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bpo-34294: re module, fix wrong capturing groups in rare cases. (GH-11546)

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Need to reset capturing groups between two SRE(match) callings in loops, this fixes wrong capturing groups in rare cases.

Also add a missing index in re.rst.
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animalize 2019-02-18 21:26:37 +08:00 • committed by Serhiy Storchaka
parent 02c04f26df
commit 4a7f44a2ed
5 changed files with 49 additions and 1 deletions
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34
Lib/test/test_re.py
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@ -2067,6 +2067,40 @@ ELSE
self.assertEqual(m.group(), b'xyz')
self.assertEqual(m2.group(), b'')
def test_bug_34294(self):
# Issue 34294: wrong capturing groups
# exists since Python 2
s = "a\tx"
p = r"\b(?=(\t)|(x))x"
self.assertEqual(re.search(p, s).groups(), (None, 'x'))
# introduced in Python 3.7.0
s = "ab"
p = r"(?=(.)(.)?)"
self.assertEqual(re.findall(p, s),
[('a', 'b'), ('b', '')])
self.assertEqual([m.groups() for m in re.finditer(p, s)],
[('a', 'b'), ('b', None)])
# test-cases provided by issue34294, introduced in Python 3.7.0
p = r"(?=<(?P<tag>\w+)/?>(?:(?P<text>.+?)</(?P=tag)>)?)"
s = "<test><foo2/></test>"
self.assertEqual(re.findall(p, s),
[('test', '<foo2/>'), ('foo2', '')])
self.assertEqual([m.groupdict() for m in re.finditer(p, s)],
[{'tag': 'test', 'text': '<foo2/>'},
{'tag': 'foo2', 'text': None}])
s = "<test>Hello</test><foo/>"
self.assertEqual([m.groupdict() for m in re.finditer(p, s)],
[{'tag': 'test', 'text': 'Hello'},
{'tag': 'foo', 'text': None}])
s = "<test>Hello</test><foo/><foo/>"
self.assertEqual([m.groupdict() for m in re.finditer(p, s)],
[{'tag': 'test', 'text': 'Hello'},
{'tag': 'foo', 'text': None},
{'tag': 'foo', 'text': None}])
class PatternReprTests(unittest.TestCase):
def check(self, pattern, expected):