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More updates from upstream typing.py

This commit is contained in:
Guido van Rossum 2016-10-03 08:40:50 -07:00
parent cc164232aa
commit b47c9d29d7
2 changed files with 117 additions and 73 deletions
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81
Lib/test/test_typing.py
View File

@ -202,10 +202,13 @@ class UnionTests(BaseTestCase):
def test_union_any(self):
u = Union[Any]
self.assertEqual(u, Any)
u = Union[int, Any]
self.assertEqual(u, Any)
u = Union[Any, int]
self.assertEqual(u, Any)
u1 = Union[int, Any]
u2 = Union[Any, int]
u3 = Union[Any, object]
self.assertEqual(u1, u2)
self.assertNotEqual(u1, Any)
self.assertNotEqual(u2, Any)
self.assertNotEqual(u3, Any)
def test_union_object(self):
u = Union[object]
@ -215,12 +218,6 @@ class UnionTests(BaseTestCase):
u = Union[object, int]
self.assertEqual(u, object)
def test_union_any_object(self):
u = Union[object, Any]
self.assertEqual(u, Any)
u = Union[Any, object]
self.assertEqual(u, Any)
def test_unordered(self):
u1 = Union[int, float]
u2 = Union[float, int]
@ -600,36 +597,32 @@ class GenericTests(BaseTestCase):
self.assertNotIsInstance({}, MyMapping)
self.assertNotIsSubclass(dict, MyMapping)
def test_multiple_abc_bases(self):
def test_abc_bases(self):
class MM(MutableMapping[str, str]):
def __getitem__(self, k):
return None
def __setitem__(self, k, v):
pass
def __delitem__(self, k):
pass
def __iter__(self):
return iter(())
def __len__(self):
return 0
# this should just work
MM().update()
self.assertIsInstance(MM(), collections_abc.MutableMapping)
self.assertIsInstance(MM(), MutableMapping)
self.assertNotIsInstance(MM(), List)
self.assertNotIsInstance({}, MM)
def test_multiple_bases(self):
class MM1(MutableMapping[str, str], collections_abc.MutableMapping):
def __getitem__(self, k):
return None
def __setitem__(self, k, v):
pass
def __delitem__(self, k):
pass
def __iter__(self):
return iter(())
def __len__(self):
return 0
with self.assertRaises(TypeError):
# consistent MRO not possible
class MM2(collections_abc.MutableMapping, MutableMapping[str, str]):
def __getitem__(self, k):
return None
def __setitem__(self, k, v):
pass
def __delitem__(self, k):
pass
def __iter__(self):
return iter(())
def __len__(self):
return 0
# these two should just work
MM1().update()
MM2().update()
self.assertIsInstance(MM1(), collections_abc.MutableMapping)
self.assertIsInstance(MM1(), MutableMapping)
self.assertIsInstance(MM2(), collections_abc.MutableMapping)
self.assertIsInstance(MM2(), MutableMapping)
def test_pickle(self):
global C # pickle wants to reference the class by name
@ -1380,12 +1373,28 @@ class CollectionsAbcTests(BaseTestCase):
MMA()
class MMC(MMA):
def __getitem__(self, k):
return None
def __setitem__(self, k, v):
pass
def __delitem__(self, k):
pass
def __iter__(self):
return iter(())
def __len__(self):
return 0
self.assertEqual(len(MMC()), 0)
class MMB(typing.MutableMapping[KT, VT]):
def __getitem__(self, k):
return None
def __setitem__(self, k, v):
pass
def __delitem__(self, k):
pass
def __iter__(self):
return iter(())
def __len__(self):
return 0

105
Lib/typing.py
View File

@ -143,7 +143,6 @@ class _TypingBase(metaclass=TypingMeta, _root=True):
__slots__ = ()
def __init__(self, *args, **kwds):
pass
@ -158,7 +157,7 @@ class _TypingBase(metaclass=TypingMeta, _root=True):
isinstance(args[1], tuple)):
# Close enough.
raise TypeError("Cannot subclass %r" % cls)
return object.__new__(cls)
return super().__new__(cls)
# Things that are not classes also need these.
def _eval_type(self, globalns, localns):
@ -177,7 +176,11 @@ class _TypingBase(metaclass=TypingMeta, _root=True):
class _FinalTypingBase(_TypingBase, _root=True):
"""Mix-in class to prevent instantiation."""
"""Mix-in class to prevent instantiation.
Prevents instantiation unless _root=True is given in class call.
It is used to create pseudo-singleton instances Any, Union, Tuple, etc.
"""
__slots__ = ()
@ -273,7 +276,7 @@ class _TypeAlias(_TypingBase, _root=True):
assert isinstance(name, str), repr(name)
assert isinstance(impl_type, type), repr(impl_type)
assert not isinstance(impl_type, TypingMeta), repr(impl_type)
assert isinstance(type_var, (type, _TypingBase))
assert isinstance(type_var, (type, _TypingBase)), repr(type_var)
self.name = name
self.type_var = type_var
self.impl_type = impl_type
@ -375,9 +378,13 @@ def _type_repr(obj):
class _Any(_FinalTypingBase, _root=True):
"""Special type indicating an unconstrained type.
- Any object is an instance of Any.
- Any class is a subclass of Any.
- As a special case, Any and object are subclasses of each other.
- Any is compatible with every type.
- Any assumed to have all methods.
- All values assumed to be instances of Any.
Note that all the above statements are true from the point of view of
static type checkers. At runtime, Any should not be used with instance
or class checks.
"""
__slots__ = ()
@ -502,7 +509,7 @@ def _tp_cache(func):
try:
return cached(*args, **kwds)
except TypeError:
pass # Do not duplicate real errors.
pass # All real errors (not unhashable args) are raised below.
return func(*args, **kwds)
return inner
@ -542,16 +549,10 @@ class _Union(_FinalTypingBase, _root=True):
Union[Manager, int, Employee] == Union[int, Employee]
Union[Employee, Manager] == Employee
- Corollary: if Any is present it is the sole survivor, e.g.::
Union[int, Any] == Any
- Similar for object::
Union[int, object] == object
- To cut a tie: Union[object, Any] == Union[Any, object] == Any.
- You cannot subclass or instantiate a union.
- You cannot write Union[X][Y] (what would it mean?).
@ -589,14 +590,11 @@ class _Union(_FinalTypingBase, _root=True):
assert not all_params, all_params
# Weed out subclasses.
# E.g. Union[int, Employee, Manager] == Union[int, Employee].
# If Any or object is present it will be the sole survivor.
# If both Any and object are present, Any wins.
# Never discard type variables, except against Any.
# If object is present it will be sole survivor among proper classes.
# Never discard type variables.
# (In particular, Union[str, AnyStr] != AnyStr.)
all_params = set(params)
for t1 in params:
if t1 is Any:
return Any
if not isinstance(t1, type):
continue
if any(isinstance(t2, type) and issubclass(t1, t2)
@ -662,7 +660,7 @@ Union = _Union(_root=True)
class _Optional(_FinalTypingBase, _root=True):
"""Optional type.
Optional[X] is equivalent to Union[X, type(None)].
Optional[X] is equivalent to Union[X, None].
"""
__slots__ = ()
@ -894,11 +892,55 @@ def _next_in_mro(cls):
return next_in_mro
def _valid_for_check(cls):
if cls is Generic:
raise TypeError("Class %r cannot be used with class "
"or instance checks" % cls)
if (cls.__origin__ is not None and
sys._getframe(3).f_globals['__name__'] not in ['abc', 'functools']):
raise TypeError("Parameterized generics cannot be used with class "
"or instance checks")
def _make_subclasshook(cls):
"""Construct a __subclasshook__ callable that incorporates
the associated __extra__ class in subclass checks performed
against cls.
"""
if isinstance(cls.__extra__, abc.ABCMeta):
# The logic mirrors that of ABCMeta.__subclasscheck__.
# Registered classes need not be checked here because
# cls and its extra share the same _abc_registry.
def __extrahook__(subclass):
_valid_for_check(cls)
res = cls.__extra__.__subclasshook__(subclass)
if res is not NotImplemented:
return res
if cls.__extra__ in subclass.__mro__:
return True
for scls in cls.__extra__.__subclasses__():
if isinstance(scls, GenericMeta):
continue
if issubclass(subclass, scls):
return True
return NotImplemented
else:
# For non-ABC extras we'll just call issubclass().
def __extrahook__(subclass):
_valid_for_check(cls)
if cls.__extra__ and issubclass(subclass, cls.__extra__):
return True
return NotImplemented
return __extrahook__
class GenericMeta(TypingMeta, abc.ABCMeta):
"""Metaclass for generic types."""
def __new__(cls, name, bases, namespace,
tvars=None, args=None, origin=None, extra=None):
if extra is not None and type(extra) is abc.ABCMeta and extra not in bases:
bases = (extra,) + bases
self = super().__new__(cls, name, bases, namespace, _root=True)
if tvars is not None:
@ -947,6 +989,13 @@ class GenericMeta(TypingMeta, abc.ABCMeta):
self.__extra__ = extra
# Speed hack (https://github.com/python/typing/issues/196).
self.__next_in_mro__ = _next_in_mro(self)
# This allows unparameterized generic collections to be used
# with issubclass() and isinstance() in the same way as their
# collections.abc counterparts (e.g., isinstance([], Iterable)).
self.__subclasshook__ = _make_subclasshook(self)
if isinstance(extra, abc.ABCMeta):
self._abc_registry = extra._abc_registry
return self
def _get_type_vars(self, tvars):
@ -1032,21 +1081,7 @@ class GenericMeta(TypingMeta, abc.ABCMeta):
# latter, we must extend __instancecheck__ too. For simplicity
# we just skip the cache check -- instance checks for generic
# classes are supposed to be rare anyways.
return self.__subclasscheck__(instance.__class__)
def __subclasscheck__(self, cls):
if self is Generic:
raise TypeError("Class %r cannot be used with class "
"or instance checks" % self)
if (self.__origin__ is not None and
sys._getframe(1).f_globals['__name__'] != 'abc'):
raise TypeError("Parameterized generics cannot be used with class "
"or instance checks")
if super().__subclasscheck__(cls):
return True
if self.__extra__ is not None:
return issubclass(cls, self.__extra__)
return False
return issubclass(instance.__class__, self)
# Prevent checks for Generic to crash when defining Generic.