diff options
Diffstat (limited to 'Lib/_collections_abc.py')
| -rw-r--r-- | Lib/_collections_abc.py | 111 |
1 files changed, 60 insertions, 51 deletions
diff --git a/Lib/_collections_abc.py b/Lib/_collections_abc.py index fc9c9f1cc1..f035970a8e 100644 --- a/Lib/_collections_abc.py +++ b/Lib/_collections_abc.py @@ -10,8 +10,8 @@ from abc import ABCMeta, abstractmethod import sys __all__ = ["Awaitable", "Coroutine", "AsyncIterable", "AsyncIterator", - "Hashable", "Iterable", "Iterator", "Generator", - "Sized", "Container", "Callable", + "Hashable", "Iterable", "Iterator", "Generator", "Reversible", + "Sized", "Container", "Callable", "Collection", "Set", "MutableSet", "Mapping", "MutableMapping", "MappingView", "KeysView", "ItemsView", "ValuesView", @@ -62,6 +62,18 @@ del _coro ### ONE-TRICK PONIES ### +def _check_methods(C, *methods): + mro = C.__mro__ + for method in methods: + for B in mro: + if method in B.__dict__: + if B.__dict__[method] is None: + return NotImplemented + break + else: + return NotImplemented + return True + class Hashable(metaclass=ABCMeta): __slots__ = () @@ -73,11 +85,7 @@ class Hashable(metaclass=ABCMeta): @classmethod def __subclasshook__(cls, C): if cls is Hashable: - for B in C.__mro__: - if "__hash__" in B.__dict__: - if B.__dict__["__hash__"]: - return True - break + return _check_methods(C, "__hash__") return NotImplemented @@ -92,11 +100,7 @@ class Awaitable(metaclass=ABCMeta): @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 _check_methods(C, "__await__") return NotImplemented @@ -137,14 +141,7 @@ class Coroutine(Awaitable): @classmethod def __subclasshook__(cls, C): if cls is Coroutine: - mro = C.__mro__ - for method in ('__await__', 'send', 'throw', 'close'): - for base in mro: - if method in base.__dict__: - break - else: - return NotImplemented - return True + return _check_methods(C, '__await__', 'send', 'throw', 'close') return NotImplemented @@ -162,8 +159,7 @@ class AsyncIterable(metaclass=ABCMeta): @classmethod def __subclasshook__(cls, C): if cls is AsyncIterable: - if any("__aiter__" in B.__dict__ for B in C.__mro__): - return True + return _check_methods(C, "__aiter__") return NotImplemented @@ -182,9 +178,7 @@ class AsyncIterator(AsyncIterable): @classmethod def __subclasshook__(cls, C): if cls is AsyncIterator: - if (any("__anext__" in B.__dict__ for B in C.__mro__) and - any("__aiter__" in B.__dict__ for B in C.__mro__)): - return True + return _check_methods(C, "__anext__", "__aiter__") return NotImplemented @@ -200,8 +194,7 @@ class Iterable(metaclass=ABCMeta): @classmethod def __subclasshook__(cls, C): if cls is Iterable: - if any("__iter__" in B.__dict__ for B in C.__mro__): - return True + return _check_methods(C, "__iter__") return NotImplemented @@ -220,9 +213,7 @@ class Iterator(Iterable): @classmethod def __subclasshook__(cls, C): if cls is Iterator: - if (any("__next__" in B.__dict__ for B in C.__mro__) and - any("__iter__" in B.__dict__ for B in C.__mro__)): - return True + return _check_methods(C, '__iter__', '__next__') return NotImplemented Iterator.register(bytes_iterator) @@ -240,6 +231,22 @@ Iterator.register(tuple_iterator) Iterator.register(zip_iterator) +class Reversible(Iterable): + + __slots__ = () + + @abstractmethod + def __reversed__(self): + while False: + yield None + + @classmethod + def __subclasshook__(cls, C): + if cls is Reversible: + return _check_methods(C, "__reversed__", "__iter__") + return NotImplemented + + class Generator(Iterator): __slots__ = () @@ -283,17 +290,10 @@ class Generator(Iterator): @classmethod def __subclasshook__(cls, C): if cls is Generator: - mro = C.__mro__ - for method in ('__iter__', '__next__', 'send', 'throw', 'close'): - for base in mro: - if method in base.__dict__: - break - else: - return NotImplemented - return True + return _check_methods(C, '__iter__', '__next__', + 'send', 'throw', 'close') return NotImplemented - Generator.register(generator) @@ -308,8 +308,7 @@ class Sized(metaclass=ABCMeta): @classmethod def __subclasshook__(cls, C): if cls is Sized: - if any("__len__" in B.__dict__ for B in C.__mro__): - return True + return _check_methods(C, "__len__") return NotImplemented @@ -324,10 +323,18 @@ class Container(metaclass=ABCMeta): @classmethod def __subclasshook__(cls, C): if cls is Container: - if any("__contains__" in B.__dict__ for B in C.__mro__): - return True + return _check_methods(C, "__contains__") return NotImplemented +class Collection(Sized, Iterable, Container): + + __slots__ = () + + @classmethod + def __subclasshook__(cls, C): + if cls is Collection: + return _check_methods(C, "__len__", "__iter__", "__contains__") + return NotImplemented class Callable(metaclass=ABCMeta): @@ -340,15 +347,14 @@ class Callable(metaclass=ABCMeta): @classmethod def __subclasshook__(cls, C): if cls is Callable: - if any("__call__" in B.__dict__ for B in C.__mro__): - return True + return _check_methods(C, "__call__") return NotImplemented ### SETS ### -class Set(Sized, Iterable, Container): +class Set(Collection): """A set is a finite, iterable container. @@ -573,7 +579,7 @@ MutableSet.register(set) ### MAPPINGS ### -class Mapping(Sized, Iterable, Container): +class Mapping(Collection): __slots__ = () @@ -621,6 +627,8 @@ class Mapping(Sized, Iterable, Container): return NotImplemented return dict(self.items()) == dict(other.items()) + __reversed__ = None + Mapping.register(mappingproxy) @@ -670,7 +678,7 @@ class ItemsView(MappingView, Set): except KeyError: return False else: - return v == value + return v is value or v == value def __iter__(self): for key in self._mapping: @@ -685,7 +693,8 @@ class ValuesView(MappingView): def __contains__(self, value): for key in self._mapping: - if value == self._mapping[key]: + v = self._mapping[key] + if v is value or v == value: return True return False @@ -794,7 +803,7 @@ MutableMapping.register(dict) ### SEQUENCES ### -class Sequence(Sized, Iterable, Container): +class Sequence(Reversible, Collection): """All the operations on a read-only sequence. @@ -820,7 +829,7 @@ class Sequence(Sized, Iterable, Container): def __contains__(self, value): for v in self: - if v == value: + if v is value or v == value: return True return False |