path: root/Lib/test/string_tests.py

"""
Common tests shared by test_unicode, test_userstring and test_bytes.
"""

import unittest, string, sys, struct
from test import support
from collections import UserList
import random

class Sequence:
    def __init__(self, seq='wxyz'): self.seq = seq
    def __len__(self): return len(self.seq)
    def __getitem__(self, i): return self.seq[i]

class BadSeq1(Sequence):
    def __init__(self): self.seq = [7, 'hello', 123]
    def __str__(self): return '{0} {1} {2}'.format(*self.seq)

class BadSeq2(Sequence):
    def __init__(self): self.seq = ['a', 'b', 'c']
    def __len__(self): return 8

class BaseTest:
    # These tests are for buffers of values (bytes) and not
    # specific to character interpretation, used for bytes objects
    # and various string implementations

    # The type to be tested
    # Change in subclasses to change the behaviour of fixtesttype()
    type2test = None

    # Whether the "contained items" of the container are integers in
    # range(0, 256) (i.e. bytes, bytearray) or strings of length 1
    # (str)
    contains_bytes = False

    # All tests pass their arguments to the testing methods
    # as str objects. fixtesttype() can be used to propagate
    # these arguments to the appropriate type
    def fixtype(self, obj):
        if isinstance(obj, str):
            return self.__class__.type2test(obj)
        elif isinstance(obj, list):
            return [self.fixtype(x) for x in obj]
        elif isinstance(obj, tuple):
            return tuple([self.fixtype(x) for x in obj])
        elif isinstance(obj, dict):
            return dict([
               (self.fixtype(key), self.fixtype(value))
               for (key, value) in obj.items()
            ])
        else:
            return obj

    def test_fixtype(self):
        self.assertIs(type(self.fixtype("123")), self.type2test)

    # check that obj.method(*args) returns result
    def checkequal(self, result, obj, methodname, *args, **kwargs):
        result = self.fixtype(result)
        obj = self.fixtype(obj)
        args = self.fixtype(args)
        kwargs = {k: self.fixtype(v) for k,v in kwargs.items()}
        realresult = getattr(obj, methodname)(*args, **kwargs)
        self.assertEqual(
            result,
            realresult
        )
        # if the original is returned make sure that
        # this doesn't happen with subclasses
        if obj is realresult:
            try:
                class subtype(self.__class__.type2test):
                    pass
            except TypeError:
                pass  # Skip this if we can't subclass
            else:
                obj = subtype(obj)
                realresult = getattr(obj, methodname)(*args)
                self.assertIsNot(obj, realresult)

    # check that obj.method(*args) raises exc
    def checkraises(self, exc, obj, methodname, *args, expected_msg=None):
        obj = self.fixtype(obj)
        args = self.fixtype(args)
        with self.assertRaises(exc) as cm:
            getattr(obj, methodname)(*args)
        self.assertNotEqual(str(cm.exception), '')
        if expected_msg is not None:
            self.assertEqual(str(cm.exception), expected_msg)

    # call obj.method(*args) without any checks
    def checkcall(self, obj, methodname, *args):
        obj = self.fixtype(obj)
        args = self.fixtype(args)
        getattr(obj, methodname)(*args)

    def test_count(self):
        self.checkequal(3, 'aaa', 'count', 'a')
        self.checkequal(0, 'aaa', 'count', 'b')
        self.checkequal(3, 'aaa', 'count', 'a')
        self.checkequal(0, 'aaa', 'count', 'b')
        self.checkequal(3, 'aaa', 'count', 'a')
        self.checkequal(0, 'aaa', 'count', 'b')
        self.checkequal(0, 'aaa', 'count', 'b')
        self.checkequal(2, 'aaa', 'count', 'a', 1)
        self.checkequal(0, 'aaa', 'count', 'a', 10)
        self.checkequal(1, 'aaa', 'count', 'a', -1)
        self.checkequal(3, 'aaa', 'count', 'a', -10)
        self.checkequal(1, 'aaa', 'count', 'a', 0, 1)
        self.checkequal(3, 'aaa', 'count', 'a', 0, 10)
        self.checkequal(2, 'aaa', 'count', 'a', 0, -1)
        self.checkequal(0, 'aaa', 'count', 'a', 0, -10)
        self.checkequal(3, 'aaa', 'count', '', 1)
        self.checkequal(1, 'aaa', 'count', '', 3)
        self.checkequal(0, 'aaa', 'count', '', 10)
        self.checkequal(2, 'aaa', 'count', '', -1)
        self.checkequal(4, 'aaa', 'count', '', -10)

        self.checkequal(1, '', 'count', '')
        self.checkequal(0, '', 'count', '', 1, 1)
        self.checkequal(0, '', 'count', '', sys.maxsize, 0)

        self.checkequal(0, '', 'count', 'xx')
        self.checkequal(0, '', 'count', 'xx', 1, 1)
        self.checkequal(0, '', 'count', 'xx', sys.maxsize, 0)

        self.checkraises(TypeError, 'hello', 'count')

        if self.contains_bytes:
            self.checkequal(0, 'hello', 'count', 42)
        else:
            self.checkraises(TypeError, 'hello', 'count', 42)

        # For a variety of combinations,
        #    verify that str.count() matches an equivalent function
        #    replacing all occurrences and then differencing the string lengths
        charset = ['', 'a', 'b']
        digits = 7
        base = len(charset)
        teststrings = set()
        for i in range(base ** digits):
            entry = []
            for j in range(digits):
                i, m = divmod(i, base)
                entry.append(charset[m])
            teststrings.add(''.join(entry))
        teststrings = [self.fixtype(ts) for ts in teststrings]
        for i in teststrings:
            n = len(i)
            for j in teststrings:
                r1 = i.count(j)
                if j:
                    r2, rem = divmod(n - len(i.replace(j, self.fixtype(''))),
                                     len(j))
                else:
                    r2, rem = len(i)+1, 0
                if rem or r1 != r2:
                    self.assertEqual(rem, 0, '%s != 0 for %s' % (rem, i))
                    self.assertEqual(r1, r2, '%s != %s for %s' % (r1, r2, i))

    def test_find(self):
        self.checkequal(0, 'abcdefghiabc', 'find', 'abc')
        self.checkequal(9, 'abcdefghiabc', 'find', 'abc', 1)
        self.checkequal(-1, 'abcdefghiabc', 'find', 'def', 4)

        self.checkequal(0, 'abc', 'find', '', 0)
        self.checkequal(3, 'abc', 'find', '', 3)
        self.checkequal(-1, 'abc', 'find', '', 4)

        # to check the ability to pass None as defaults
        self.checkequal( 2, 'rrarrrrrrrrra', 'find', 'a')
        self.checkequal(12, 'rrarrrrrrrrra', 'find', 'a', 4)
        self.checkequal(-1, 'rrarrrrrrrrra', 'find', 'a', 4, 6)
        self.checkequal(12, 'rrarrrrrrrrra', 'find', 'a', 4, None)
        self.checkequal( 2, 'rrarrrrrrrrra', 'find', 'a', None, 6)

        self.checkraises(TypeError, 'hello', 'find')

        if self.contains_bytes:
            self.checkequal(-1, 'hello', 'find', 42)
        else:
            self.checkraises(TypeError, 'hello', 'find', 42)

        self.checkequal(0, '', 'find', '')
        self.checkequal(-1, '', 'find', '', 1, 1)
        self.checkequal(-1, '', 'find', '', sys.maxsize, 0)

        self.checkequal(-1, '', 'find', 'xx')
        self.checkequal(-1, '', 'find', 'xx', 1, 1)
        self.checkequal(-1, '', 'find', 'xx', sys.maxsize, 0)

        # issue 7458
        self.checkequal(-1, 'ab', 'find', 'xxx', sys.maxsize + 1, 0)

        # For a variety of combinations,
        #    verify that str.find() matches __contains__
        #    and that the found substring is really at that location
        charset = ['', 'a', 'b', 'c']
        digits = 5
        base = len(charset)
        teststrings = set()
        for i in range(base ** digits):
            entry = []
            for j in range(digits):
                i, m = divmod(i, base)
                entry.append(charset[m])
            teststrings.add(''.join(entry))
        teststrings = [self.fixtype(ts) for ts in teststrings]
        for i in teststrings:
            for j in teststrings:
                loc = i.find(j)
                r1 = (loc != -1)
                r2 = j in i
                self.assertEqual(r1, r2)
                if loc != -1:
                    self.assertEqual(i[loc:loc+len(j)], j)

    def test_rfind(self):
        self.checkequal(9,  'abcdefghiabc', 'rfind', 'abc')
        self.checkequal(12, 'abcdefghiabc', 'rfind', '')
        self.checkequal(0, 'abcdefghiabc', 'rfind', 'abcd')
        self.checkequal(-1, 'abcdefghiabc', 'rfind', 'abcz')

        self.checkequal(3, 'abc', 'rfind', '', 0)
        self.checkequal(3, 'abc', 'rfind', '', 3)
        self.checkequal(-1, 'abc', 'rfind', '', 4)

        # to check the ability to pass None as defaults
        self.checkequal(12, 'rrarrrrrrrrra', 'rfind', 'a')
        self.checkequal(12, 'rrarrrrrrrrra', 'rfind', 'a', 4)
        self.checkequal(-1, 'rrarrrrrrrrra', 'rfind', 'a', 4, 6)
        self.checkequal(12, 'rrarrrrrrrrra', 'rfind', 'a', 4, None)
        self.checkequal( 2, 'rrarrrrrrrrra', 'rfind', 'a', None, 6)

        self.checkraises(TypeError, 'hello', 'rfind')

        if self.contains_bytes:
            self.checkequal(-1, 'hello', 'rfind', 42)
        else:
            self.checkraises(TypeError, 'hello', 'rfind', 42)

        # For a variety of combinations,
        #    verify that str.rfind() matches __contains__
        #    and that the found substring is really at that location
        charset = ['', 'a', 'b', 'c']
        digits = 5
        base = len(charset)
        teststrings = set()
        for i in range(base ** digits):
            entry = []
            for j in range(digits):
                i, m = divmod(i, base)
                entry.append(charset[m])
            teststrings.add(''.join(entry))
        teststrings = [self.fixtype(ts) for ts in teststrings]
        for i in teststrings:
            for j in teststrings:
                loc = i.rfind(j)
                r1 = (loc != -1)
                r2 = j in i
                self.assertEqual(r1, r2)
                if loc != -1:
                    self.assertEqual(i[loc:loc+len(j)], j)

        # issue 7458
        self.checkequal(-1, 'ab', 'rfind', 'xxx', sys.maxsize + 1, 0)

        # issue #15534
        self.checkequal(0, '<......\u043c...', "rfind", "<")

    def test_index(self):
        self.checkequal(0, 'abcdefghiabc', 'index', '')
        self.checkequal(3, 'abcdefghiabc', 'index', 'def')
        self.checkequal(0, 'abcdefghiabc', 'index', 'abc')
        self.checkequal(9, 'abcdefghiabc', 'index', 'abc', 1)

        self.checkraises(ValueError, 'abcdefghiabc', 'index', 'hib')
        self.checkraises(ValueError, 'abcdefghiab', 'index', 'abc', 1)
        self.checkraises(ValueError, 'abcdefghi', 'index', 'ghi', 8)
        self.checkraises(ValueError, 'abcdefghi', 'index', 'ghi', -1)

        # to check the ability to pass None as defaults
        self.checkequal( 2, 'rrarrrrrrrrra', 'index', 'a')
        self.checkequal(12, 'rrarrrrrrrrra', 'index', 'a', 4)
        self.checkraises(ValueError, 'rrarrrrrrrrra', 'index', 'a', 4, 6)
        self.checkequal(12, 'rrarrrrrrrrra', 'index', 'a', 4, None)
        self.checkequal( 2, 'rrarrrrrrrrra', 'index', 'a', None, 6)

        self.checkraises(TypeError, 'hello', 'index')

        if self.contains_bytes:
            self.checkraises(ValueError, 'hello', 'index', 42)
        else:
            self.checkraises(TypeError, 'hello', 'index', 42)

    def test_rindex(self):
        self.checkequal(12, 'abcdefghiabc', 'rindex', '')
        self.checkequal(3,  'abcdefghiabc', 'rindex', 'def')
        self.checkequal(9,  'abcdefghiabc', 'rindex', 'abc')
        self.checkequal(0,  'abcdefghiabc', 'rindex', 'abc', 0, -1)

        self.checkraises(ValueError, 'abcdefghiabc', 'rindex', 'hib')
        self.checkraises(ValueError, 'defghiabc', 'rindex', 'def', 1)
        self.checkraises(ValueError, 'defghiabc', 'rindex', 'abc', 0, -1)
        self.checkraises(ValueError, 'abcdefghi', 'rindex', 'ghi', 0, 8)
        self.checkraises(ValueError, 'abcdefghi', 'rindex', 'ghi', 0, -1)

        # to check the ability to pass None as defaults
        self.checkequal(12, 'rrarrrrrrrrra', 'rindex', 'a')
        self.checkequal(12, 'rrarrrrrrrrra', 'rindex', 'a', 4)
        self.checkraises(ValueError, 'rrarrrrrrrrra', 'rindex', 'a', 4, 6)
        self.checkequal(12, 'rrarrrrrrrrra', 'rindex', 'a', 4, None)
        self.checkequal( 2, 'rrarrrrrrrrra', 'rindex', 'a', None, 6)

        self.checkraises(TypeError, 'hello', 'rindex')

        if self.contains_bytes:
            self.checkraises(ValueError, 'hello', 'rindex', 42)
        else:
            self.checkraises(TypeError, 'hello', 'rindex', 42)

    def test_find_periodic_pattern(self):
        """Cover the special path for periodic patterns."""
        def reference_find(p, s):
            for i in range(len(s)):
                if s.startswith(p, i):
                    return i
            return -1

        rr = random.randrange
        choices = random.choices
        for _ in range(1000):
            p0 = ''.join(choices('abcde', k=rr(10))) * rr(10, 20)
            p = p0[:len(p0) - rr(10)] # pop off some characters
            left = ''.join(choices('abcdef', k=rr(2000)))
            right = ''.join(choices('abcdef', k=rr(2000)))
            text = left + p + right
            with self.subTest(p=p, text=text):
                self.checkequal(reference_find(p, text),
                                text, 'find', p)

    def test_find_shift_table_overflow(self):
        """When the table of 8-bit shifts overflows."""
        N = 2**8 + 100

        # first check the periodic case
        # here, the shift for 'b' is N + 1.
        pattern1 = 'a' * N + 'b' + 'a' * N
        text1 = 'babbaa' * N + pattern1
        self.checkequal(len(text1)-len(pattern1),
                        text1, 'find', pattern1)

        # now check the non-periodic case
        # here, the shift for 'd' is 3*(N+1)+1
        pattern2 = 'ddd' + 'abc' * N + "eee"
        text2 = pattern2[:-1] + "ddeede" * 2 * N + pattern2 + "de" * N
        self.checkequal(len(text2) - N*len("de") - len(pattern2),
                        text2, 'find', pattern2)

    def test_lower(self):
        self.checkequal('hello', 'HeLLo', 'lower')
        self.checkequal('hello', 'hello', 'lower')
        self.checkraises(TypeError, 'hello', 'lower', 42)

    def test_upper(self):
        self.checkequal('HELLO', 'HeLLo', 'upper')
        self.checkequal('HELLO', 'HELLO', 'upper')
        self.checkraises(TypeError, 'hello', 'upper', 42)

    def test_expandtabs(self):
        self.checkequal('abc\rab      def\ng       hi', 'abc\rab\tdef\ng\thi',
                        'expandtabs')
        self.checkequal('abc\rab      def\ng       hi', 'abc\rab\tdef\ng\thi',
                        'expandtabs', 8)
        self.checkequal('abc\rab  def\ng   hi', 'abc\rab\tdef\ng\thi',
                        'expandtabs', 4)
        self.checkequal('abc\r\nab      def\ng       hi', 'abc\r\nab\tdef\ng\thi',
                        'expandtabs')
        self.checkequal('abc\r\nab      def\ng       hi', 'abc\r\nab\tdef\ng\thi',
                        'expandtabs', 8)
        self.checkequal('abc\r\nab  def\ng   hi', 'abc\r\nab\tdef\ng\thi',
                        'expandtabs', 4)
        self.checkequal('abc\r\nab\r\ndef\ng\r\nhi', 'abc\r\nab\r\ndef\ng\r\nhi',
                        'expandtabs', 4)
        # check keyword args
        self.checkequal('abc\rab      def\ng       hi', 'abc\rab\tdef\ng\thi',
                        'expandtabs', tabsize=8)
        self.checkequal('abc\rab  def\ng   hi', 'abc\rab\tdef\ng\thi',
                        'expandtabs', tabsize=4)

        self.checkequal('  a\n b', ' \ta\n\tb', 'expandtabs', 1)

        self.checkraises(TypeError, 'hello', 'expandtabs', 42, 42)
        # This test is only valid when sizeof(int) == sizeof(void*) == 4.
        if sys.maxsize < (1 << 32) and struct.calcsize('P') == 4:
            self.checkraises(OverflowError,
                             '\ta\n\tb', 'expandtabs', sys.maxsize)

    def test_split(self):
        # by a char
        self.checkequal(['a', 'b', 'c', 'd'], 'a|b|c|d', 'split', '|')
        self.checkequal(['a|b|c|d'], 'a|b|c|d', 'split', '|', 0)
        self.checkequal(['a', 'b|c|d'], 'a|b|c|d', 'split', '|', 1)
        self.checkequal(['a', 'b', 'c|d'], 'a|b|c|d', 'split', '|', 2)
        self.checkequal(['a', 'b', 'c', 'd'], 'a|b|c|d', 'split', '|', 3)
        self.checkequal(['a', 'b', 'c', 'd'], 'a|b|c|d', 'split', '|', 4)
        self.checkequal(['a', 'b', 'c', 'd'], 'a|b|c|d', 'split', '|',
                        sys.maxsize-2)
        self.checkequal(['a|b|c|d'], 'a|b|c|d', 'split', '|', 0)
        self.checkequal(['a', '', 'b||c||d'], 'a||b||c||d', 'split', '|', 2)
        self.checkequal(['abcd'], 'abcd', 'split', '|')
        self.checkequal([''], '', 'split', '|')
        self.checkequal(['endcase ', ''], 'endcase |', 'split', '|')
        self.checkequal(['', ' startcase'], '| startcase', 'split', '|')
        self.checkequal(['', 'bothcase', ''], '|bothcase|', 'split', '|')
        self.checkequal(['a', '', 'b\x00c\x00d'], 'a\x00\x00b\x00c\x00d', 'split', '\x00', 2)

        self.checkequal(['a']*20, ('a|'*20)[:-1], 'split', '|')
        self.checkequal(['a']*15 +['a|a|a|a|a'],
                                   ('a|'*20)[:-1], 'split', '|', 15)

        # by string
        self.checkequal(['a', 'b', 'c', 'd'], 'a//b//c//d', 'split', '//')
        self.checkequal(['a', 'b//c//d'], 'a//b//c//d', 'split', '//', 1)
        self.checkequal(['a', 'b', 'c//d'], 'a//b//c//d', 'split', '//', 2)
        self.checkequal(['a', 'b', 'c', 'd'], 'a//b//c//d', 'split', '//', 3)
        self.checkequal(['a', 'b', 'c', 'd'], 'a//b//c//d', 'split', '//', 4)
        self.checkequal(['a', 'b', 'c', 'd'], 'a//b//c//d', 'split', '//',
                        sys.maxsize-10)
        self.checkequal(['a//b//c//d'], 'a//b//c//d', 'split', '//', 0)
        self.checkequal(['a', '', 'b////c////d'], 'a////b////c////d', 'split', '//', 2)
        self.checkequal(['endcase ', ''], 'endcase test', 'split', 'test')
        self.checkequal(['', ' begincase'], 'test begincase', 'split', 'test')
        self.checkequal(['', ' bothcase ', ''], 'test bothcase test',
                        'split', 'test')
        self.checkequal(['a', 'bc'], 'abbbc', 'split', 'bb')
        self.checkequal(['', ''], 'aaa', 'split', 'aaa')
        self.checkequal(['aaa'], 'aaa', 'split', 'aaa', 0)
        self.checkequal(['ab', 'ab'], 'abbaab', 'split', 'ba')
        self.checkequal(['aaaa'], 'aaaa', 'split', 'aab')
        self.checkequal([''], '', 'split', 'aaa')
        self.checkequal(['aa'], 'aa', 'split', 'aaa')
        self.checkequal(['A', 'bobb'], 'Abbobbbobb', 'split', 'bbobb')
        self.checkequal(['A', 'B', ''], 'AbbobbBbbobb', 'split', 'bbobb')

        self.checkequal(['a']*20, ('aBLAH'*20)[:-4], 'split', 'BLAH')
        self.checkequal(['a']*20, ('aBLAH'*20)[:-4], 'split', 'BLAH', 19)
        self.checkequal(['a']*18 + ['aBLAHa'], ('aBLAH'*20)[:-4],
                        'split', 'BLAH', 18)

        # with keyword args
        self.checkequal(['a', 'b', 'c', 'd'], 'a|b|c|d', 'split', sep='|')
        self.checkequal(['a', 'b|c|d'],
                        'a|b|c|d', 'split', '|', maxsplit=1)
        self.checkequal(['a', 'b|c|d'],
                        'a|b|c|d', 'split', sep='|', maxsplit=1)
        self.checkequal(['a', 'b|c|d'],
                        'a|b|c|d', 'split', maxsplit=1, sep='|')
        self.checkequal(['a', 'b c d'],
                        'a b c d', 'split', maxsplit=1)

        # argument type
        self.checkraises(TypeError, 'hello', 'split', 42, 42, 42)

        # null case
        self.checkraises(ValueError, 'hello', 'split', '')
        self.checkraises(ValueError, 'hello', 'split', '', 0)

    def test_rsplit(self):
        # by a char
        self.checkequal(['a', 'b', 'c', 'd'], 'a|b|c|d', 'rsplit', '|')
        self.checkequal(['a|b|c', 'd'], 'a|b|c|d', 'rsplit', '|', 1)
        self.checkequal(['a|b', 'c', 'd'], 'a|b|c|d', 'rsplit', '|', 2)
        self.checkequal(['a', 'b', 'c', 'd'], 'a|b|c|d', 'rsplit', '|', 3)
        self.checkequal(['a', 'b', 'c', 'd'], 'a|b|c|d', 'rsplit', '|', 4)
        self.checkequal(['a', 'b', 'c', 'd'], 'a|b|c|d', 'rsplit', '|',
                        sys.maxsize-100)
        self.checkequal(['a|b|c|d'], 'a|b|c|d', 'rsplit', '|', 0)
        self.checkequal(['a||b||c', '', 'd'], 'a||b||c||d', 'rsplit', '|', 2)
        self.checkequal(['abcd'], 'abcd', 'rsplit', '|')
        self.checkequal([''], '', 'rsplit', '|')
        self.checkequal(['', ' begincase'], '| begincase', 'rsplit', '|')
        self.checkequal(['endcase ', ''], 'endcase |', 'rsplit', '|')
        self.checkequal(['', 'bothcase', ''], '|bothcase|', 'rsplit', '|')

        self.checkequal(['a\x00\x00b', 'c', 'd'], 'a\x00\x00b\x00c\x00d', 'rsplit', '\x00', 2)

        self.checkequal(['a']*20, ('a|'*20)[:-1], 'rsplit', '|')
        self.checkequal(['a|a|a|a|a']+['a']*15,
                        ('a|'*20)[:-1], 'rsplit', '|', 15)

        # by string
        self.checkequal(['a', 'b', 'c', 'd'], 'a//b//c//d', 'rsplit', '//')
        self.checkequal(['a//b//c', 'd'], 'a//b//c//d', 'rsplit', '//', 1)
        self.checkequal(['a//b', 'c', 'd'], 'a//b//c//d', 'rsplit', '//', 2)
        self.checkequal(['a', 'b', 'c', 'd'], 'a//b//c//d', 'rsplit', '//', 3)
        self.checkequal(['a', 'b', 'c', 'd'], 'a//b//c//d', 'rsplit', '//', 4)
        self.checkequal(['a', 'b', 'c', 'd'], 'a//b//c//d', 'rsplit', '//',
                        sys.maxsize-5)
        self.checkequal(['a//b//c//d'], 'a//b//c//d', 'rsplit', '//', 0)
        self.checkequal(['a////b////c', '', 'd'], 'a////b////c////d', 'rsplit', '//', 2)
        self.checkequal(['', ' begincase'], 'test begincase', 'rsplit', 'test')
        self.checkequal(['endcase ', ''], 'endcase test', 'rsplit', 'test')
        self.checkequal(['', ' bothcase ', ''], 'test bothcase test',
                        'rsplit', 'test')
        self.checkequal(['ab', 'c'], 'abbbc', 'rsplit', 'bb')
        self.checkequal(['', ''], 'aaa', 'rsplit', 'aaa')
        self.checkequal(['aaa'], 'aaa', 'rsplit', 'aaa', 0)
        self.checkequal(['ab', 'ab'], 'abbaab', 'rsplit', 'ba')
        self.checkequal(['aaaa'], 'aaaa', 'rsplit', 'aab')
        self.checkequal([''], '', 'rsplit', 'aaa')
        self.checkequal(['aa'], 'aa', 'rsplit', 'aaa')
        self.checkequal(['bbob', 'A'], 'bbobbbobbA', 'rsplit', 'bbobb')
        self.checkequal(['', 'B', 'A'], 'bbobbBbbobbA', 'rsplit', 'bbobb')

        self.checkequal(['a']*20, ('aBLAH'*20)[:-4], 'rsplit', 'BLAH')
        self.checkequal(['a']*20, ('aBLAH'*20)[:-4], 'rsplit', 'BLAH', 19)
        self.checkequal(['aBLAHa'] + ['a']*18, ('aBLAH'*20)[:-4],
                        'rsplit', 'BLAH', 18)

        # with keyword args
        self.checkequal(['a', 'b', 'c', 'd'], 'a|b|c|d', 'rsplit', sep='|')
        self.checkequal(['a|b|c', 'd'],
                        'a|b|c|d', 'rsplit', '|', maxsplit=1)
        self.checkequal(['a|b|c', 'd'],
                        'a|b|c|d', 'rsplit', sep='|', maxsplit=1)
        self.checkequal(['a|b|c', 'd'],
                        'a|b|c|d', 'rsplit', maxsplit=1, sep='|')
        self.checkequal(['a b c', 'd'],
                        'a b c d', 'rsplit', maxsplit=1)

        # argument type
        self.checkraises(TypeError, 'hello', 'rsplit', 42, 42, 42)

        # null case
        self.checkraises(ValueError, 'hello', 'rsplit', '')
        self.checkraises(ValueError, 'hello', 'rsplit', '', 0)

    def test_replace(self):
        EQ = self.checkequal

        # Operations on the empty string
        EQ("", "", "replace", "", "")
        EQ("A", "", "replace", "", "A")
        EQ("", "", "replace", "A", "")
        EQ("", "", "replace", "A", "A")
        EQ("", "", "replace", "", "", 100)
        EQ("A", "", "replace", "", "A", 100)
        EQ("", "", "replace", "", "", sys.maxsize)

        # interleave (from=="", 'to' gets inserted everywhere)
        EQ("A", "A", "replace", "", "")
        EQ("*A*", "A", "replace", "", "*")
        EQ("*1A*1", "A", "replace", "", "*1")
        EQ("*-#A*-#", "A", "replace", "", "*-#")
        EQ("*-A*-A*-", "AA", "replace", "", "*-")
        EQ("*-A*-A*-", "AA", "replace", "", "*-", -1)
        EQ("*-A*-A*-", "AA", "replace", "", "*-", sys.maxsize)
        EQ("*-A*-A*-", "AA", "replace", "", "*-", 4)
        EQ("*-A*-A*-", "AA", "replace", "", "*-", 3)
        EQ("*-A*-A", "AA", "replace", "", "*-", 2)
        EQ("*-AA", "AA", "replace", "", "*-", 1)
        EQ("AA", "AA", "replace", "", "*-", 0)

        # single character deletion (from=="A", to=="")
        EQ("", "A", "replace", "A", "")
        EQ("", "AAA", "replace", "A", "")
        EQ("", "AAA", "replace", "A", "", -1)
        EQ("", "AAA", "replace", "A", "", sys.maxsize)
        EQ("", "AAA", "replace", "A", "", 4)
        EQ("", "AAA", "replace", "A", "", 3)
        EQ("A", "AAA", "replace", "A", "", 2)
        EQ("AA", "AAA", "replace", "A", "", 1)
        EQ("AAA", "AAA", "replace", "A", "", 0)
        EQ("", "AAAAAAAAAA", "replace", "A", "")
        EQ("BCD", "ABACADA", "replace", "A", "")
        EQ("BCD", "ABACADA", "replace", "A", "", -1)
        EQ("BCD", "ABACADA", "replace", "A", "", sys.maxsize)
        EQ("BCD", "ABACADA", "replace", "A", "", 5)
        EQ("BCD", "ABACADA", "replace", "A", "", 4)
        EQ("BCDA", "ABACADA", "replace", "A", "", 3)
        EQ("BCADA", "ABACADA", "replace", "A", "", 2)
        EQ("BACADA", "ABACADA", "replace", "A", "", 1)
        EQ("ABACADA", "ABACADA", "replace", "A", "", 0)
        EQ("BCD", "ABCAD", "replace", "A", "")
        EQ("BCD", "ABCADAA", "replace", "A", "")
        EQ("BCD", "BCD", "replace", "A", "")
        EQ("*************", "*************", "replace", "A", "")
        EQ("^A^", "^"+"A"*1000+"^", "replace", "A", "", 999)

        # substring deletion (from=="the", to=="")
        EQ("", "the", "replace", "the", "")
        EQ("ater", "theater", "replace", "the", "")
        EQ("", "thethe", "replace", "the", "")
        EQ("", "thethethethe", "replace", "the", "")
        EQ("aaaa", "theatheatheathea", "replace", "the", "")
        EQ("that", "that", "replace", "the", "")
        EQ("thaet", "thaet", "replace", "the", "")
        EQ("here and re", "here and there", "replace", "the", "")
        EQ("here and re and re", "here and there and there",
           "replace", "the", "", sys.maxsize)
        EQ("here and re and re", "here and there and there",
           "replace", "the", "", -1)
        EQ("here and re and re", "here and there and there",
           "replace", "the", "", 3)
        EQ("here and re and re", "here and there and there",
           "replace", "the", "", 2)
        EQ("here and re and there", "here and there and there",
           "replace", "the", "", 1)
        EQ("here and there and there", "here and there and there",
           "replace", "the", "", 0)
        EQ("here and re and re", "here and there and there", "replace", "the", "")

        EQ("abc", "abc", "replace", "the", "")
        EQ("abcdefg", "abcdefg", "replace", "the", "")

        # substring deletion (from=="bob", to=="")
        EQ("bob", "bbobob", "replace", "bob", "")
        EQ("bobXbob", "bbobobXbbobob", "replace", "bob", "")
        EQ("aaaaaaa", "aaaaaaabob", "replace", "bob", "")
        EQ("aaaaaaa", "aaaaaaa", "replace", "bob", "")

        # single character replace in place (len(from)==len(to)==1)
        EQ("Who goes there?", "Who goes there?", "replace", "o", "o")
        EQ("WhO gOes there?", "Who goes there?", "replace", "o", "O")
        EQ("WhO gOes there?", "Who goes there?", "replace", "o", "O", sys.maxsize)
        EQ("WhO gOes there?", "Who goes there?", "replace", "o", "O", -1)
        EQ("WhO gOes there?", "Who goes there?", "replace", "o", "O", 3)
        EQ("WhO gOes there?", "Who goes there?", "replace", "o", "O", 2)
        EQ("WhO goes there?", "Who goes there?", "replace", "o", "O", 1)
        EQ("Who goes there?", "Who goes there?", "replace", "o", "O", 0)

        EQ("Who goes there?", "Who goes there?", "replace", "a", "q")
        EQ("who goes there?", "Who goes there?", "replace", "W", "w")
        EQ("wwho goes there?ww", "WWho goes there?WW", "replace", "W", "w")
        EQ("Who goes there!", "Who goes there?", "replace", "?", "!")
        EQ("Who goes there!!", "Who goes there??", "replace", "?", "!")

        EQ("Who goes there?", "Who goes there?", "replace", ".", "!")

        # substring replace in place (len(from)==len(to) > 1)
        EQ("Th** ** a t**sue", "This is a tissue", "replace", "is", "**")
        EQ("Th** ** a t**sue", "This is a tissue", "replace", "is", "**", sys.maxsize)
        EQ("Th** ** a t**sue", "This is a tissue", "replace", "is", "**", -1)
        EQ("Th** ** a t**sue", "This is a tissue", "replace", "is", "**", 4)
        EQ("Th** ** a t**sue", "This is a tissue", "replace", "is", "**", 3)
        EQ("Th** ** a tissue", "This is a tissue", "replace", "is", "**", 2)
        EQ("Th** is a tissue", "This is a tissue", "replace", "is", "**", 1)
        EQ("This is a tissue", "This is a tissue", "replace", "is", "**", 0)
        EQ("cobob", "bobob", "replace", "bob", "cob")
        EQ("cobobXcobocob", "bobobXbobobob", "replace", "bob", "cob")
        EQ("bobob", "bobob", "replace", "bot", "bot")

        # replace single character (len(from)==1, len(to)>1)
        EQ("ReyKKjaviKK", "Reykjavik", "replace", "k", "KK")
        EQ("ReyKKjaviKK", "Reykjavik", "replace", "k", "KK", -1)
        EQ("ReyKKjaviKK", "Reykjavik", "replace", "k", "KK", sys.maxsize)
        EQ("ReyKKjaviKK", "Reykjavik", "replace", "k", "KK", 2)
        EQ("ReyKKjavik", "Reykjavik", "replace", "k", "KK", 1)
        EQ("Reykjavik", "Reykjavik", "replace", "k", "KK", 0)
        EQ("A----B----C----", "A.B.C.", "replace", ".", "----")
        # issue #15534
        EQ('...\u043c......&lt;', '...\u043c......<', "replace", "<", "&lt;")

        EQ("Reykjavik", "Reykjavik", "replace", "q", "KK")

        # replace substring (len(from)>1, len(to)!=len(from))
        EQ("ham, ham, eggs and ham", "spam, spam, eggs and spam",
           "replace", "spam", "ham")
        EQ("ham, ham, eggs and ham", "spam, spam, eggs and spam",
           "replace", "spam", "ham", sys.maxsize)
        EQ("ham, ham, eggs and ham", "spam, spam, eggs and spam",
           "replace", "spam", "ham", -1)
        EQ("ham, ham, eggs and ham", "spam, spam, eggs and spam",
           "replace", "spam", "ham", 4)
        EQ("ham, ham, eggs and ham", "spam, spam, eggs and spam",
           "replace", "spam", "ham", 3)
        EQ("ham, ham, eggs and spam", "spam, spam, eggs and spam",
           "replace", "spam", "ham", 2)
        EQ("ham, spam, eggs and spam", "spam, spam, eggs and spam",
           "replace", "spam", "ham", 1)
        EQ("spam, spam, eggs and spam", "spam, spam, eggs and spam",
           "replace", "spam", "ham", 0)

        EQ("bobob", "bobobob", "replace", "bobob", "bob")
        EQ("bobobXbobob", "bobobobXbobobob", "replace", "bobob", "bob")
        EQ("BOBOBOB", "BOBOBOB", "replace", "bob", "bobby")

        self.checkequal('one@two!three!', 'one!two!three!', 'replace', '!', '@', 1)
        self.checkequal('onetwothree', 'one!two!three!', 'replace', '!', '')
        self.checkequal('one@two@three!', 'one!two!three!', 'replace', '!', '@', 2)
        self.checkequal('one@two@three@', 'one!two!three!', 'replace', '!', '@', 3)
        self.checkequal('one@two@three@', 'one!two!three!', 'replace', '!', '@', 4)
        self.checkequal('one!two!three!', 'one!two!three!', 'replace', '!', '@', 0)
        self.checkequal('one@two@three@', 'one!two!three!', 'replace', '!', '@')
        self.checkequal('one!two!three!', 'one!two!three!', 'replace', 'x', '@')
        self.checkequal('one!two!three!', 'one!two!three!', 'replace', 'x', '@', 2)
        self.checkequal('-a-b-c-', 'abc', 'replace', '', '-')
        self.checkequal('-a-b-c', 'abc', 'replace', '', '-', 3)
        self.checkequal('abc', 'abc', 'replace', '', '-', 0)
        self.checkequal('', '', 'replace', '', '')
        self.checkequal('abc', 'abc', 'replace', 'ab', '--', 0)
        self.checkequal('abc', 'abc', 'replace', 'xy', '--')
        # Next three for SF bug 422088: [OSF1 alpha] string.replace(); died with
        # MemoryError due to empty result (platform malloc issue when requesting
        # 0 bytes).
        self.checkequal('', '123', 'replace', '123', '')
        self.checkequal('', '123123', 'replace', '123', '')
        self.checkequal('x', '123x123', 'replace', '123', '')

        self.checkraises(TypeError, 'hello', 'replace')
        self.checkraises(TypeError, 'hello', 'replace', 42)
        self.checkraises(TypeError, 'hello', 'replace', 42, 'h')
        self.checkraises(TypeError, 'hello', 'replace', 'h', 42)

    @unittest.skipIf(sys.maxsize > (1 << 32) or struct.calcsize('P') != 4,
                     'only applies to 32-bit platforms')
    def test_replace_overflow(self):
        # Check for overflow checking on 32 bit machines
        A2_16 = "A" * (2**16)
        self.checkraises(OverflowError, A2_16, "replace", "", A2_16)
        self.checkraises(OverflowError, A2_16, "replace", "A", A2_16)
        self.checkraises(OverflowError, A2_16, "replace", "AA", A2_16+A2_16)

    def test_removeprefix(self):
        self.checkequal('am', 'spam', 'removeprefix', 'sp')
        self.checkequal('spamspam', 'spamspamspam', 'removeprefix', 'spam')
        self.checkequal('spam', 'spam', 'removeprefix', 'python')
        self.checkequal('spam', 'spam', 'removeprefix', 'spider')
        self.checkequal('spam', 'spam', 'removeprefix', 'spam and eggs')

        self.checkequal('', '', 'removeprefix', '')
        self.checkequal('', '', 'removeprefix', 'abcde')
        self.checkequal('abcde', 'abcde', 'removeprefix', '')
        self.checkequal('', 'abcde', 'removeprefix', 'abcde')

        self.checkraises(TypeError, 'hello', 'removeprefix')
        self.checkraises(TypeError, 'hello', 'removeprefix', 42)
        self.checkraises(TypeError, 'hello', 'removeprefix', 42, 'h')
        self.checkraises(TypeError, 'hello', 'removeprefix', 'h', 42)
        self.checkraises(TypeError, 'hello', 'removeprefix', ("he", "l"))

    def test_removesuffix(self):
        self.checkequal('sp', 'spam', 'removesuffix', 'am')
        self.checkequal('spamspam', 'spamspamspam', 'removesuffix', 'spam')
        self.checkequal('spam', 'spam', 'removesuffix', 'python')
        self.checkequal('spam', 'spam', 'removesuffix', 'blam')
        self.checkequal('spam', 'spam', 'removesuffix', 'eggs and spam')

        self.checkequal('', '', 'removesuffix', '')
        self.checkequal('', '', 'removesuffix', 'abcde')
        self.checkequal('abcde', 'abcde', 'removesuffix', '')
        self.checkequal('', 'abcde', 'removesuffix', 'abcde')

        self.checkraises(TypeError, 'hello', 'removesuffix')
        self.checkraises(TypeError, 'hello', 'removesuffix', 42)
        self.checkraises(TypeError, 'hello', 'removesuffix', 42, 'h')
        self.checkraises(TypeError, 'hello', 'removesuffix', 'h', 42)
        self.checkraises(TypeError, 'hello', 'removesuffix', ("lo", "l"))

    def test_capitalize(self):
        self.checkequal(' hello ', ' hello ', 'capitalize')
        self.checkequal('Hello ', 'Hello ','capitalize')
        self.checkequal('Hello ', 'hello ','capitalize')
        self.checkequal('Aaaa', 'aaaa', 'capitalize')
        self.checkequal('Aaaa', 'AaAa', 'capitalize')

        self.checkraises(TypeError, 'hello', 'capitalize', 42)

    def test_additional_split(self):
        self.checkequal(['this', 'is', 'the', 'split', 'function'],
            'this is the split function', 'split')

        # by whitespace
        self.checkequal(['a', 'b', 'c', 'd'], 'a b c d ', 'split')
        self.checkequal(['a', 'b c d'], 'a b c d', 'split', None, 1)
        self.checkequal(['a', 'b', 'c d'], 'a b c d', 'split', None, 2)
        self.checkequal(['a', 'b', 'c', 'd'], 'a b c d', 'split', None, 3)
        self.checkequal(['a', 'b', 'c', 'd'], 'a b c d', 'split', None, 4)
        self.checkequal(['a', 'b', 'c', 'd'], 'a b c d', 'split', None,
                        sys.maxsize-1)
        self.checkequal(['a b c d'], 'a b c d', 'split', None, 0)
        self.checkequal(['a b c d'], '  a b c d', 'split', None, 0)
        self.checkequal(['a', 'b', 'c  d'], 'a  b  c  d', 'split', None, 2)

        self.checkequal([], '         ', 'split')
        self.checkequal(['a'], '  a    ', 'split')
        self.checkequal(['a', 'b'], '  a    b   ', 'split')
        self.checkequal(['a', 'b   '], '  a    b   ', 'split', None, 1)
        self.checkequal(['a    b   c   '], '  a    b   c   ', 'split', None, 0)
        self.checkequal(['a', 'b   c   '], '  a    b   c   ', 'split', None, 1)
        self.checkequal(['a', 'b', 'c   '], '  a    b   c   ', 'split', None, 2)
        self.checkequal(['a', 'b', 'c'], '  a    b   c   ', 'split', None, 3)
        self.checkequal(['a', 'b'], '\n\ta \t\r b \v ', 'split')
        aaa = ' a '*20
        self.checkequal(['a']*20, aaa, 'split')
        self.checkequal(['a'] + [aaa[4:]], aaa, 'split', None, 1)
        self.checkequal(['a']*19 + ['a '], aaa, 'split', None, 19)

        for b in ('arf\tbarf', 'arf\nbarf', 'arf\rbarf',
                  'arf\fbarf', 'arf\vbarf'):
            self.checkequal(['arf', 'barf'], b, 'split')
            self.checkequal(['arf', 'barf'], b, 'split', None)
            self.checkequal(['arf', 'barf'], b, 'split', None, 2)

    def test_additional_rsplit(self):
        self.checkequal(['this', 'is', 'the', 'rsplit', 'function'],
                         'this is the rsplit function', 'rsplit')

        # by whitespace
        self.checkequal(['a', 'b', 'c', 'd'], 'a b c d ', 'rsplit')
        self.checkequal(['a b c', 'd'], 'a b c d', 'rsplit', None, 1)
        self.checkequal(['a b', 'c', 'd'], 'a b c d', 'rsplit', None, 2)
        self.checkequal(['a', 'b', 'c', 'd'], 'a b c d', 'rsplit', None, 3)
        self.checkequal(['a', 'b', 'c', 'd'], 'a b c d', 'rsplit', None, 4)
        self.checkequal(['a', 'b', 'c', 'd'], 'a b c d', 'rsplit', None,
                        sys.maxsize-20)
        self.checkequal(['a b c d'], 'a b c d', 'rsplit', None, 0)
        self.checkequal(['a b c d'], 'a b c d  ', 'rsplit', None, 0)
        self.checkequal(['a  b', 'c', 'd'], 'a  b  c  d', 'rsplit', None, 2)

        self.checkequal([], '         ', 'rsplit')
        self.checkequal(['a'], '  a    ', 'rsplit')
        self.checkequal(['a', 'b'], '  a    b   ', 'rsplit')
        self.checkequal(['  a', 'b'], '  a    b   ', 'rsplit', None, 1)
        self.checkequal(['  a    b   c'], '  a    b   c   ', 'rsplit',
                        None, 0)
        self.checkequal(['  a    b','c'], '  a    b   c   ', 'rsplit',
                        None, 1)
        self.checkequal(['  a', 'b', 'c'], '  a    b   c   ', 'rsplit',
                        None, 2)
        self.checkequal(['a', 'b', 'c'], '  a    b   c   ', 'rsplit',
                        None, 3)
        self.checkequal(['a', 'b'], '\n\ta \t\r b \v ', 'rsplit', None, 88)
        aaa = ' a '*20
        self.checkequal(['a']*20, aaa, 'rsplit')
        self.checkequal([aaa[:-4]] + ['a'], aaa, 'rsplit', None, 1)
        self.checkequal([' a  a'] + ['a']*18, aaa, 'rsplit', None, 18)

        for b in ('arf\tbarf', 'arf\nbarf', 'arf\rbarf',
                  'arf\fbarf', 'arf\vbarf'):
            self.checkequal(['arf', 'barf'], b, 'rsplit')
            self.checkequal(['arf', 'barf'], b, 'rsplit', None)
            self.checkequal(['arf', 'barf'], b, 'rsplit', None, 2)

    def test_strip_whitespace(self):
        self.checkequal('hello', '   hello   ', 'strip')
        self.checkequal('hello   ', '   hello   ', 'lstrip')
        self.checkequal('   hello', '   hello   ', 'rstrip')
        self.checkequal('hello', 'hello', 'strip')

        b = ' \t\n\r\f\vabc \t\n\r\f\v'
        self.checkequal('abc', b, 'strip')
        self.checkequal('abc \t\n\r\f\v', b, 'lstrip')
        self.checkequal(' \t\n\r\f\vabc', b, 'rstrip')

        # strip/lstrip/rstrip with None arg
        self.checkequal('hello', '   hello   ', 'strip', None)
        self.checkequal('hello   ', '   hello   ', 'lstrip', None)
        self.checkequal('   hello', '   hello   ', 'rstrip', None)
        self.checkequal('hello', 'hello', 'strip', None)

    def test_strip(self):
        # strip/lstrip/rstrip with str arg
        self.checkequal('hello', 'xyzzyhelloxyzzy', 'strip', 'xyz')
        self.checkequal('helloxyzzy', 'xyzzyhelloxyzzy', 'lstrip', 'xyz')
        self.checkequal('xyzzyhello', 'xyzzyhelloxyzzy', 'rstrip', 'xyz')
        self.checkequal('hello', 'hello', 'strip', 'xyz')
        self.checkequal('', 'mississippi', 'strip', 'mississippi')

        # only trim the start and end; does not strip internal characters
        self.checkequal('mississipp', 'mississippi', 'strip', 'i')

        self.checkraises(TypeError, 'hello', 'strip', 42, 42)
        self.checkraises(TypeError, 'hello', 'lstrip', 42, 42)
        self.checkraises(TypeError, 'hello', 'rstrip', 42, 42)

    def test_ljust(self):
        self.checkequal('abc       ', 'abc', 'ljust', 10)
        self.checkequal('abc   ', 'abc', 'ljust', 6)
        self.checkequal('abc', 'abc', 'ljust', 3)
        self.checkequal('abc', 'abc', 'ljust', 2)
        self.checkequal('abc*******', 'abc', 'ljust', 10, '*')
        self.checkraises(TypeError, 'abc', 'ljust')

    def test_rjust(self):
        self.checkequal('       abc', 'abc', 'rjust', 10)
        self.checkequal('   abc', 'abc', 'rjust', 6)
        self.checkequal('abc', 'abc', 'rjust', 3)
        self.checkequal('abc', 'abc', 'rjust', 2)
        self.checkequal('*******abc', 'abc', 'rjust', 10, '*')
        self.checkraises(TypeError, 'abc', 'rjust')

    def test_center(self):
        self.checkequal('   abc    ', 'abc', 'center', 10)
        self.checkequal(' abc  ', 'abc', 'center', 6)
        self.checkequal('abc', 'abc', 'center', 3)
        self.checkequal('abc', 'abc', 'center', 2)
        self.checkequal('***abc****', 'abc', 'center', 10, '*')
        self.checkraises(TypeError, 'abc', 'center')

    def test_swapcase(self):
        self.checkequal('hEllO CoMPuTErS', 'HeLLo cOmpUteRs', 'swapcase')

        self.checkraises(TypeError, 'hello', 'swapcase', 42)

    def test_zfill(self):
        self.checkequal('123', '123', 'zfill', 2)
        self.checkequal('123', '123', 'zfill', 3)
        self.checkequal('0123', '123', 'zfill', 4)
        self.checkequal('+123', '+123', 'zfill', 3)
        self.checkequal('+123', '+123', 'zfill', 4)
        self.checkequal('+0123', '+123', 'zfill', 5)
        self.checkequal('-123', '-123', 'zfill', 3)
        self.checkequal('-123', '-123', 'zfill', 4)
        self.checkequal('-0123', '-123', 'zfill', 5)
        self.checkequal('000', '', 'zfill', 3)
        self.checkequal('34', '34', 'zfill', 1)
        self.checkequal('0034', '34', 'zfill', 4)

        self.checkraises(TypeError, '123', 'zfill')

    def test_islower(self):
        self.checkequal(False, '', 'islower')
        self.checkequal(True, 'a', 'islower')
        self.checkequal(False, 'A', 'islower')
        self.checkequal(False, '\n', 'islower')
        self.checkequal(True, 'abc', 'islower')
        self.checkequal(False, 'aBc', 'islower')
        self.checkequal(True, 'abc\n', 'islower')
        self.checkraises(TypeError, 'abc', 'islower', 42)

    def test_isupper(self):
        self.checkequal(False, '', 'isupper')
        self.checkequal(False, 'a', 'isupper')
        self.checkequal(True, 'A', 'isupper')
        self.checkequal(False, '\n', 'isupper')
        self.checkequal(True, 'ABC', 'isupper')
        self.checkequal(False, 'AbC', 'isupper')
        self.checkequal(True, 'ABC\n', 'isupper')
        self.checkraises(TypeError, 'abc', 'isupper', 42)

    def test_istitle(self):
        self.checkequal(False, '', 'istitle')
        self.checkequal(False, 'a', 'istitle')
        self.checkequal(True, 'A', 'istitle')
        self.checkequal(False, '\n', 'istitle')
        self.checkequal(True, 'A Titlecased Line', 'istitle')
        self.checkequal(True, 'A\nTitlecased Line', 'istitle')
        self.checkequal(True, 'A Titlecased, Line', 'istitle')
        self.checkequal(False, 'Not a capitalized String', 'istitle')
        self.checkequal(False, 'Not\ta Titlecase String', 'istitle')
        self.checkequal(False, 'Not--a Titlecase String', 'istitle')
        self.checkequal(False, 'NOT', 'istitle')
        self.checkraises(TypeError, 'abc', 'istitle', 42)

    def test_isspace(self):
        self.checkequal(False, '', 'isspace')
        self.checkequal(False, 'a', 'isspace')
        self.checkequal(True, ' ', 'isspace')
        self.checkequal(True, '\t', 'isspace')
        self.checkequal(True, '\r', 'isspace')
        self.checkequal(True, '\n', 'isspace')
        self.checkequal(True, ' \t\r\n', 'isspace')
        self.checkequal(False, ' \t\r\na', 'isspace')
        self.checkraises(TypeError, 'abc', 'isspace', 42)

    def test_isalpha(self):
        self.checkequal(False, '', 'isalpha')
        self.checkequal(True, 'a', 'isalpha')
        self.checkequal(True, 'A', 'isalpha')
        self.checkequal(False, '\n', 'isalpha')
        self.checkequal(True, 'abc', 'isalpha')
        self.checkequal(False, 'aBc123', 'isalpha')
        self.checkequal(False, 'abc\n', 'isalpha')
        self.checkraises(TypeError, 'abc', 'isalpha', 42)

    def test_isalnum(self):
        self.checkequal(False, '', 'isalnum')
        self.checkequal(True, 'a', 'isalnum')
        self.checkequal(True, 'A', 'isalnum')
        self.checkequal(False, '\n', 'isalnum')
        self.checkequal(True, '123abc456', 'isalnum')
        self.checkequal(True, 'a1b3c', 'isalnum')
        self.checkequal(False, 'aBc000 ', 'isalnum')
        self.checkequal(False, 'abc\n', 'isalnum')
        self.checkraises(TypeError, 'abc', 'isalnum', 42)

    def test_isascii(self):
        self.checkequal(True, '', 'isascii')
        self.checkequal(True, '\x00', 'isascii')
        self.checkequal(True, '\x7f', 'isascii')
        self.checkequal(True, '\x00\x7f', 'isascii')
        self.checkequal(False, '\x80', 'isascii')
        self.checkequal(False, '\xe9', 'isascii')
        # bytes.isascii() and bytearray.isascii() has optimization which
        # check 4 or 8 bytes at once.  So check some alignments.
        for p in range(8):
            self.checkequal(True, ' '*p + '\x7f', 'isascii')
            self.checkequal(False, ' '*p + '\x80', 'isascii')
            self.checkequal(True, ' '*p + '\x7f' + ' '*8, 'isascii')
            self.checkequal(False, ' '*p + '\x80' + ' '*8, 'isascii')

    def test_isdigit(self):
        self.checkequal(False, '', 'isdigit')
        self.checkequal(False, 'a', 'isdigit')
        self.checkequal(True, '0', 'isdigit')
        self.checkequal(True, '0123456789', 'isdigit')
        self.checkequal(False, '0123456789a', 'isdigit')

        self.checkraises(TypeError, 'abc', 'isdigit', 42)

    def test_title(self):
        self.checkequal(' Hello ', ' hello ', 'title')
        self.checkequal('Hello ', 'hello ', 'title')
        self.checkequal('Hello ', 'Hello ', 'title')
        self.checkequal('Format This As Title String', "fOrMaT thIs aS titLe String", 'title')
        self.checkequal('Format,This-As*Title;String', "fOrMaT,thIs-aS*titLe;String", 'title', )
        self.checkequal('Getint', "getInt", 'title')
        self.checkraises(TypeError, 'hello', 'title', 42)

    def test_splitlines(self):
        self.checkequal(['abc', 'def', '', 'ghi'], "abc\ndef\n\rghi", 'splitlines')
        self.checkequal(['abc', 'def', '', 'ghi'], "abc\ndef\n\r\nghi", 'splitlines')
        self.checkequal(['abc', 'def', 'ghi'], "abc\ndef\r\nghi", 'splitlines')
        self.checkequal(['abc', 'def', 'ghi'], "abc\ndef\r\nghi\n", 'splitlines')
        self.checkequal(['abc', 'def', 'ghi', ''], "abc\ndef\r\nghi\n\r", 'splitlines')
        self.checkequal(['', 'abc', 'def', 'ghi', ''], "\nabc\ndef\r\nghi\n\r", 'splitlines')
        self.checkequal(['', 'abc', 'def', 'ghi', ''],
                        "\nabc\ndef\r\nghi\n\r", 'splitlines', False)
        self.checkequal(['\n', 'abc\n', 'def\r\n', 'ghi\n', '\r'],
                        "\nabc\ndef\r\nghi\n\r", 'splitlines', True)
        self.checkequal(['', 'abc', 'def', 'ghi', ''], "\nabc\ndef\r\nghi\n\r",
                        'splitlines', keepends=False)
        self.checkequal(['\n', 'abc\n', 'def\r\n', 'ghi\n', '\r'],
                        "\nabc\ndef\r\nghi\n\r", 'splitlines', keepends=True)

        self.checkraises(TypeError, 'abc', 'splitlines', 42, 42)


class CommonTest(BaseTest):
    # This testcase contains tests that can be used in all
    # stringlike classes. Currently this is str and UserString.

    def test_hash(self):
        # SF bug 1054139:  += optimization was not invalidating cached hash value
        a = self.type2test('DNSSEC')
        b = self.type2test('')
        for c in a:
            b += c
            hash(b)
        self.assertEqual(hash(a), hash(b))

    def test_capitalize_nonascii(self):
        # check that titlecased chars are lowered correctly
        # \u1ffc is the titlecased char
        self.checkequal('\u1ffc\u1ff3\u1ff3\u1ff3',
                        '\u1ff3\u1ff3\u1ffc\u1ffc', 'capitalize')
        # check with cased non-letter chars
        self.checkequal('\u24c5\u24e8\u24e3\u24d7\u24de\u24dd',
                        '\u24c5\u24ce\u24c9\u24bd\u24c4\u24c3', 'capitalize')
        self.checkequal('\u24c5\u24e8\u24e3\u24d7\u24de\u24dd',
                        '\u24df\u24e8\u24e3\u24d7\u24de\u24dd', 'capitalize')
        self.checkequal('\u2160\u2171\u2172',
                        '\u2160\u2161\u2162', 'capitalize')
        self.checkequal('\u2160\u2171\u2172',
                        '\u2170\u2171\u2172', 'capitalize')
        # check with Ll chars with no upper - nothing changes here
        self.checkequal('\u019b\u1d00\u1d86\u0221\u1fb7',
                        '\u019b\u1d00\u1d86\u0221\u1fb7', 'capitalize')


class MixinStrUnicodeUserStringTest:
    # additional tests that only work for
    # stringlike objects, i.e. str, UserString

    def test_startswith(self):
        self.checkequal(True, 'hello', 'startswith', 'he')
        self.checkequal(True, 'hello', 'startswith', 'hello')
        self.checkequal(False, 'hello', 'startswith', 'hello world')
        self.checkequal(True, 'hello', 'startswith', '')
        self.checkequal(False, 'hello', 'startswith', 'ello')
        self.checkequal(True, 'hello', 'startswith', 'ello', 1)
        self.checkequal(True, 'hello', 'startswith', 'o', 4)
        self.checkequal(False, 'hello', 'startswith', 'o', 5)
        self.checkequal(True, 'hello', 'startswith', '', 5)
        self.checkequal(False, 'hello', 'startswith', 'lo', 6)
        self.checkequal(True, 'helloworld', 'startswith', 'lowo', 3)
        self.checkequal(True, 'helloworld', 'startswith', 'lowo', 3, 7)
        self.checkequal(False, 'helloworld', 'startswith', 'lowo', 3, 6)
        self.checkequal(True, '', 'startswith', '', 0, 1)
        self.checkequal(True, '', 'startswith', '', 0, 0)
        self.checkequal(False, '', 'startswith', '', 1, 0)

        # test negative indices
        self.checkequal(True, 'hello', 'startswith', 'he', 0, -1)
        self.checkequal(True, 'hello', 'startswith', 'he', -53, -1)
        self.checkequal(False, 'hello', 'startswith', 'hello', 0, -1)
        self.checkequal(False, 'hello', 'startswith', 'hello world', -1, -10)
        self.checkequal(False, 'hello', 'startswith', 'ello', -5)
        self.checkequal(True, 'hello', 'startswith', 'ello', -4)
        self.checkequal(False, 'hello', 'startswith', 'o', -2)
        self.checkequal(True, 'hello', 'startswith', 'o', -1)
        self.checkequal(True, 'hello', 'startswith', '', -3, -3)
        self.checkequal(False, 'hello', 'startswith', 'lo', -9)

        self.checkraises(TypeError, 'hello', 'startswith')
        self.checkraises(TypeError, 'hello', 'startswith', 42)

        # test tuple arguments
        self.checkequal(True, 'hello', 'startswith', ('he', 'ha'))
        self.checkequal(False, 'hello', 'startswith', ('lo', 'llo'))
        self.checkequal(True, 'hello', 'startswith', ('hellox', 'hello'))
        self.checkequal(False, 'hello', 'startswith', ())
        self.checkequal(True, 'helloworld', 'startswith', ('hellowo',
                                                           'rld', 'lowo'), 3)
        self.checkequal(False, 'helloworld', 'startswith', ('hellowo', 'ello',
                                                            'rld'), 3)
        self.checkequal(True, 'hello', 'startswith', ('lo', 'he'), 0, -1)
        self.checkequal(False, 'hello', 'startswith', ('he', 'hel'), 0, 1)
        self.checkequal(True, 'hello', 'startswith', ('he', 'hel'), 0, 2)

        self.checkraises(TypeError, 'hello', 'startswith', (42,))

    def test_endswith(self):
        self.checkequal(True, 'hello', 'endswith', 'lo')
        self.checkequal(False, 'hello', 'endswith', 'he')
        self.checkequal(True, 'hello', 'endswith', '')
        self.checkequal(False, 'hello', 'endswith', 'hello world')
        self.checkequal(False, 'helloworld', 'endswith', 'worl')
        self.checkequal(True, 'helloworld', 'endswith', 'worl', 3, 9)
        self.checkequal(True, 'helloworld', 'endswith', 'world', 3, 12)
        self.checkequal(True, 'helloworld', 'endswith', 'lowo', 1, 7)
        self.checkequal(True, 'helloworld', 'endswith', 'lowo', 2, 7)
        self.checkequal(True, 'helloworld', 'endswith', 'lowo', 3, 7)
        self.checkequal(False, 'helloworld', 'endswith', 'lowo', 4, 7)
        self.checkequal(False, 'helloworld', 'endswith', 'lowo', 3, 8)
        self.checkequal(False, 'ab', 'endswith', 'ab', 0, 1)
        self.checkequal(False, 'ab', 'endswith', 'ab', 0, 0)
        self.checkequal(True, '', 'endswith', '', 0, 1)
        self.checkequal(True, '', 'endswith', '', 0, 0)
        self.checkequal(False, '', 'endswith', '', 1, 0)

        # test negative indices
        self.checkequal(True, 'hello', 'endswith', 'lo', -2)
        self.checkequal(False, 'hello', 'endswith', 'he', -2)
        self.checkequal(True, 'hello', 'endswith', '', -3, -3)
        self.checkequal(False, 'hello', 'endswith', 'hello world', -10, -2)
        self.checkequal(False, 'helloworld', 'endswith', 'worl', -6)
        self.checkequal(True, 'helloworld', 'endswith', 'worl', -5, -1)
        self.checkequal(True, 'helloworld', 'endswith', 'worl', -5, 9)
        self.checkequal(True, 'helloworld', 'endswith', 'world', -7, 12)
        self.checkequal(True, 'helloworld', 'endswith', 'lowo', -99, -3)
        self.checkequal(True, 'helloworld', 'endswith', 'lowo', -8, -3)
        self.checkequal(True, 'helloworld', 'endswith', 'lowo', -7, -3)
        self.checkequal(False, 'helloworld', 'endswith', 'lowo', 3, -4)
        self.checkequal(False, 'helloworld', 'endswith', 'lowo', -8, -2)

        self.checkraises(TypeError, 'hello', 'endswith')
        self.checkraises(TypeError, 'hello', 'endswith', 42)

        # test tuple arguments
        self.checkequal(False, 'hello', 'endswith', ('he', 'ha'))
        self.checkequal(True, 'hello', 'endswith', ('lo', 'llo'))
        self.checkequal(True, 'hello', 'endswith', ('hellox', 'hello'))
        self.checkequal(False, 'hello', 'endswith', ())
        self.checkequal(True, 'helloworld', 'endswith', ('hellowo',
                                                           'rld', 'lowo'), 3)
        self.checkequal(False, 'helloworld', 'endswith', ('hellowo', 'ello',
                                                            'rld'), 3, -1)
        self.checkequal(True, 'hello', 'endswith', ('hell', 'ell'), 0, -1)
        self.checkequal(False, 'hello', 'endswith', ('he', 'hel'), 0, 1)
        self.checkequal(True, 'hello', 'endswith', ('he', 'hell'), 0, 4)

        self.checkraises(TypeError, 'hello', 'endswith', (42,))

    def test___contains__(self):
        self.checkequal(True, '', '__contains__', '')
        self.checkequal(True, 'abc', '__contains__', '')
        self.checkequal(False, 'abc', '__contains__', '\0')
        self.checkequal(True, '\0abc', '__contains__', '\0')
        self.checkequal(True, 'abc\0', '__contains__', '\0')
        self.checkequal(True, '\0abc', '__contains__', 'a')
        self.checkequal(True, 'asdf', '__contains__', 'asdf')
        self.checkequal(False, 'asd', '__contains__', 'asdf')
        self.checkequal(False, '', '__contains__', 'asdf')

    def test_subscript(self):
        self.checkequal('a', 'abc', '__getitem__', 0)
        self.checkequal('c', 'abc', '__getitem__', -1)
        self.checkequal('a', 'abc', '__getitem__', 0)
        self.checkequal('abc', 'abc', '__getitem__', slice(0, 3))
        self.checkequal('abc', 'abc', '__getitem__', slice(0, 1000))
        self.checkequal('a', 'abc', '__getitem__', slice(0, 1))
        self.checkequal('', 'abc', '__getitem__', slice(0, 0))

        self.checkraises(TypeError, 'abc', '__getitem__', 'def')

        for idx_type in ('def', object()):
            expected_msg = "string indices must be integers, not '{}'".format(type(idx_type).__name__)
            self.checkraises(TypeError, 'abc', '__getitem__', idx_type, expected_msg=expected_msg)

    def test_slice(self):
        self.checkequal('abc', 'abc', '__getitem__', slice(0, 1000))
        self.checkequal('abc', 'abc', '__getitem__', slice(0, 3))
        self.checkequal('ab', 'abc', '__getitem__', slice(0, 2))
        self.checkequal('bc', 'abc', '__getitem__', slice(1, 3))
        self.checkequal('b', 'abc', '__getitem__', slice(1, 2))
        self.checkequal('', 'abc', '__getitem__', slice(2, 2))
        self.checkequal('', 'abc', '__getitem__', slice(1000, 1000))
        self.checkequal('', 'abc', '__getitem__', slice(2000, 1000))
        self.checkequal('', 'abc', '__getitem__', slice(2, 1))

        self.checkraises(TypeError, 'abc', '__getitem__', 'def')

    def test_extended_getslice(self):
        # Test extended slicing by comparing with list slicing.
        s = string.ascii_letters + string.digits
        indices = (0, None, 1, 3, 41, sys.maxsize, -1, -2, -37)
        for start in indices:
            for stop in indices:
                # Skip step 0 (invalid)
                for step in indices[1:]:
                    L = list(s)[start:stop:step]
                    self.checkequal("".join(L), s, '__getitem__',
                                    slice(start, stop, step))

    def test_mul(self):
        self.checkequal('', 'abc', '__mul__', -1)
        self.checkequal('', 'abc', '__mul__', 0)
        self.checkequal('abc', 'abc', '__mul__', 1)
        self.checkequal('abcabcabc', 'abc', '__mul__', 3)
        self.checkraises(TypeError, 'abc', '__mul__')
        self.checkraises(TypeError, 'abc', '__mul__', '')
        # XXX: on a 64-bit system, this doesn't raise an overflow error,
        # but either raises a MemoryError, or succeeds (if you have 54TiB)
        #self.checkraises(OverflowError, 10000*'abc', '__mul__', 2000000000)

    def test_join(self):
        # join now works with any sequence type
        # moved here, because the argument order is
        # different in string.join
        self.checkequal('a b c d', ' ', 'join', ['a', 'b', 'c', 'd'])
        self.checkequal('abcd', '', 'join', ('a', 'b', 'c', 'd'))
        self.checkequal('bd', '', 'join', ('', 'b', '', 'd'))
        self.checkequal('ac', '', 'join', ('a', '', 'c', ''))
        self.checkequal('w x y z', ' ', 'join', Sequence())
        self.checkequal('abc', 'a', 'join', ('abc',))
        self.checkequal('z', 'a', 'join', UserList(['z']))
        self.checkequal('a.b.c', '.', 'join', ['a', 'b', 'c'])
        self.assertRaises(TypeError, '.'.join, ['a', 'b', 3])
        for i in [5, 25, 125]:
            self.checkequal(((('a' * i) + '-') * i)[:-1], '-', 'join',
                 ['a' * i] * i)
            self.checkequal(((('a' * i) + '-') * i)[:-1], '-', 'join',
                 ('a' * i,) * i)

        #self.checkequal(str(BadSeq1()), ' ', 'join', BadSeq1())
        self.checkequal('a b c', ' ', 'join', BadSeq2())

        self.checkraises(TypeError, ' ', 'join')
        self.checkraises(TypeError, ' ', 'join', None)
        self.checkraises(TypeError, ' ', 'join', 7)
        self.checkraises(TypeError, ' ', 'join', [1, 2, bytes()])
        try:
            def f():
                yield 4 + ""
            self.fixtype(' ').join(f())
        except TypeError as e:
            if '+' not in str(e):
                self.fail('join() ate exception message')
        else:
            self.fail('exception not raised')

    def test_formatting(self):
        self.checkequal('+hello+', '+%s+', '__mod__', 'hello')
        self.checkequal('+10+', '+%d+', '__mod__', 10)
        self.checkequal('a', "%c", '__mod__', "a")
        self.checkequal('a', "%c", '__mod__', "a")
        self.checkequal('"', "%c", '__mod__', 34)
        self.checkequal('$', "%c", '__mod__', 36)
        self.checkequal('10', "%d", '__mod__', 10)
        self.checkequal('\x7f', "%c", '__mod__', 0x7f)

        for ordinal in (-100, 0x200000):
            # unicode raises ValueError, str raises OverflowError
            self.checkraises((ValueError, OverflowError), '%c', '__mod__', ordinal)

        longvalue = sys.maxsize + 10
        slongvalue = str(longvalue)
        self.checkequal(' 42', '%3ld', '__mod__', 42)
        self.checkequal('42', '%d', '__mod__', 42.0)
        self.checkequal(slongvalue, '%d', '__mod__', longvalue)
        self.checkcall('%d', '__mod__', float(longvalue))
        self.checkequal('0042.00', '%07.2f', '__mod__', 42)
        self.checkequal('0042.00', '%07.2F', '__mod__', 42)

        self.checkraises(TypeError, 'abc', '__mod__')
        self.checkraises(TypeError, '%(foo)s', '__mod__', 42)
        self.checkraises(TypeError, '%s%s', '__mod__', (42,))
        self.checkraises(TypeError, '%c', '__mod__', (None,))
        self.checkraises(ValueError, '%(foo', '__mod__', {})
        self.checkraises(TypeError, '%(foo)s %(bar)s', '__mod__', ('foo', 42))
        self.checkraises(TypeError, '%d', '__mod__', "42") # not numeric
        self.checkraises(TypeError, '%d', '__mod__', (42+0j)) # no int conversion provided

        # argument names with properly nested brackets are supported
        self.checkequal('bar', '%((foo))s', '__mod__', {'(foo)': 'bar'})

        # 100 is a magic number in PyUnicode_Format, this forces a resize
        self.checkequal(103*'a'+'x', '%sx', '__mod__', 103*'a')

        self.checkraises(TypeError, '%*s', '__mod__', ('foo', 'bar'))
        self.checkraises(TypeError, '%10.*f', '__mod__', ('foo', 42.))
        self.checkraises(ValueError, '%10', '__mod__', (42,))

        # Outrageously large width or precision should raise ValueError.
        self.checkraises(ValueError, '%%%df' % (2**64), '__mod__', (3.2))
        self.checkraises(ValueError, '%%.%df' % (2**64), '__mod__', (3.2))
        self.checkraises(OverflowError, '%*s', '__mod__',
                         (sys.maxsize + 1, ''))
        self.checkraises(OverflowError, '%.*f', '__mod__',
                         (sys.maxsize + 1, 1. / 7))

        class X(object): pass
        self.checkraises(TypeError, 'abc', '__mod__', X())

    @support.cpython_only
    def test_formatting_c_limits(self):
        from _testcapi import PY_SSIZE_T_MAX, INT_MAX, UINT_MAX
        SIZE_MAX = (1 << (PY_SSIZE_T_MAX.bit_length() + 1)) - 1
        self.checkraises(OverflowError, '%*s', '__mod__',
                         (PY_SSIZE_T_MAX + 1, ''))
        self.checkraises(OverflowError, '%.*f', '__mod__',
                         (INT_MAX + 1, 1. / 7))
        # Issue 15989
        self.checkraises(OverflowError, '%*s', '__mod__',
                         (SIZE_MAX + 1, ''))
        self.checkraises(OverflowError, '%.*f', '__mod__',
                         (UINT_MAX + 1, 1. / 7))

    def test_floatformatting(self):
        # float formatting
        for prec in range(100):
            format = '%%.%if' % prec
            value = 0.01
            for x in range(60):
                value = value * 3.14159265359 / 3.0 * 10.0
                self.checkcall(format, "__mod__", value)

    def test_inplace_rewrites(self):
        # Check that strings don't copy and modify cached single-character strings
        self.checkequal('a', 'A', 'lower')
        self.checkequal(True, 'A', 'isupper')
        self.checkequal('A', 'a', 'upper')
        self.checkequal(True, 'a', 'islower')

        self.checkequal('a', 'A', 'replace', 'A', 'a')
        self.checkequal(True, 'A', 'isupper')

        self.checkequal('A', 'a', 'capitalize')
        self.checkequal(True, 'a', 'islower')

        self.checkequal('A', 'a', 'swapcase')
        self.checkequal(True, 'a', 'islower')

        self.checkequal('A', 'a', 'title')
        self.checkequal(True, 'a', 'islower')

    def test_partition(self):

        self.checkequal(('this is the par', 'ti', 'tion method'),
            'this is the partition method', 'partition', 'ti')

        # from raymond's original specification
        S = 'http://www.python.org'
        self.checkequal(('http', '://', 'www.python.org'), S, 'partition', '://')
        self.checkequal(('http://www.python.org', '', ''), S, 'partition', '?')
        self.checkequal(('', 'http://', 'www.python.org'), S, 'partition', 'http://')
        self.checkequal(('http://www.python.', 'org', ''), S, 'partition', 'org')

        self.checkraises(ValueError, S, 'partition', '')
        self.checkraises(TypeError, S, 'partition', None)

    def test_rpartition(self):

        self.checkequal(('this is the rparti', 'ti', 'on method'),
            'this is the rpartition method', 'rpartition', 'ti')

        # from raymond's original specification
        S = 'http://www.python.org'
        self.checkequal(('http', '://', 'www.python.org'), S, 'rpartition', '://')
        self.checkequal(('', '', 'http://www.python.org'), S, 'rpartition', '?')
        self.checkequal(('', 'http://', 'www.python.org'), S, 'rpartition', 'http://')
        self.checkequal(('http://www.python.', 'org', ''), S, 'rpartition', 'org')

        self.checkraises(ValueError, S, 'rpartition', '')
        self.checkraises(TypeError, S, 'rpartition', None)

    def test_none_arguments(self):
        # issue 11828
        s = 'hello'
        self.checkequal(2, s, 'find', 'l', None)
        self.checkequal(3, s, 'find', 'l', -2, None)
        self.checkequal(2, s, 'find', 'l', None, -2)
        self.checkequal(0, s, 'find', 'h', None, None)

        self.checkequal(3, s, 'rfind', 'l', None)
        self.checkequal(3, s, 'rfind', 'l', -2, None)
        self.checkequal(2, s, 'rfind', 'l', None, -2)
        self.checkequal(0, s, 'rfind', 'h', None, None)

        self.checkequal(2, s, 'index', 'l', None)
        self.checkequal(3, s, 'index', 'l', -2, None)
        self.checkequal(2, s, 'index', 'l', None, -2)
        self.checkequal(0, s, 'index', 'h', None, None)

        self.checkequal(3, s, 'rindex', 'l', None)
        self.checkequal(3, s, 'rindex', 'l', -2, None)
        self.checkequal(2, s, 'rindex', 'l', None, -2)
        self.checkequal(0, s, 'rindex', 'h', None, None)

        self.checkequal(2, s, 'count', 'l', None)
        self.checkequal(1, s, 'count', 'l', -2, None)
        self.checkequal(1, s, 'count', 'l', None, -2)
        self.checkequal(0, s, 'count', 'x', None, None)

        self.checkequal(True, s, 'endswith', 'o', None)
        self.checkequal(True, s, 'endswith', 'lo', -2, None)
        self.checkequal(True, s, 'endswith', 'l', None, -2)
        self.checkequal(False, s, 'endswith', 'x', None, None)

        self.checkequal(True, s, 'startswith', 'h', None)
        self.checkequal(True, s, 'startswith', 'l', -2, None)
        self.checkequal(True, s, 'startswith', 'h', None, -2)
        self.checkequal(False, s, 'startswith', 'x', None, None)

    def test_find_etc_raise_correct_error_messages(self):
        # issue 11828
        s = 'hello'
        x = 'x'
        self.assertRaisesRegex(TypeError, r'^find\(', s.find,
                                x, None, None, None)
        self.assertRaisesRegex(TypeError, r'^rfind\(', s.rfind,
                                x, None, None, None)
        self.assertRaisesRegex(TypeError, r'^index\(', s.index,
                                x, None, None, None)
        self.assertRaisesRegex(TypeError, r'^rindex\(', s.rindex,
                                x, None, None, None)
        self.assertRaisesRegex(TypeError, r'^count\(', s.count,
                                x, None, None, None)
        self.assertRaisesRegex(TypeError, r'^startswith\(', s.startswith,
                                x, None, None, None)
        self.assertRaisesRegex(TypeError, r'^endswith\(', s.endswith,
                                x, None, None, None)

        # issue #15534
        self.checkequal(10, "...\u043c......<", "find", "<")


class MixinStrUnicodeTest:
    # Additional tests that only work with str.

    def test_bug1001011(self):
        # Make sure join returns a NEW object for single item sequences
        # involving a subclass.
        # Make sure that it is of the appropriate type.
        # Check the optimisation still occurs for standard objects.
        t = self.type2test
        class subclass(t):
            pass
        s1 = subclass("abcd")
        s2 = t().join([s1])
        self.assertIsNot(s1, s2)
        self.assertIs(type(s2), t)

        s1 = t("abcd")
        s2 = t().join([s1])
        self.assertIs(s1, s2)