From e612c28513b406779d187e5f816445c7d40d292b Mon Sep 17 00:00:00 2001 From: Mariatta Date: Wed, 3 May 2017 09:38:01 -0700 Subject: [3.6] bpo-28556: Routine updates to typing (GH-1366) (#1416) - Add NoReturn type - Use WrapperDescriptorType (original PR by Jim Fasarakis-Hilliard) - Minor bug-fixes (cherry picked from commit f06e0218ef6007667f5d61184b85a81a0466d3ae) --- Lib/test/test_typing.py | 51 ++++++++++++++++++++++++++++++++++++++++++++----- Lib/typing.py | 35 +++++++++++++++++++++++++++++---- Misc/NEWS | 4 ++++ 3 files changed, 81 insertions(+), 9 deletions(-) diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py index f0070ec..b3cabda 100644 --- a/Lib/test/test_typing.py +++ b/Lib/test/test_typing.py @@ -6,7 +6,7 @@ import sys from unittest import TestCase, main, skipUnless, SkipTest from copy import copy, deepcopy -from typing import Any +from typing import Any, NoReturn from typing import TypeVar, AnyStr from typing import T, KT, VT # Not in __all__. from typing import Union, Optional @@ -102,10 +102,6 @@ class AnyTests(BaseTestCase): with self.assertRaises(TypeError): type(Any)() - def test_cannot_subscript(self): - with self.assertRaises(TypeError): - Any[int] - def test_any_works_with_alias(self): # These expressions must simply not fail. typing.Match[Any] @@ -113,6 +109,40 @@ class AnyTests(BaseTestCase): typing.IO[Any] +class NoReturnTests(BaseTestCase): + + def test_noreturn_instance_type_error(self): + with self.assertRaises(TypeError): + isinstance(42, NoReturn) + + def test_noreturn_subclass_type_error(self): + with self.assertRaises(TypeError): + issubclass(Employee, NoReturn) + with self.assertRaises(TypeError): + issubclass(NoReturn, Employee) + + def test_repr(self): + self.assertEqual(repr(NoReturn), 'typing.NoReturn') + + def test_not_generic(self): + with self.assertRaises(TypeError): + NoReturn[int] + + def test_cannot_subclass(self): + with self.assertRaises(TypeError): + class A(NoReturn): + pass + with self.assertRaises(TypeError): + class A(type(NoReturn)): + pass + + def test_cannot_instantiate(self): + with self.assertRaises(TypeError): + NoReturn() + with self.assertRaises(TypeError): + type(NoReturn)() + + class TypeVarTests(BaseTestCase): def test_basic_plain(self): @@ -2273,6 +2303,14 @@ class XMethBad(NamedTuple): return 'no chance for this' """) + with self.assertRaises(AttributeError): + exec(""" +class XMethBad2(NamedTuple): + x: int + def _source(self): + return 'no chance for this as well' +""") + @skipUnless(PY36, 'Python 3.6 required') def test_namedtuple_keyword_usage(self): LocalEmployee = NamedTuple("LocalEmployee", name=str, age=int) @@ -2420,6 +2458,9 @@ class AllTests(BaseTestCase): self.assertNotIn('sys', a) # Check that Text is defined. self.assertIn('Text', a) + # Check previously missing classes. + self.assertIn('SupportsBytes', a) + self.assertIn('SupportsComplex', a) if __name__ == '__main__': diff --git a/Lib/typing.py b/Lib/typing.py index 9a0f490..645bc6f 100644 --- a/Lib/typing.py +++ b/Lib/typing.py @@ -11,9 +11,9 @@ try: except ImportError: import collections as collections_abc # Fallback for PY3.2. try: - from types import SlotWrapperType, MethodWrapperType, MethodDescriptorType + from types import WrapperDescriptorType, MethodWrapperType, MethodDescriptorType except ImportError: - SlotWrapperType = type(object.__init__) + WrapperDescriptorType = type(object.__init__) MethodWrapperType = type(object().__str__) MethodDescriptorType = type(str.join) @@ -63,6 +63,8 @@ __all__ = [ # Structural checks, a.k.a. protocols. 'Reversible', 'SupportsAbs', + 'SupportsBytes', + 'SupportsComplex', 'SupportsFloat', 'SupportsInt', 'SupportsRound', @@ -420,6 +422,31 @@ class _Any(_FinalTypingBase, _root=True): Any = _Any(_root=True) +class _NoReturn(_FinalTypingBase, _root=True): + """Special type indicating functions that never return. + Example:: + + from typing import NoReturn + + def stop() -> NoReturn: + raise Exception('no way') + + This type is invalid in other positions, e.g., ``List[NoReturn]`` + will fail in static type checkers. + """ + + __slots__ = () + + def __instancecheck__(self, obj): + raise TypeError("NoReturn cannot be used with isinstance().") + + def __subclasscheck__(self, cls): + raise TypeError("NoReturn cannot be used with issubclass().") + + +NoReturn = _NoReturn(_root=True) + + class TypeVar(_TypingBase, _root=True): """Type variable. @@ -1450,7 +1477,7 @@ def _get_defaults(func): _allowed_types = (types.FunctionType, types.BuiltinFunctionType, types.MethodType, types.ModuleType, - SlotWrapperType, MethodWrapperType, MethodDescriptorType) + WrapperDescriptorType, MethodWrapperType, MethodDescriptorType) def get_type_hints(obj, globalns=None, localns=None): @@ -2051,7 +2078,7 @@ _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') + '_make', '_replace', '_asdict', '_source') _special = ('__module__', '__name__', '__qualname__', '__annotations__') diff --git a/Misc/NEWS b/Misc/NEWS index 3b61543..1c9026e 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -36,6 +36,10 @@ Core and Builtins Library ------- +- bpo-28556: Various updates to typing module: add typing.NoReturn type, use + WrapperDescriptorType, minor bug-fixes. Original PRs by + Jim Fasarakis-Hilliard and Ivan Levkivskyi. + - bpo-30205: Fix getsockname() for unbound AF_UNIX sockets on Linux. - bpo-30070: Fixed leaks and crashes in errors handling in the parser module. -- cgit v0.12