diff options
Diffstat (limited to 'Lib/typing.py')
-rw-r--r-- | Lib/typing.py | 138 |
1 files changed, 105 insertions, 33 deletions
diff --git a/Lib/typing.py b/Lib/typing.py index c9e3417..efe358f 100644 --- a/Lib/typing.py +++ b/Lib/typing.py @@ -10,6 +10,12 @@ try: import collections.abc as collections_abc except ImportError: import collections as collections_abc # Fallback for PY3.2. +try: + from types import SlotWrapperType, MethodWrapperType, MethodDescriptorType +except ImportError: + SlotWrapperType = type(object.__init__) + MethodWrapperType = type(object().__str__) + MethodDescriptorType = type(str.join) # Please keep __all__ alphabetized within each category. @@ -62,6 +68,7 @@ __all__ = [ 'SupportsRound', # Concrete collection types. + 'Counter', 'Deque', 'Dict', 'DefaultDict', @@ -849,19 +856,6 @@ def _next_in_mro(cls): return next_in_mro -def _valid_for_check(cls): - """An internal helper to prohibit isinstance([1], List[str]) etc.""" - 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 @@ -872,7 +866,6 @@ def _make_subclasshook(cls): # 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 @@ -887,7 +880,6 @@ def _make_subclasshook(cls): 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 @@ -974,6 +966,7 @@ class GenericMeta(TypingMeta, abc.ABCMeta): # remove bare Generic from bases if there are other generic bases if any(isinstance(b, GenericMeta) and b is not Generic for b in bases): bases = tuple(b for b in bases if b is not Generic) + namespace.update({'__origin__': origin, '__extra__': extra}) self = super().__new__(cls, name, bases, namespace, _root=True) self.__parameters__ = tvars @@ -982,8 +975,6 @@ class GenericMeta(TypingMeta, abc.ABCMeta): self.__args__ = tuple(... if a is _TypingEllipsis else () if a is _TypingEmpty else a for a in args) if args else None - self.__origin__ = origin - self.__extra__ = extra # Speed hack (https://github.com/python/typing/issues/196). self.__next_in_mro__ = _next_in_mro(self) # Preserve base classes on subclassing (__bases__ are type erased now). @@ -994,20 +985,56 @@ class GenericMeta(TypingMeta, abc.ABCMeta): # with issubclass() and isinstance() in the same way as their # collections.abc counterparts (e.g., isinstance([], Iterable)). if ( - # allow overriding '__subclasshook__' not in namespace and extra or - hasattr(self.__subclasshook__, '__name__') and - self.__subclasshook__.__name__ == '__extrahook__' + # allow overriding + getattr(self.__subclasshook__, '__name__', '') == '__extrahook__' ): self.__subclasshook__ = _make_subclasshook(self) if isinstance(extra, abc.ABCMeta): self._abc_registry = extra._abc_registry + self._abc_cache = extra._abc_cache + elif origin is not None: + self._abc_registry = origin._abc_registry + self._abc_cache = origin._abc_cache if origin and hasattr(origin, '__qualname__'): # Fix for Python 3.2. self.__qualname__ = origin.__qualname__ - self.__tree_hash__ = hash(self._subs_tree()) if origin else hash((self.__name__,)) + self.__tree_hash__ = (hash(self._subs_tree()) if origin else + super(GenericMeta, self).__hash__()) return self + # _abc_negative_cache and _abc_negative_cache_version + # realised as descriptors, since GenClass[t1, t2, ...] always + # share subclass info with GenClass. + # This is an important memory optimization. + @property + def _abc_negative_cache(self): + if isinstance(self.__extra__, abc.ABCMeta): + return self.__extra__._abc_negative_cache + return _gorg(self)._abc_generic_negative_cache + + @_abc_negative_cache.setter + def _abc_negative_cache(self, value): + if self.__origin__ is None: + if isinstance(self.__extra__, abc.ABCMeta): + self.__extra__._abc_negative_cache = value + else: + self._abc_generic_negative_cache = value + + @property + def _abc_negative_cache_version(self): + if isinstance(self.__extra__, abc.ABCMeta): + return self.__extra__._abc_negative_cache_version + return _gorg(self)._abc_generic_negative_cache_version + + @_abc_negative_cache_version.setter + def _abc_negative_cache_version(self, value): + if self.__origin__ is None: + if isinstance(self.__extra__, abc.ABCMeta): + self.__extra__._abc_negative_cache_version = value + else: + self._abc_generic_negative_cache_version = value + def _get_type_vars(self, tvars): if self.__origin__ and self.__parameters__: _get_type_vars(self.__parameters__, tvars) @@ -1095,8 +1122,10 @@ class GenericMeta(TypingMeta, abc.ABCMeta): _check_generic(self, params) tvars = _type_vars(params) args = params + + prepend = (self,) if self.__origin__ is None else () return self.__class__(self.__name__, - self.__bases__, + prepend + self.__bases__, _no_slots_copy(self.__dict__), tvars=tvars, args=args, @@ -1104,6 +1133,17 @@ class GenericMeta(TypingMeta, abc.ABCMeta): extra=self.__extra__, orig_bases=self.__orig_bases__) + def __subclasscheck__(self, cls): + if self.__origin__ is not None: + if sys._getframe(1).f_globals['__name__'] not in ['abc', 'functools']: + raise TypeError("Parameterized generics cannot be used with class " + "or instance checks") + return False + if self is Generic: + raise TypeError("Class %r cannot be used with class " + "or instance checks" % self) + return super().__subclasscheck__(cls) + def __instancecheck__(self, instance): # Since we extend ABC.__subclasscheck__ and # ABC.__instancecheck__ inlines the cache checking done by the @@ -1398,6 +1438,11 @@ def _get_defaults(func): return res +_allowed_types = (types.FunctionType, types.BuiltinFunctionType, + types.MethodType, types.ModuleType, + SlotWrapperType, MethodWrapperType, MethodDescriptorType) + + def get_type_hints(obj, globalns=None, localns=None): """Return type hints for an object. @@ -1452,12 +1497,7 @@ def get_type_hints(obj, globalns=None, localns=None): hints = getattr(obj, '__annotations__', None) if hints is None: # Return empty annotations for something that _could_ have them. - if ( - isinstance(obj, types.FunctionType) or - isinstance(obj, types.BuiltinFunctionType) or - isinstance(obj, types.MethodType) or - isinstance(obj, types.ModuleType) - ): + if isinstance(obj, _allowed_types): return {} else: raise TypeError('{!r} is not a module, class, method, ' @@ -1824,8 +1864,7 @@ class Deque(collections.deque, MutableSequence[T], extra=collections.deque): def __new__(cls, *args, **kwds): if _geqv(cls, Deque): - raise TypeError("Type Deque cannot be instantiated; " - "use deque() instead") + return collections.deque(*args, **kwds) return _generic_new(collections.deque, cls, *args, **kwds) @@ -1894,11 +1933,35 @@ class DefaultDict(collections.defaultdict, MutableMapping[KT, VT], def __new__(cls, *args, **kwds): if _geqv(cls, DefaultDict): - raise TypeError("Type DefaultDict cannot be instantiated; " - "use collections.defaultdict() instead") + return collections.defaultdict(*args, **kwds) return _generic_new(collections.defaultdict, cls, *args, **kwds) +class Counter(collections.Counter, Dict[T, int], extra=collections.Counter): + + __slots__ = () + + def __new__(cls, *args, **kwds): + if _geqv(cls, Counter): + return collections.Counter(*args, **kwds) + return _generic_new(collections.Counter, cls, *args, **kwds) + + +if hasattr(collections, 'ChainMap'): + # ChainMap only exists in 3.3+ + __all__.append('ChainMap') + + class ChainMap(collections.ChainMap, MutableMapping[KT, VT], + extra=collections.ChainMap): + + __slots__ = () + + def __new__(cls, *args, **kwds): + if _geqv(cls, ChainMap): + return collections.ChainMap(*args, **kwds) + return _generic_new(collections.ChainMap, cls, *args, **kwds) + + # Determine what base class to use for Generator. if hasattr(collections_abc, 'Generator'): # Sufficiently recent versions of 3.5 have a Generator ABC. @@ -1975,6 +2038,13 @@ def _make_nmtuple(name, types): _PY36 = sys.version_info[:2] >= (3, 6) +# attributes prohibited to set in NamedTuple class syntax +_prohibited = ('__new__', '__init__', '__slots__', '__getnewargs__', + '_fields', '_field_defaults', '_field_types', + '_make', '_replace', '_asdict') + +_special = ('__module__', '__name__', '__qualname__', '__annotations__') + class NamedTupleMeta(type): @@ -2002,7 +2072,9 @@ class NamedTupleMeta(type): nm_tpl._field_defaults = defaults_dict # update from user namespace without overriding special namedtuple attributes for key in ns: - if not hasattr(nm_tpl, key): + if key in _prohibited: + raise AttributeError("Cannot overwrite NamedTuple attribute " + key) + elif key not in _special and key not in nm_tpl._fields: setattr(nm_tpl, key, ns[key]) return nm_tpl |