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v0.5.1
https://github.com/python/cpython
09 December 2020, 11:06:31 UTC
Revision 9eb3d5463976068900e94b860ced7e035885835c authored by Steve Dower on 21 August 2019, 22:52:42 UTC, committed by GitHub on 21 August 2019, 22:52:42 UTC 
bpo-37834: Normalise handling of reparse points on Windows (GH-15370)
 
bpo-37834: Normalise handling of reparse points on Windows
* ntpath.realpath() and nt.stat() will traverse all supported reparse points (previously was mixed)
* nt.lstat() will let the OS traverse reparse points that are not name surrogates (previously would not traverse any reparse point)
* nt.[l]stat() will only set S_IFLNK for symlinks (previous behaviour)
* nt.readlink() will read destinations for symlinks and junction points only

bpo-1311: os.path.exists('nul') now returns True on Windows
* nt.stat('nul').st_mode is now S_IFCHR (previously was an error)
1 parent c30c869
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Tip revision: 9eb3d5463976068900e94b860ced7e035885835c authored by Steve Dower on 21 August 2019, 22:52:42 UTC
bpo-37834: Normalise handling of reparse points on Windows (GH-15370)
Tip revision: 9eb3d54
test_typechecks.py 
"""Unit tests for __instancecheck__ and __subclasscheck__."""

import unittest


class ABC(type):

    def __instancecheck__(cls, inst):
        """Implement isinstance(inst, cls)."""
        return any(cls.__subclasscheck__(c)
                   for c in {type(inst), inst.__class__})

    def __subclasscheck__(cls, sub):
        """Implement issubclass(sub, cls)."""
        candidates = cls.__dict__.get("__subclass__", set()) | {cls}
        return any(c in candidates for c in sub.mro())


class Integer(metaclass=ABC):
    __subclass__ = {int}


class SubInt(Integer):
    pass


class TypeChecksTest(unittest.TestCase):

    def testIsSubclassInternal(self):
        self.assertEqual(Integer.__subclasscheck__(int), True)
        self.assertEqual(Integer.__subclasscheck__(float), False)

    def testIsSubclassBuiltin(self):
        self.assertEqual(issubclass(int, Integer), True)
        self.assertEqual(issubclass(int, (Integer,)), True)
        self.assertEqual(issubclass(float, Integer), False)
        self.assertEqual(issubclass(float, (Integer,)), False)

    def testIsInstanceBuiltin(self):
        self.assertEqual(isinstance(42, Integer), True)
        self.assertEqual(isinstance(42, (Integer,)), True)
        self.assertEqual(isinstance(3.14, Integer), False)
        self.assertEqual(isinstance(3.14, (Integer,)), False)

    def testIsInstanceActual(self):
        self.assertEqual(isinstance(Integer(), Integer), True)
        self.assertEqual(isinstance(Integer(), (Integer,)), True)

    def testIsSubclassActual(self):
        self.assertEqual(issubclass(Integer, Integer), True)
        self.assertEqual(issubclass(Integer, (Integer,)), True)

    def testSubclassBehavior(self):
        self.assertEqual(issubclass(SubInt, Integer), True)
        self.assertEqual(issubclass(SubInt, (Integer,)), True)
        self.assertEqual(issubclass(SubInt, SubInt), True)
        self.assertEqual(issubclass(SubInt, (SubInt,)), True)
        self.assertEqual(issubclass(Integer, SubInt), False)
        self.assertEqual(issubclass(Integer, (SubInt,)), False)
        self.assertEqual(issubclass(int, SubInt), False)
        self.assertEqual(issubclass(int, (SubInt,)), False)
        self.assertEqual(isinstance(SubInt(), Integer), True)
        self.assertEqual(isinstance(SubInt(), (Integer,)), True)
        self.assertEqual(isinstance(SubInt(), SubInt), True)
        self.assertEqual(isinstance(SubInt(), (SubInt,)), True)
        self.assertEqual(isinstance(42, SubInt), False)
        self.assertEqual(isinstance(42, (SubInt,)), False)


if __name__ == "__main__":
    unittest.main()
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