def test_registration_builtins(self):
class A(metaclass=abc.ABCMeta):
pass
A.register(int)
self.assertIsInstance(42, A)
self.assertIsInstance(42, (A,))
self.assertTrue(issubclass(int, A))
self.assertTrue(issubclass(int, (A,)))
class B(A):
pass
B.register(str)
class C(str): pass
self.assertIsInstance("", A)
self.assertIsInstance("", (A,))
self.assertTrue(issubclass(str, A))
self.assertTrue(issubclass(str, (A,)))
self.assertTrue(issubclass(C, A))
self.assertTrue(issubclass(C, (A,)))
python类ABCMeta()的实例源码
def test_slots_descriptor(self):
# Issue2115: slot descriptors did not correctly check
# the type of the given object
import abc
class MyABC(metaclass=abc.ABCMeta):
__slots__ = "a"
class Unrelated(object):
pass
MyABC.register(Unrelated)
u = Unrelated()
self.assertIsInstance(u, MyABC)
# This used to crash
self.assertRaises(TypeError, MyABC.a.__set__, u, 3)
def test_registration_basics(self):
class A:
__metaclass__ = abc.ABCMeta
class B(object):
pass
b = B()
self.assertFalse(issubclass(B, A))
self.assertFalse(issubclass(B, (A,)))
self.assertNotIsInstance(b, A)
self.assertNotIsInstance(b, (A,))
A.register(B)
self.assertTrue(issubclass(B, A))
self.assertTrue(issubclass(B, (A,)))
self.assertIsInstance(b, A)
self.assertIsInstance(b, (A,))
class C(B):
pass
c = C()
self.assertTrue(issubclass(C, A))
self.assertTrue(issubclass(C, (A,)))
self.assertIsInstance(c, A)
self.assertIsInstance(c, (A,))
def test_registration_edge_cases(self):
class A:
__metaclass__ = abc.ABCMeta
A.register(A) # should pass silently
class A1(A):
pass
self.assertRaises(RuntimeError, A1.register, A) # cycles not allowed
class B(object):
pass
A1.register(B) # ok
A1.register(B) # should pass silently
class C(A):
pass
A.register(C) # should pass silently
self.assertRaises(RuntimeError, C.register, A) # cycles not allowed
C.register(B) # ok
def test_slots_descriptor(self):
# Issue2115: slot descriptors did not correctly check
# the type of the given object
import abc
class MyABC:
__metaclass__ = abc.ABCMeta
__slots__ = "a"
class Unrelated(object):
pass
MyABC.register(Unrelated)
u = Unrelated()
self.assertIsInstance(u, MyABC)
# This used to crash
self.assertRaises(TypeError, MyABC.a.__set__, u, 3)
def test_abstractproperty_basics(self):
@abc.abstractproperty
def foo(self): pass
self.assertTrue(foo.__isabstractmethod__)
def bar(self): pass
self.assertFalse(hasattr(bar, "__isabstractmethod__"))
class C(metaclass=abc.ABCMeta):
@abc.abstractproperty
def foo(self): return 3
self.assertRaises(TypeError, C)
class D(C):
@property
def foo(self): return super().foo
self.assertEqual(D().foo, 3)
self.assertFalse(getattr(D.foo, "__isabstractmethod__", False))
def test_abstractclassmethod_basics(self):
@abc.abstractclassmethod
def foo(cls): pass
self.assertTrue(foo.__isabstractmethod__)
@classmethod
def bar(cls): pass
self.assertFalse(getattr(bar, "__isabstractmethod__", False))
class C(metaclass=abc.ABCMeta):
@abc.abstractclassmethod
def foo(cls): return cls.__name__
self.assertRaises(TypeError, C)
class D(C):
@classmethod
def foo(cls): return super().foo()
self.assertEqual(D.foo(), 'D')
self.assertEqual(D().foo(), 'D')
def test_abstractstaticmethod_basics(self):
@abc.abstractstaticmethod
def foo(): pass
self.assertTrue(foo.__isabstractmethod__)
@staticmethod
def bar(): pass
self.assertFalse(getattr(bar, "__isabstractmethod__", False))
class C(metaclass=abc.ABCMeta):
@abc.abstractstaticmethod
def foo(): return 3
self.assertRaises(TypeError, C)
class D(C):
@staticmethod
def foo(): return 4
self.assertEqual(D.foo(), 4)
self.assertEqual(D().foo(), 4)
def test_abstractproperty_basics(self):
@property
@abc.abstractmethod
def foo(self): pass
self.assertTrue(foo.__isabstractmethod__)
def bar(self): pass
self.assertFalse(getattr(bar, "__isabstractmethod__", False))
class C(metaclass=abc.ABCMeta):
@property
@abc.abstractmethod
def foo(self): return 3
self.assertRaises(TypeError, C)
class D(C):
@C.foo.getter
def foo(self): return super().foo
self.assertEqual(D().foo, 3)
def test_abstractstaticmethod_basics(self):
@staticmethod
@abc.abstractmethod
def foo(): pass
self.assertTrue(foo.__isabstractmethod__)
@staticmethod
def bar(): pass
self.assertFalse(getattr(bar, "__isabstractmethod__", False))
class C(metaclass=abc.ABCMeta):
@staticmethod
@abc.abstractmethod
def foo(): return 3
self.assertRaises(TypeError, C)
class D(C):
@staticmethod
def foo(): return 4
self.assertEqual(D.foo(), 4)
self.assertEqual(D().foo(), 4)
def test_register_as_class_deco(self):
class A(metaclass=abc.ABCMeta):
pass
@A.register
class B(object):
pass
b = B()
self.assertTrue(issubclass(B, A))
self.assertTrue(issubclass(B, (A,)))
self.assertIsInstance(b, A)
self.assertIsInstance(b, (A,))
@A.register
class C(B):
pass
c = C()
self.assertTrue(issubclass(C, A))
self.assertTrue(issubclass(C, (A,)))
self.assertIsInstance(c, A)
self.assertIsInstance(c, (A,))
self.assertIs(C, A.register(C))
def test_registration_builtins(self):
class A(metaclass=abc.ABCMeta):
pass
A.register(int)
self.assertIsInstance(42, A)
self.assertIsInstance(42, (A,))
self.assertTrue(issubclass(int, A))
self.assertTrue(issubclass(int, (A,)))
class B(A):
pass
B.register(str)
class C(str): pass
self.assertIsInstance("", A)
self.assertIsInstance("", (A,))
self.assertTrue(issubclass(str, A))
self.assertTrue(issubclass(str, (A,)))
self.assertTrue(issubclass(C, A))
self.assertTrue(issubclass(C, (A,)))
def test_registration_edge_cases(self):
class A(metaclass=abc.ABCMeta):
pass
A.register(A) # should pass silently
class A1(A):
pass
self.assertRaises(RuntimeError, A1.register, A) # cycles not allowed
class B(object):
pass
A1.register(B) # ok
A1.register(B) # should pass silently
class C(A):
pass
A.register(C) # should pass silently
self.assertRaises(RuntimeError, C.register, A) # cycles not allowed
C.register(B) # ok
def test_slots_descriptor(self):
# Issue2115: slot descriptors did not correctly check
# the type of the given object
import abc
class MyABC(metaclass=abc.ABCMeta):
__slots__ = "a"
class Unrelated(object):
pass
MyABC.register(Unrelated)
u = Unrelated()
self.assertIsInstance(u, MyABC)
# This used to crash
self.assertRaises(TypeError, MyABC.a.__set__, u, 3)
def test_registration_basics(self):
class A:
__metaclass__ = abc.ABCMeta
class B(object):
pass
b = B()
self.assertFalse(issubclass(B, A))
self.assertFalse(issubclass(B, (A,)))
self.assertNotIsInstance(b, A)
self.assertNotIsInstance(b, (A,))
A.register(B)
self.assertTrue(issubclass(B, A))
self.assertTrue(issubclass(B, (A,)))
self.assertIsInstance(b, A)
self.assertIsInstance(b, (A,))
class C(B):
pass
c = C()
self.assertTrue(issubclass(C, A))
self.assertTrue(issubclass(C, (A,)))
self.assertIsInstance(c, A)
self.assertIsInstance(c, (A,))
def test_registration_edge_cases(self):
class A:
__metaclass__ = abc.ABCMeta
A.register(A) # should pass silently
class A1(A):
pass
self.assertRaises(RuntimeError, A1.register, A) # cycles not allowed
class B(object):
pass
A1.register(B) # ok
A1.register(B) # should pass silently
class C(A):
pass
A.register(C) # should pass silently
self.assertRaises(RuntimeError, C.register, A) # cycles not allowed
C.register(B) # ok
def test_slots_descriptor(self):
# Issue2115: slot descriptors did not correctly check
# the type of the given object
import abc
class MyABC:
__metaclass__ = abc.ABCMeta
__slots__ = "a"
class Unrelated(object):
pass
MyABC.register(Unrelated)
u = Unrelated()
self.assertIsInstance(u, MyABC)
# This used to crash
self.assertRaises(TypeError, MyABC.a.__set__, u, 3)
def mk_awaitable():
from abc import abstractmethod, ABCMeta
@abstractmethod
def __await__(self):
yield
@classmethod
def __subclasshook__(cls, C):
if cls is Awaitable:
for B in C.__mro__:
if '__await__' in B.__dict__:
if B.__dict__['__await__']:
return True
break
return NotImplemented
# calling metaclass directly as syntax differs in Py2/Py3
Awaitable = ABCMeta('Awaitable', (), {
'__slots__': (),
'__await__': __await__,
'__subclasshook__': __subclasshook__,
})
return Awaitable
def _type_is_pure_interface(cls):
""" Return True if cls is a pure interface or an empty ABC class"""
if cls is object:
return False
if hasattr(cls, '_pi'):
return cls._pi.type_is_pure_interface
if issubclass(type(cls), abc.ABCMeta):
for attr, value in six.iteritems(cls.__dict__):
if _builtin_attrs(attr):
continue
if callable(value):
if not _is_empty_function(value):
return False
elif isinstance(value, property):
for func in (value.fget, value.fset, value.fdel):
if func is not None and not _is_empty_function(func):
return False
return True
return False
def test_abstractproperty_basics(self):
@abc.abstractproperty
def foo(self): pass
self.assertTrue(foo.__isabstractmethod__)
def bar(self): pass
self.assertFalse(hasattr(bar, "__isabstractmethod__"))
class C(metaclass=abc.ABCMeta):
@abc.abstractproperty
def foo(self): return 3
self.assertRaises(TypeError, C)
class D(C):
@property
def foo(self): return super().foo
self.assertEqual(D().foo, 3)
self.assertFalse(getattr(D.foo, "__isabstractmethod__", False))
