts first character of each word to uppercase and
+        remaining to lowercase.
+    Series.str.capitalize : Converts first character to uppercase and
+        remaining to lowercase.
+    Series.str.swapcase : Converts uppercase to lowercase and lowercase to
+        uppercase.
+
+    Examples
+    --------
+    >>> s = pd.Series(['lower', 'CAPITALS', 'this is a sentence', 'SwApCaSe'])
+    >>> s
+    0                 lower
+    1              CAPITALS
+    2    this is a sentence
+    3              SwApCaSe
+    dtype: object
+
+    >>> s.str.lower()
+    0                 lower
+    1              capitals
+    2    this is a sentence
+    3              swapcase
+    dtype: object
+
+    >>> s.str.upper()
+    0                 LOWER
+    1              CAPITALS
+    2    THIS IS A SENTENCE
+    3              SWAPCASE
+    dtype: object
+
+    >>> s.str.title()
+    0                 Lower
+    1              Capitals
+    2    This Is A Sentence
+    3              Swapcase
+    dtype: object
+
+    >>> s.str.capitalize()
+    0                 Lower
+    1              Capitals
+    2    This is a sentence
+    3              Swapcase
+    dtype: object
+
+    >>> s.str.swapcase()
+    0                 LOWER
+    1              capitals
+    2    THIS IS A SENTENCE
+    3              sWaPcAsE
+    dtype: object
     """)
     _shared_docs['lower'] = dict(type='lowercase', method='lower')
     _shared_docs['upper'] = dict(type='uppercase', method='upper')