lib-python.2.7.test.test_typechecks.py Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of jython Show documentation
Show all versions of jython Show documentation
Jython is an implementation of the high-level, dynamic, object-oriented
language Python written in 100% Pure Java, and seamlessly integrated with
the Java platform. It thus allows you to run Python on any Java platform.
"""Unit tests for __instancecheck__ and __subclasscheck__."""
import unittest
from test import test_support
class ABC(type):
def __instancecheck__(cls, inst):
"""Implement isinstance(inst, cls)."""
return any(cls.__subclasscheck__(c)
for c in set([type(inst), inst.__class__]))
def __subclasscheck__(cls, sub):
"""Implement issubclass(sub, cls)."""
candidates = cls.__dict__.get("__subclass__", set()) | set([cls])
return any(c in candidates for c in sub.mro())
class Integer:
__metaclass__ = ABC
__subclass__ = set([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)
def test_oldstyle(self):
# These should just be ignored.
class X:
def __instancecheck__(self, inst):
return True
def __subclasscheck__(self, cls):
return True
class Sub(X): pass
self.assertNotIsInstance(3, X)
self.assertIsInstance(X(), X)
self.assertFalse(issubclass(int, X))
self.assertTrue(issubclass(Sub, X))
def test_main():
test_support.run_unittest(TypeChecksTest)
if __name__ == "__main__":
unittest.main()