DOC: update the Series.str.ismethods docstring (#20913)

Author: MrKriss

pandas/core/strings.py

@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 import numpy as np
 
 from pandas.compat import zip
@@ -2896,12 +2897,144 @@ def rindex(self, sub, start=0, end=None):
                               _shared_docs['swapcase'])
 
     _shared_docs['ismethods'] = ("""
-    Check whether all characters in each string in the Series/Index
-    are %(type)s. Equivalent to :meth:`str.%(method)s`.
+    Check whether all characters in each string are %(type)s.
+
+    This is equivalent to running the Python string method
+    :meth:`str.%(method)s` for each element of the Series/Index. If a string
+    has zero characters, ``False`` is returned for that check.
 
     Returns
     -------
-    is : Series/array of boolean values
+    Series or Index of bool
+        Series or Index of boolean values with the same length as the original
+        Series/Index.
+
+    See Also
+    --------
+    Series.str.isalpha : Check whether all characters are alphabetic.
+    Series.str.isnumeric : Check whether all characters are numeric.
+    Series.str.isalnum : Check whether all characters are alphanumeric.
+    Series.str.isdigit : Check whether all characters are digits.
+    Series.str.isdecimal : Check whether all characters are decimal.
+    Series.str.isspace : Check whether all characters are whitespace.
+    Series.str.islower : Check whether all characters are lowercase.
+    Series.str.isupper : Check whether all characters are uppercase.
+    Series.str.istitle : Check whether all characters are titlecase.
+
+    Examples
+    --------
+    **Checks for Alphabetic and Numeric Characters**
+
+    >>> s1 = pd.Series(['one', 'one1', '1', ''])
+
+    >>> s1.str.isalpha()
+    0     True
+    1    False
+    2    False
+    3    False
+    dtype: bool
+
+    >>> s1.str.isnumeric()
+    0    False
+    1    False
+    2     True
+    3    False
+    dtype: bool
+
+    >>> s1.str.isalnum()
+    0     True
+    1     True
+    2     True
+    3    False
+    dtype: bool
+
+    Note that checks against characters mixed with any additional punctuation
+    or whitespace will evaluate to false for an alphanumeric check.
+
+    >>> s2 = pd.Series(['A B', '1.5', '3,000'])
+    >>> s2.str.isalnum()
+    0    False
+    1    False
+    2    False
+    dtype: bool
+
+    **More Detailed Checks for Numeric Characters**
+
+    There are several different but overlapping sets of numeric characters that
+    can be checked for.
+
+    >>> s3 = pd.Series(['23', '³', '⅕', ''])
+
+    The ``s3.str.isdecimal`` method checks for characters used to form numbers
+    in base 10.
+
+    >>> s3.str.isdecimal()
+    0     True
+    1    False
+    2    False
+    3    False
+    dtype: bool
+
+    The ``s.str.isdigit`` method is the same as ``s3.str.isdecimal`` but also
+    includes special digits, like superscripted and subscripted digits in
+    unicode.
+
+    >>> s3.str.isdigit()
+    0     True
+    1     True
+    2    False
+    3    False
+    dtype: bool
+
+    The ``s.str.isnumeric`` method is the same as ``s3.str.isdigit`` but also
+    includes other characters that can represent quantities such as unicode
+    fractions.
+
+    >>> s3.str.isnumeric()
+    0     True
+    1     True
+    2     True
+    3    False
+    dtype: bool
+
+    **Checks for Whitespace**
+
+    >>> s4 = pd.Series([' ', '\\t\\r\\n ', ''])
+    >>> s4.str.isspace()
+    0     True
+    1     True
+    2    False
+    dtype: bool
+
+    **Checks for Character Case**
+
+    >>> s5 = pd.Series(['leopard', 'Golden Eagle', 'SNAKE', ''])
+
+    >>> s5.str.islower()
+    0     True
+    1    False
+    2    False
+    3    False
+    dtype: bool
+
+    >>> s5.str.isupper()
+    0    False
+    1    False
+    2     True
+    3    False
+    dtype: bool
+
+    The ``s5.str.istitle`` method checks for whether all words are in title
+    case (whether only the first letter of each word is capitalized). Words are
+    assumed to be as any sequence of non-numeric characters seperated by
+    whitespace characters.
+
+    >>> s5.str.istitle()
+    0    False
+    1     True
+    2    False
+    3    False
+    dtype: bool
     """)
     _shared_docs['isalnum'] = dict(type='alphanumeric', method='isalnum')
     _shared_docs['isalpha'] = dict(type='alphabetic', method='isalpha')