Lib/test/test_re.py

from test.support import verbose, run_unittest
import re
from re import Scanner
import sys, os, traceback
from weakref import proxy

# Misc tests from Tim Peters' re.doc

# WARNING: Don't change details in these tests if you don't know
# what you're doing. Some of these tests were carefuly modeled to
# cover most of the code.

import unittest

class ReTests(unittest.TestCase):

    def test_weakref(self):
        s = 'QabbbcR'
        x = re.compile('ab+c')
        y = proxy(x)
        self.assertEqual(x.findall('QabbbcR'), y.findall('QabbbcR'))

    def test_search_star_plus(self):
        self.assertEqual(re.search('x*', 'axx').span(0), (0, 0))
        self.assertEqual(re.search('x*', 'axx').span(), (0, 0))
        self.assertEqual(re.search('x+', 'axx').span(0), (1, 3))
        self.assertEqual(re.search('x+', 'axx').span(), (1, 3))
        self.assertEqual(re.search('x', 'aaa'), None)
        self.assertEqual(re.match('a*', 'xxx').span(0), (0, 0))
        self.assertEqual(re.match('a*', 'xxx').span(), (0, 0))
        self.assertEqual(re.match('x*', 'xxxa').span(0), (0, 3))
        self.assertEqual(re.match('x*', 'xxxa').span(), (0, 3))
        self.assertEqual(re.match('a+', 'xxx'), None)

    def bump_num(self, matchobj):
        int_value = int(matchobj.group(0))
        return str(int_value + 1)

    def test_basic_re_sub(self):
        self.assertEqual(re.sub("(?i)b+", "x", "bbbb BBBB"), 'x x')
        self.assertEqual(re.sub(r'\d+', self.bump_num, '08.2 -2 23x99y'),
                         '9.3 -3 24x100y')
        self.assertEqual(re.sub(r'\d+', self.bump_num, '08.2 -2 23x99y', 3),
                         '9.3 -3 23x99y')

        self.assertEqual(re.sub('.', lambda m: r"\n", 'x'), '\\n')
        self.assertEqual(re.sub('.', r"\n", 'x'), '\n')

        s = r"\1\1"
        self.assertEqual(re.sub('(.)', s, 'x'), 'xx')
        self.assertEqual(re.sub('(.)', re.escape(s), 'x'), s)
        self.assertEqual(re.sub('(.)', lambda m: s, 'x'), s)

        self.assertEqual(re.sub('(?P<a>x)', '\g<a>\g<a>', 'xx'), 'xxxx')
        self.assertEqual(re.sub('(?P<a>x)', '\g<a>\g<1>', 'xx'), 'xxxx')
        self.assertEqual(re.sub('(?P<unk>x)', '\g<unk>\g<unk>', 'xx'), 'xxxx')
        self.assertEqual(re.sub('(?P<unk>x)', '\g<1>\g<1>', 'xx'), 'xxxx')

        self.assertEqual(re.sub('a',r'\t\n\v\r\f\a\b\B\Z\a\A\w\W\s\S\d\D','a'),
                         '\t\n\v\r\f\a\b\\B\\Z\a\\A\\w\\W\\s\\S\\d\\D')
        self.assertEqual(re.sub('a', '\t\n\v\r\f\a', 'a'), '\t\n\v\r\f\a')
        self.assertEqual(re.sub('a', '\t\n\v\r\f\a', 'a'),
                         (chr(9)+chr(10)+chr(11)+chr(13)+chr(12)+chr(7)))

        self.assertEqual(re.sub('^\s*', 'X', 'test'), 'Xtest')

    def test_bug_449964(self):
        # fails for group followed by other escape
        self.assertEqual(re.sub(r'(?P<unk>x)', '\g<1>\g<1>\\b', 'xx'),
                         'xx\bxx\b')

    def test_bug_449000(self):
        # Test for sub() on escaped characters
        self.assertEqual(re.sub(r'\r\n', r'\n', 'abc\r\ndef\r\n'),
                         'abc\ndef\n')
        self.assertEqual(re.sub('\r\n', r'\n', 'abc\r\ndef\r\n'),
                         'abc\ndef\n')
        self.assertEqual(re.sub(r'\r\n', '\n', 'abc\r\ndef\r\n'),
                         'abc\ndef\n')
        self.assertEqual(re.sub('\r\n', '\n', 'abc\r\ndef\r\n'),
                         'abc\ndef\n')

    def test_bug_1661(self):
        # Verify that flags do not get silently ignored with compiled patterns
        pattern = re.compile('.')
        self.assertRaises(ValueError, re.match, pattern, 'A', re.I)
        self.assertRaises(ValueError, re.search, pattern, 'A', re.I)
        self.assertRaises(ValueError, re.findall, pattern, 'A', re.I)
        self.assertRaises(ValueError, re.compile, pattern, re.I)

    def test_bug_3629(self):
        # A regex that triggered a bug in the sre-code validator
        re.compile("(?P<quote>)(?(quote))")

    def test_sub_template_numeric_escape(self):
        # bug 776311 and friends
        self.assertEqual(re.sub('x', r'\0', 'x'), '\0')
        self.assertEqual(re.sub('x', r'\000', 'x'), '\000')
        self.assertEqual(re.sub('x', r'\001', 'x'), '\001')
        self.assertEqual(re.sub('x', r'\008', 'x'), '\0' + '8')
        self.assertEqual(re.sub('x', r'\009', 'x'), '\0' + '9')
        self.assertEqual(re.sub('x', r'\111', 'x'), '\111')
        self.assertEqual(re.sub('x', r'\117', 'x'), '\117')

        self.assertEqual(re.sub('x', r'\1111', 'x'), '\1111')
        self.assertEqual(re.sub('x', r'\1111', 'x'), '\111' + '1')

        self.assertEqual(re.sub('x', r'\00', 'x'), '\x00')
        self.assertEqual(re.sub('x', r'\07', 'x'), '\x07')
        self.assertEqual(re.sub('x', r'\08', 'x'), '\0' + '8')
        self.assertEqual(re.sub('x', r'\09', 'x'), '\0' + '9')
        self.assertEqual(re.sub('x', r'\0a', 'x'), '\0' + 'a')

        self.assertEqual(re.sub('x', r'\400', 'x'), '\0')
        self.assertEqual(re.sub('x', r'\777', 'x'), '\377')

        self.assertRaises(re.error, re.sub, 'x', r'\1', 'x')
        self.assertRaises(re.error, re.sub, 'x', r'\8', 'x')
        self.assertRaises(re.error, re.sub, 'x', r'\9', 'x')
        self.assertRaises(re.error, re.sub, 'x', r'\11', 'x')
        self.assertRaises(re.error, re.sub, 'x', r'\18', 'x')
        self.assertRaises(re.error, re.sub, 'x', r'\1a', 'x')
        self.assertRaises(re.error, re.sub, 'x', r'\90', 'x')
        self.assertRaises(re.error, re.sub, 'x', r'\99', 'x')
        self.assertRaises(re.error, re.sub, 'x', r'\118', 'x') # r'\11' + '8'
        self.assertRaises(re.error, re.sub, 'x', r'\11a', 'x')
        self.assertRaises(re.error, re.sub, 'x', r'\181', 'x') # r'\18' + '1'
        self.assertRaises(re.error, re.sub, 'x', r'\800', 'x') # r'\80' + '0'

        # in python2.3 (etc), these loop endlessly in sre_parser.py
        self.assertEqual(re.sub('(((((((((((x)))))))))))', r'\11', 'x'), 'x')
        self.assertEqual(re.sub('((((((((((y))))))))))(.)', r'\118', 'xyz'),
                         'xz8')
        self.assertEqual(re.sub('((((((((((y))))))))))(.)', r'\11a', 'xyz'),
                         'xza')

    def test_qualified_re_sub(self):
        self.assertEqual(re.sub('a', 'b', 'aaaaa'), 'bbbbb')
        self.assertEqual(re.sub('a', 'b', 'aaaaa', 1), 'baaaa')

    def test_bug_114660(self):
        self.assertEqual(re.sub(r'(\S)\s+(\S)', r'\1 \2', 'hello  there'),
                         'hello there')

    def test_bug_462270(self):
        # Test for empty sub() behaviour, see SF bug #462270
        self.assertEqual(re.sub('x*', '-', 'abxd'), '-a-b-d-')
        self.assertEqual(re.sub('x+', '-', 'abxd'), 'ab-d')

    def test_symbolic_refs(self):
        self.assertRaises(re.error, re.sub, '(?P<a>x)', '\g<a', 'xx')
        self.assertRaises(re.error, re.sub, '(?P<a>x)', '\g<', 'xx')
        self.assertRaises(re.error, re.sub, '(?P<a>x)', '\g', 'xx')
        self.assertRaises(re.error, re.sub, '(?P<a>x)', '\g<a a>', 'xx')
        self.assertRaises(re.error, re.sub, '(?P<a>x)', '\g<1a1>', 'xx')
        self.assertRaises(IndexError, re.sub, '(?P<a>x)', '\g<ab>', 'xx')
        self.assertRaises(re.error, re.sub, '(?P<a>x)|(?P<b>y)', '\g<b>', 'xx')
        self.assertRaises(re.error, re.sub, '(?P<a>x)|(?P<b>y)', '\\2', 'xx')
        self.assertRaises(re.error, re.sub, '(?P<a>x)', '\g<-1>', 'xx')

    def test_re_subn(self):
        self.assertEqual(re.subn("(?i)b+", "x", "bbbb BBBB"), ('x x', 2))
        self.assertEqual(re.subn("b+", "x", "bbbb BBBB"), ('x BBBB', 1))
        self.assertEqual(re.subn("b+", "x", "xyz"), ('xyz', 0))
        self.assertEqual(re.subn("b*", "x", "xyz"), ('xxxyxzx', 4))
        self.assertEqual(re.subn("b*", "x", "xyz", 2), ('xxxyz', 2))

    def test_re_split(self):
        self.assertEqual(re.split(":", ":a:b::c"), ['', 'a', 'b', '', 'c'])
        self.assertEqual(re.split(":*", ":a:b::c"), ['', 'a', 'b', 'c'])
        self.assertEqual(re.split("(:*)", ":a:b::c"),
                         ['', ':', 'a', ':', 'b', '::', 'c'])
        self.assertEqual(re.split("(?::*)", ":a:b::c"), ['', 'a', 'b', 'c'])
        self.assertEqual(re.split("(:)*", ":a:b::c"),
                         ['', ':', 'a', ':', 'b', ':', 'c'])
        self.assertEqual(re.split("([b:]+)", ":a:b::c"),
                         ['', ':', 'a', ':b::', 'c'])
        self.assertEqual(re.split("(b)|(:+)", ":a:b::c"),
                         ['', None, ':', 'a', None, ':', '', 'b', None, '',
                          None, '::', 'c'])
        self.assertEqual(re.split("(?:b)|(?::+)", ":a:b::c"),
                         ['', 'a', '', '', 'c'])

    def test_qualified_re_split(self):
        self.assertEqual(re.split(":", ":a:b::c", 2), ['', 'a', 'b::c'])
        self.assertEqual(re.split(':', 'a:b:c:d', 2), ['a', 'b', 'c:d'])
        self.assertEqual(re.split("(:)", ":a:b::c", 2),
                         ['', ':', 'a', ':', 'b::c'])
        self.assertEqual(re.split("(:*)", ":a:b::c", 2),
                         ['', ':', 'a', ':', 'b::c'])

    def test_re_findall(self):
        self.assertEqual(re.findall(":+", "abc"), [])
        self.assertEqual(re.findall(":+", "a:b::c:::d"), [":", "::", ":::"])
        self.assertEqual(re.findall("(:+)", "a:b::c:::d"), [":", "::", ":::"])
        self.assertEqual(re.findall("(:)(:*)", "a:b::c:::d"), [(":", ""),
                                                               (":", ":"),
                                                               (":", "::")])

    def test_bug_117612(self):
        self.assertEqual(re.findall(r"(a|(b))", "aba"),
                         [("a", ""),("b", "b"),("a", "")])

    def test_re_match(self):
        self.assertEqual(re.match('a', 'a').groups(), ())
        self.assertEqual(re.match('(a)', 'a').groups(), ('a',))
        self.assertEqual(re.match(r'(a)', 'a').group(0), 'a')
        self.assertEqual(re.match(r'(a)', 'a').group(1), 'a')
        self.assertEqual(re.match(r'(a)', 'a').group(1, 1), ('a', 'a'))

        pat = re.compile('((a)|(b))(c)?')
        self.assertEqual(pat.match('a').groups(), ('a', 'a', None, None))
        self.assertEqual(pat.match('b').groups(), ('b', None, 'b', None))
        self.assertEqual(pat.match('ac').groups(), ('a', 'a', None, 'c'))
        self.assertEqual(pat.match('bc').groups(), ('b', None, 'b', 'c'))
        self.assertEqual(pat.match('bc').groups(""), ('b', "", 'b', 'c'))

        # A single group
        m = re.match('(a)', 'a')
        self.assertEqual(m.group(0), 'a')
        self.assertEqual(m.group(0), 'a')
        self.assertEqual(m.group(1), 'a')
        self.assertEqual(m.group(1, 1), ('a', 'a'))

        pat = re.compile('(?:(?P<a1>a)|(?P<b2>b))(?P<c3>c)?')
        self.assertEqual(pat.match('a').group(1, 2, 3), ('a', None, None))
        self.assertEqual(pat.match('b').group('a1', 'b2', 'c3'),
                         (None, 'b', None))
        self.assertEqual(pat.match('ac').group(1, 'b2', 3), ('a', None, 'c'))

    def test_re_groupref_exists(self):
        self.assertEqual(re.match('^(\()?([^()]+)(?(1)\))$', '(a)').groups(),
                         ('(', 'a'))
        self.assertEqual(re.match('^(\()?([^()]+)(?(1)\))$', 'a').groups(),
                         (None, 'a'))
        self.assertEqual(re.match('^(\()?([^()]+)(?(1)\))$', 'a)'), None)
        self.assertEqual(re.match('^(\()?([^()]+)(?(1)\))$', '(a'), None)
        self.assertEqual(re.match('^(?:(a)|c)((?(1)b|d))$', 'ab').groups(),
                         ('a', 'b'))
        self.assertEqual(re.match('^(?:(a)|c)((?(1)b|d))$', 'cd').groups(),
                         (None, 'd'))
        self.assertEqual(re.match('^(?:(a)|c)((?(1)|d))$', 'cd').groups(),
                         (None, 'd'))
        self.assertEqual(re.match('^(?:(a)|c)((?(1)|d))$', 'a').groups(),
                         ('a', ''))

        # Tests for bug #1177831: exercise groups other than the first group
        p = re.compile('(?P<g1>a)(?P<g2>b)?((?(g2)c|d))')
        self.assertEqual(p.match('abc').groups(),
                         ('a', 'b', 'c'))
        self.assertEqual(p.match('ad').groups(),
                         ('a', None, 'd'))
        self.assertEqual(p.match('abd'), None)
        self.assertEqual(p.match('ac'), None)


    def test_re_groupref(self):
        self.assertEqual(re.match(r'^(\|)?([^()]+)\1$', '|a|').groups(),
                         ('|', 'a'))
        self.assertEqual(re.match(r'^(\|)?([^()]+)\1?$', 'a').groups(),
                         (None, 'a'))
        self.assertEqual(re.match(r'^(\|)?([^()]+)\1$', 'a|'), None)
        self.assertEqual(re.match(r'^(\|)?([^()]+)\1$', '|a'), None)
        self.assertEqual(re.match(r'^(?:(a)|c)(\1)$', 'aa').groups(),
                         ('a', 'a'))
        self.assertEqual(re.match(r'^(?:(a)|c)(\1)?$', 'c').groups(),
                         (None, None))

    def test_groupdict(self):
        self.assertEqual(re.match('(?P<first>first) (?P<second>second)',
                                  'first second').groupdict(),
                         {'first':'first', 'second':'second'})

    def test_expand(self):
        self.assertEqual(re.match("(?P<first>first) (?P<second>second)",
                                  "first second")
                                  .expand(r"\2 \1 \g<second> \g<first>"),
                         "second first second first")

    def test_repeat_minmax(self):
        self.assertEqual(re.match("^(\w){1}$", "abc"), None)
        self.assertEqual(re.match("^(\w){1}?$", "abc"), None)
        self.assertEqual(re.match("^(\w){1,2}$", "abc"), None)
        self.assertEqual(re.match("^(\w){1,2}?$", "abc"), None)

        self.assertEqual(re.match("^(\w){3}$", "abc").group(1), "c")
        self.assertEqual(re.match("^(\w){1,3}$", "abc").group(1), "c")
        self.assertEqual(re.match("^(\w){1,4}$", "abc").group(1), "c")
        self.assertEqual(re.match("^(\w){3,4}?$", "abc").group(1), "c")
        self.assertEqual(re.match("^(\w){3}?$", "abc").group(1), "c")
        self.assertEqual(re.match("^(\w){1,3}?$", "abc").group(1), "c")
        self.assertEqual(re.match("^(\w){1,4}?$", "abc").group(1), "c")
        self.assertEqual(re.match("^(\w){3,4}?$", "abc").group(1), "c")

        self.assertEqual(re.match("^x{1}$", "xxx"), None)
        self.assertEqual(re.match("^x{1}?$", "xxx"), None)
        self.assertEqual(re.match("^x{1,2}$", "xxx"), None)
        self.assertEqual(re.match("^x{1,2}?$", "xxx"), None)

        self.assertNotEqual(re.match("^x{3}$", "xxx"), None)
        self.assertNotEqual(re.match("^x{1,3}$", "xxx"), None)
        self.assertNotEqual(re.match("^x{1,4}$", "xxx"), None)
        self.assertNotEqual(re.match("^x{3,4}?$", "xxx"), None)
        self.assertNotEqual(re.match("^x{3}?$", "xxx"), None)
        self.assertNotEqual(re.match("^x{1,3}?$", "xxx"), None)
        self.assertNotEqual(re.match("^x{1,4}?$", "xxx"), None)
        self.assertNotEqual(re.match("^x{3,4}?$", "xxx"), None)

        self.assertEqual(re.match("^x{}$", "xxx"), None)
        self.assertNotEqual(re.match("^x{}$", "x{}"), None)

    def test_getattr(self):
        self.assertEqual(re.compile("(?i)(a)(b)").pattern, "(?i)(a)(b)")
        self.assertEqual(re.compile("(?i)(a)(b)").flags, re.I | re.U)
        self.assertEqual(re.compile("(?i)(a)(b)").groups, 2)
        self.assertEqual(re.compile("(?i)(a)(b)").groupindex, {})
        self.assertEqual(re.compile("(?i)(?P<first>a)(?P<other>b)").groupindex,
                         {'first': 1, 'other': 2})

        self.assertEqual(re.match("(a)", "a").pos, 0)
        self.assertEqual(re.match("(a)", "a").endpos, 1)
        self.assertEqual(re.match("(a)", "a").string, "a")
        self.assertEqual(re.match("(a)", "a").regs, ((0, 1), (0, 1)))
        self.assertNotEqual(re.match("(a)", "a").re, None)

    def test_special_escapes(self):
        self.assertEqual(re.search(r"\b(b.)\b",
                                   "abcd abc bcd bx").group(1), "bx")
        self.assertEqual(re.search(r"\B(b.)\B",
                                   "abc bcd bc abxd").group(1), "bx")
        self.assertEqual(re.search(r"\b(b.)\b",
                                   "abcd abc bcd bx", re.LOCALE).group(1), "bx")
        self.assertEqual(re.search(r"\B(b.)\B",
                                   "abc bcd bc abxd", re.LOCALE).group(1), "bx")
        self.assertEqual(re.search(r"\b(b.)\b",
                                   "abcd abc bcd bx", re.UNICODE).group(1), "bx")
        self.assertEqual(re.search(r"\B(b.)\B",
                                   "abc bcd bc abxd", re.UNICODE).group(1), "bx")
        self.assertEqual(re.search(r"^abc$", "\nabc\n", re.M).group(0), "abc")
        self.assertEqual(re.search(r"^\Aabc\Z$", "abc", re.M).group(0), "abc")
        self.assertEqual(re.search(r"^\Aabc\Z$", "\nabc\n", re.M), None)
        self.assertEqual(re.search(r"\b(b.)\b",
                                   "abcd abc bcd bx").group(1), "bx")
        self.assertEqual(re.search(r"\B(b.)\B",
                                   "abc bcd bc abxd").group(1), "bx")
        self.assertEqual(re.search(r"^abc$", "\nabc\n", re.M).group(0), "abc")
        self.assertEqual(re.search(r"^\Aabc\Z$", "abc", re.M).group(0), "abc")
        self.assertEqual(re.search(r"^\Aabc\Z$", "\nabc\n", re.M), None)
        self.assertEqual(re.search(r"\d\D\w\W\s\S",
                                   "1aa! a").group(0), "1aa! a")
        self.assertEqual(re.search(r"\d\D\w\W\s\S",
                                   "1aa! a", re.LOCALE).group(0), "1aa! a")
        self.assertEqual(re.search(r"\d\D\w\W\s\S",
                                   "1aa! a", re.UNICODE).group(0), "1aa! a")

    def test_bigcharset(self):
        self.assertEqual(re.match("([\u2222\u2223])",
                                  "\u2222").group(1), "\u2222")
        self.assertEqual(re.match("([\u2222\u2223])",
                                  "\u2222", re.UNICODE).group(1), "\u2222")

    def test_anyall(self):
        self.assertEqual(re.match("a.b", "a\nb", re.DOTALL).group(0),
                         "a\nb")
        self.assertEqual(re.match("a.*b", "a\n\nb", re.DOTALL).group(0),
                         "a\n\nb")

    def test_non_consuming(self):
        self.assertEqual(re.match("(a(?=\s[^a]))", "a b").group(1), "a")
        self.assertEqual(re.match("(a(?=\s[^a]*))", "a b").group(1), "a")
        self.assertEqual(re.match("(a(?=\s[abc]))", "a b").group(1), "a")
        self.assertEqual(re.match("(a(?=\s[abc]*))", "a bc").group(1), "a")
        self.assertEqual(re.match(r"(a)(?=\s\1)", "a a").group(1), "a")
        self.assertEqual(re.match(r"(a)(?=\s\1*)", "a aa").group(1), "a")
        self.assertEqual(re.match(r"(a)(?=\s(abc|a))", "a a").group(1), "a")

        self.assertEqual(re.match(r"(a(?!\s[^a]))", "a a").group(1), "a")
        self.assertEqual(re.match(r"(a(?!\s[abc]))", "a d").group(1), "a")
        self.assertEqual(re.match(r"(a)(?!\s\1)", "a b").group(1), "a")
        self.assertEqual(re.match(r"(a)(?!\s(abc|a))", "a b").group(1), "a")

    def test_ignore_case(self):
        self.assertEqual(re.match("abc", "ABC", re.I).group(0), "ABC")
        self.assertEqual(re.match("abc", "ABC", re.I).group(0), "ABC")
        self.assertEqual(re.match(r"(a\s[^a])", "a b", re.I).group(1), "a b")
        self.assertEqual(re.match(r"(a\s[^a]*)", "a bb", re.I).group(1), "a bb")
        self.assertEqual(re.match(r"(a\s[abc])", "a b", re.I).group(1), "a b")
        self.assertEqual(re.match(r"(a\s[abc]*)", "a bb", re.I).group(1), "a bb")
        self.assertEqual(re.match(r"((a)\s\2)", "a a", re.I).group(1), "a a")
        self.assertEqual(re.match(r"((a)\s\2*)", "a aa", re.I).group(1), "a aa")
        self.assertEqual(re.match(r"((a)\s(abc|a))", "a a", re.I).group(1), "a a")
        self.assertEqual(re.match(r"((a)\s(abc|a)*)", "a aa", re.I).group(1), "a aa")

    def test_category(self):
        self.assertEqual(re.match(r"(\s)", " ").group(1), " ")

    def test_getlower(self):
        import _sre
        self.assertEqual(_sre.getlower(ord('A'), 0), ord('a'))
        self.assertEqual(_sre.getlower(ord('A'), re.LOCALE), ord('a'))
        self.assertEqual(_sre.getlower(ord('A'), re.UNICODE), ord('a'))

        self.assertEqual(re.match("abc", "ABC", re.I).group(0), "ABC")
        self.assertEqual(re.match("abc", "ABC", re.I).group(0), "ABC")

    def test_not_literal(self):
        self.assertEqual(re.search("\s([^a])", " b").group(1), "b")
        self.assertEqual(re.search("\s([^a]*)", " bb").group(1), "bb")

    def test_search_coverage(self):
        self.assertEqual(re.search("\s(b)", " b").group(1), "b")
        self.assertEqual(re.search("a\s", "a ").group(0), "a ")

    def test_re_escape(self):
        p=""
        self.assertEqual(re.escape(p), p)
        for i in range(0, 256):
            p = p + chr(i)
            self.assertEqual(re.match(re.escape(chr(i)), chr(i)) is not None,
                             True)
            self.assertEqual(re.match(re.escape(chr(i)), chr(i)).span(), (0,1))

        pat=re.compile(re.escape(p))
        self.assertEqual(pat.match(p) is not None, True)
        self.assertEqual(pat.match(p).span(), (0,256))

    def test_re_escape_byte(self):
        p=b""
        self.assertEqual(re.escape(p), p)
        for i in range(0, 256):
            b = bytes([i])
            p += b
            self.assertEqual(re.match(re.escape(b), b) is not None, True)
            self.assertEqual(re.match(re.escape(b), b).span(), (0,1))

        pat=re.compile(re.escape(p))
        self.assertEqual(pat.match(p) is not None, True)
        self.assertEqual(pat.match(p).span(), (0,256))

    def pickle_test(self, pickle):
        oldpat = re.compile('a(?:b|(c|e){1,2}?|d)+?(.)')
        s = pickle.dumps(oldpat)
        newpat = pickle.loads(s)
        self.assertEqual(oldpat, newpat)

    def test_constants(self):
        self.assertEqual(re.I, re.IGNORECASE)
        self.assertEqual(re.L, re.LOCALE)
        self.assertEqual(re.M, re.MULTILINE)
        self.assertEqual(re.S, re.DOTALL)
        self.assertEqual(re.X, re.VERBOSE)

    def test_flags(self):
        for flag in [re.I, re.M, re.X, re.S, re.L]:
            self.assertNotEqual(re.compile('^pattern$', flag), None)

    def test_sre_character_literals(self):
        for i in [0, 8, 16, 32, 64, 127, 128, 255]:
            self.assertNotEqual(re.match(r"\%03o" % i, chr(i)), None)
            self.assertNotEqual(re.match(r"\%03o0" % i, chr(i)+"0"), None)
            self.assertNotEqual(re.match(r"\%03o8" % i, chr(i)+"8"), None)
            self.assertNotEqual(re.match(r"\x%02x" % i, chr(i)), None)
            self.assertNotEqual(re.match(r"\x%02x0" % i, chr(i)+"0"), None)
            self.assertNotEqual(re.match(r"\x%02xz" % i, chr(i)+"z"), None)
        self.assertRaises(re.error, re.match, "\911", "")

    def test_sre_character_class_literals(self):
        for i in [0, 8, 16, 32, 64, 127, 128, 255]:
            self.assertNotEqual(re.match(r"[\%03o]" % i, chr(i)), None)
            self.assertNotEqual(re.match(r"[\%03o0]" % i, chr(i)), None)
            self.assertNotEqual(re.match(r"[\%03o8]" % i, chr(i)), None)
            self.assertNotEqual(re.match(r"[\x%02x]" % i, chr(i)), None)
            self.assertNotEqual(re.match(r"[\x%02x0]" % i, chr(i)), None)
            self.assertNotEqual(re.match(r"[\x%02xz]" % i, chr(i)), None)
        self.assertRaises(re.error, re.match, "[\911]", "")

    def test_bug_113254(self):
        self.assertEqual(re.match(r'(a)|(b)', 'b').start(1), -1)
        self.assertEqual(re.match(r'(a)|(b)', 'b').end(1), -1)
        self.assertEqual(re.match(r'(a)|(b)', 'b').span(1), (-1, -1))

    def test_bug_527371(self):
        # bug described in patches 527371/672491
        self.assertEqual(re.match(r'(a)?a','a').lastindex, None)
        self.assertEqual(re.match(r'(a)(b)?b','ab').lastindex, 1)
        self.assertEqual(re.match(r'(?P<a>a)(?P<b>b)?b','ab').lastgroup, 'a')
        self.assertEqual(re.match("(?P<a>a(b))", "ab").lastgroup, 'a')
        self.assertEqual(re.match("((a))", "a").lastindex, 1)

    def test_bug_545855(self):
        # bug 545855 -- This pattern failed to cause a compile error as it
        # should, instead provoking a TypeError.
        self.assertRaises(re.error, re.compile, 'foo[a-')

    def test_bug_418626(self):
        # bugs 418626 at al. -- Testing Greg Chapman's addition of op code
        # SRE_OP_MIN_REPEAT_ONE for eliminating recursion on simple uses of
        # pattern '*?' on a long string.
        self.assertEqual(re.match('.*?c', 10000*'ab'+'cd').end(0), 20001)
        self.assertEqual(re.match('.*?cd', 5000*'ab'+'c'+5000*'ab'+'cde').end(0),
                         20003)
        self.assertEqual(re.match('.*?cd', 20000*'abc'+'de').end(0), 60001)
        # non-simple '*?' still used to hit the recursion limit, before the
        # non-recursive scheme was implemented.
        self.assertEqual(re.search('(a|b)*?c', 10000*'ab'+'cd').end(0), 20001)

    def test_bug_612074(self):
        pat="["+re.escape("\u2039")+"]"
        self.assertEqual(re.compile(pat) and 1, 1)

    def test_stack_overflow(self):
        # nasty cases that used to overflow the straightforward recursive
        # implementation of repeated groups.
        self.assertEqual(re.match('(x)*', 50000*'x').group(1), 'x')
        self.assertEqual(re.match('(x)*y', 50000*'x'+'y').group(1), 'x')
        self.assertEqual(re.match('(x)*?y', 50000*'x'+'y').group(1), 'x')

    def test_scanner(self):
        def s_ident(scanner, token): return token
        def s_operator(scanner, token): return "op%s" % token
        def s_float(scanner, token): return float(token)
        def s_int(scanner, token): return int(token)

        scanner = Scanner([
            (r"[a-zA-Z_]\w*", s_ident),
            (r"\d+\.\d*", s_float),
            (r"\d+", s_int),
            (r"=|\+|-|\*|/", s_operator),
            (r"\s+", None),
            ])

        self.assertNotEqual(scanner.scanner.scanner("").pattern, None)

        self.assertEqual(scanner.scan("sum = 3*foo + 312.50 + bar"),
                         (['sum', 'op=', 3, 'op*', 'foo', 'op+', 312.5,
                           'op+', 'bar'], ''))

    def test_bug_448951(self):
        # bug 448951 (similar to 429357, but with single char match)
        # (Also test greedy matches.)
        for op in '','?','*':
            self.assertEqual(re.match(r'((.%s):)?z'%op, 'z').groups(),
                             (None, None))
            self.assertEqual(re.match(r'((.%s):)?z'%op, 'a:z').groups(),
                             ('a:', 'a'))

    def test_bug_725106(self):
        # capturing groups in alternatives in repeats
        self.assertEqual(re.match('^((a)|b)*', 'abc').groups(),
                         ('b', 'a'))
        self.assertEqual(re.match('^(([ab])|c)*', 'abc').groups(),
                         ('c', 'b'))
        self.assertEqual(re.match('^((d)|[ab])*', 'abc').groups(),
                         ('b', None))
        self.assertEqual(re.match('^((a)c|[ab])*', 'abc').groups(),
                         ('b', None))
        self.assertEqual(re.match('^((a)|b)*?c', 'abc').groups(),
                         ('b', 'a'))
        self.assertEqual(re.match('^(([ab])|c)*?d', 'abcd').groups(),
                         ('c', 'b'))
        self.assertEqual(re.match('^((d)|[ab])*?c', 'abc').groups(),
                         ('b', None))
        self.assertEqual(re.match('^((a)c|[ab])*?c', 'abc').groups(),
                         ('b', None))

    def test_bug_725149(self):
        # mark_stack_base restoring before restoring marks
        self.assertEqual(re.match('(a)(?:(?=(b)*)c)*', 'abb').groups(),
                         ('a', None))
        self.assertEqual(re.match('(a)((?!(b)*))*', 'abb').groups(),
                         ('a', None, None))

    def test_bug_764548(self):
        # bug 764548, re.compile() barfs on str/unicode subclasses
        class my_unicode(str): pass
        pat = re.compile(my_unicode("abc"))
        self.assertEqual(pat.match("xyz"), None)

    def test_finditer(self):
        iter = re.finditer(r":+", "a:b::c:::d")
        self.assertEqual([item.group(0) for item in iter],
                         [":", "::", ":::"])

    def test_bug_926075(self):
        self.assertTrue(re.compile('bug_926075') is not
                     re.compile(b'bug_926075'))

    def test_bug_931848(self):
        pattern = eval('"[\u002E\u3002\uFF0E\uFF61]"')
        self.assertEqual(re.compile(pattern).split("a.b.c"),
                         ['a','b','c'])

    def test_bug_581080(self):
        iter = re.finditer(r"\s", "a b")
        self.assertEqual(next(iter).span(), (1,2))
        self.assertRaises(StopIteration, next, iter)

        scanner = re.compile(r"\s").scanner("a b")
        self.assertEqual(scanner.search().span(), (1, 2))
        self.assertEqual(scanner.search(), None)

    def test_bug_817234(self):
        iter = re.finditer(r".*", "asdf")
        self.assertEqual(next(iter).span(), (0, 4))
        self.assertEqual(next(iter).span(), (4, 4))
        self.assertRaises(StopIteration, next, iter)

    def test_bug_6561(self):
        # '\d' should match characters in Unicode category 'Nd'
        # (Number, Decimal Digit), but not those in 'Nl' (Number,
        # Letter) or 'No' (Number, Other).
        decimal_digits = [
            '\u0037', # '\N{DIGIT SEVEN}', category 'Nd'
            '\u0e58', # '\N{THAI DIGIT SIX}', category 'Nd'
            '\uff10', # '\N{FULLWIDTH DIGIT ZERO}', category 'Nd'
            ]
        for x in decimal_digits:
            self.assertEqual(re.match('^\d$', x).group(0), x)

        not_decimal_digits = [
            '\u2165', # '\N{ROMAN NUMERAL SIX}', category 'Nl'
            '\u3039', # '\N{HANGZHOU NUMERAL TWENTY}', category 'Nl'
            '\u2082', # '\N{SUBSCRIPT TWO}', category 'No'
            '\u32b4', # '\N{CIRCLED NUMBER THIRTY NINE}', category 'No'
            ]
        for x in not_decimal_digits:
            self.assertIsNone(re.match('^\d$', x))

    def test_empty_array(self):
        # SF buf 1647541
        import array
        for typecode in 'bBuhHiIlLfd':
            a = array.array(typecode)
            self.assertEqual(re.compile(b"bla").match(a), None)
            self.assertEqual(re.compile(b"").match(a).groups(), ())

    def test_inline_flags(self):
        # Bug #1700
        upper_char = chr(0x1ea0) # Latin Capital Letter A with Dot Bellow
        lower_char = chr(0x1ea1) # Latin Small Letter A with Dot Bellow

        p = re.compile(upper_char, re.I | re.U)
        q = p.match(lower_char)
        self.assertNotEqual(q, None)

        p = re.compile(lower_char, re.I | re.U)
        q = p.match(upper_char)
        self.assertNotEqual(q, None)

        p = re.compile('(?i)' + upper_char, re.U)
        q = p.match(lower_char)
        self.assertNotEqual(q, None)

        p = re.compile('(?i)' + lower_char, re.U)
        q = p.match(upper_char)
        self.assertNotEqual(q, None)

        p = re.compile('(?iu)' + upper_char)
        q = p.match(lower_char)
        self.assertNotEqual(q, None)

        p = re.compile('(?iu)' + lower_char)
        q = p.match(upper_char)
        self.assertNotEqual(q, None)

    def test_dollar_matches_twice(self):
        "$ matches the end of string, and just before the terminating \n"
        pattern = re.compile('$')
        self.assertEqual(pattern.sub('#', 'a\nb\n'), 'a\nb#\n#')
        self.assertEqual(pattern.sub('#', 'a\nb\nc'), 'a\nb\nc#')
        self.assertEqual(pattern.sub('#', '\n'), '#\n#')

        pattern = re.compile('$', re.MULTILINE)
        self.assertEqual(pattern.sub('#', 'a\nb\n' ), 'a#\nb#\n#' )
        self.assertEqual(pattern.sub('#', 'a\nb\nc'), 'a#\nb#\nc#')
        self.assertEqual(pattern.sub('#', '\n'), '#\n#')

    def test_bytes_str_mixing(self):
        # Mixing str and bytes is disallowed
        pat = re.compile('.')
        bpat = re.compile(b'.')
        self.assertRaises(TypeError, pat.match, b'b')
        self.assertRaises(TypeError, bpat.match, 'b')
        self.assertRaises(TypeError, pat.sub, b'b', 'c')
        self.assertRaises(TypeError, pat.sub, 'b', b'c')
        self.assertRaises(TypeError, pat.sub, b'b', b'c')
        self.assertRaises(TypeError, bpat.sub, b'b', 'c')
        self.assertRaises(TypeError, bpat.sub, 'b', b'c')
        self.assertRaises(TypeError, bpat.sub, 'b', 'c')

    def test_ascii_and_unicode_flag(self):
        # String patterns
        for flags in (0, re.UNICODE):
            pat = re.compile('\xc0', flags | re.IGNORECASE)
            self.assertNotEqual(pat.match('\xe0'), None)
            pat = re.compile('\w', flags)
            self.assertNotEqual(pat.match('\xe0'), None)
        pat = re.compile('\xc0', re.ASCII | re.IGNORECASE)
        self.assertEqual(pat.match('\xe0'), None)
        pat = re.compile('(?a)\xc0', re.IGNORECASE)
        self.assertEqual(pat.match('\xe0'), None)
        pat = re.compile('\w', re.ASCII)
        self.assertEqual(pat.match('\xe0'), None)
        pat = re.compile('(?a)\w')
        self.assertEqual(pat.match('\xe0'), None)
        # Bytes patterns
        for flags in (0, re.ASCII):
            pat = re.compile(b'\xc0', re.IGNORECASE)
            self.assertEqual(pat.match(b'\xe0'), None)
            pat = re.compile(b'\w')
            self.assertEqual(pat.match(b'\xe0'), None)
        # Incompatibilities
        self.assertRaises(ValueError, re.compile, b'\w', re.UNICODE)
        self.assertRaises(ValueError, re.compile, b'(?u)\w')
        self.assertRaises(ValueError, re.compile, '\w', re.UNICODE | re.ASCII)
        self.assertRaises(ValueError, re.compile, '(?u)\w', re.ASCII)
        self.assertRaises(ValueError, re.compile, '(?a)\w', re.UNICODE)
        self.assertRaises(ValueError, re.compile, '(?au)\w')


def run_re_tests():
    from test.re_tests import benchmarks, tests, SUCCEED, FAIL, SYNTAX_ERROR
    if verbose:
        print('Running re_tests test suite')
    else:
        # To save time, only run the first and last 10 tests
        #tests = tests[:10] + tests[-10:]
        pass

    for t in tests:
        sys.stdout.flush()
        pattern = s = outcome = repl = expected = None
        if len(t) == 5:
            pattern, s, outcome, repl, expected = t
        elif len(t) == 3:
            pattern, s, outcome = t
        else:
            raise ValueError('Test tuples should have 3 or 5 fields', t)

        try:
            obj = re.compile(pattern)
        except re.error:
            if outcome == SYNTAX_ERROR: pass  # Expected a syntax error
            else:
                print('=== Syntax error:', t)
        except KeyboardInterrupt: raise KeyboardInterrupt
        except:
            print('*** Unexpected error ***', t)
            if verbose:
                traceback.print_exc(file=sys.stdout)
        else:
            try:
                result = obj.search(s)
            except re.error as msg:
                print('=== Unexpected exception', t, repr(msg))
            if outcome == SYNTAX_ERROR:
                # This should have been a syntax error; forget it.
                pass
            elif outcome == FAIL:
                if result is None: pass   # No match, as expected
                else: print('=== Succeeded incorrectly', t)
            elif outcome == SUCCEED:
                if result is not None:
                    # Matched, as expected, so now we compute the
                    # result string and compare it to our expected result.
                    start, end = result.span(0)
                    vardict={'found': result.group(0),
                             'groups': result.group(),
                             'flags': result.re.flags}
                    for i in range(1, 100):
                        try:
                            gi = result.group(i)
                            # Special hack because else the string concat fails:
                            if gi is None:
                                gi = "None"
                        except IndexError:
                            gi = "Error"
                        vardict['g%d' % i] = gi
                    for i in result.re.groupindex.keys():
                        try:
                            gi = result.group(i)
                            if gi is None:
                                gi = "None"
                        except IndexError:
                            gi = "Error"
                        vardict[i] = gi
                    repl = eval(repl, vardict)
                    if repl != expected:
                        print('=== grouping error', t, end=' ')
                        print(repr(repl) + ' should be ' + repr(expected))
                else:
                    print('=== Failed incorrectly', t)

                # Try the match with both pattern and string converted to
                # bytes, and check that it still succeeds.
                try:
                    bpat = bytes(pattern, "ascii")
                    bs = bytes(s, "ascii")
                except UnicodeEncodeError:
                    # skip non-ascii tests
                    pass
                else:
                    try:
                        bpat = re.compile(bpat)
                    except Exception:
                        print('=== Fails on bytes pattern compile', t)
                        if verbose:
                            traceback.print_exc(file=sys.stdout)
                    else:
                        bytes_result = bpat.search(bs)
                        if bytes_result is None:
                            print('=== Fails on bytes pattern match', t)

                # Try the match with the search area limited to the extent
                # of the match and see if it still succeeds.  \B will
                # break (because it won't match at the end or start of a
                # string), so we'll ignore patterns that feature it.

                if pattern[:2] != '\\B' and pattern[-2:] != '\\B' \
                               and result is not None:
                    obj = re.compile(pattern)
                    result = obj.search(s, result.start(0), result.end(0) + 1)
                    if result is None:
                        print('=== Failed on range-limited match', t)

                # Try the match with IGNORECASE enabled, and check that it
                # still succeeds.
                obj = re.compile(pattern, re.IGNORECASE)
                result = obj.search(s)
                if result is None:
                    print('=== Fails on case-insensitive match', t)

                # Try the match with LOCALE enabled, and check that it
                # still succeeds.
                if '(?u)' not in pattern:
                    obj = re.compile(pattern, re.LOCALE)
                    result = obj.search(s)
                    if result is None:
                        print('=== Fails on locale-sensitive match', t)

                # Try the match with UNICODE locale enabled, and check
                # that it still succeeds.
                obj = re.compile(pattern, re.UNICODE)
                result = obj.search(s)
                if result is None:
                    print('=== Fails on unicode-sensitive match', t)

def test_main():
    run_unittest(ReTests)
    run_re_tests()

if __name__ == "__main__":
    test_main()