import unittest from test.support import cpython_only try: import _testcapi except ImportError: _testcapi = None import struct import collections import itertools import gc import contextlib class BadStr(str): def __eq__(self, other): return True def __hash__(self): # Guaranteed different hash return str.__hash__(self) ^ 3 class FunctionCalls(unittest.TestCase): def test_kwargs_order(self): # bpo-34320: **kwargs should preserve order of passed OrderedDict od = collections.OrderedDict([('a', 1), ('b', 2)]) od.move_to_end('a') expected = list(od.items()) def fn(**kw): return kw res = fn(**od) self.assertIsInstance(res, dict) self.assertEqual(list(res.items()), expected) @cpython_only class CFunctionCallsErrorMessages(unittest.TestCase): def test_varargs0(self): msg = r"__contains__\(\) takes exactly one argument \(0 given\)" self.assertRaisesRegex(TypeError, msg, {}.__contains__) def test_varargs2(self): msg = r"__contains__\(\) takes exactly one argument \(2 given\)" self.assertRaisesRegex(TypeError, msg, {}.__contains__, 0, 1) def test_varargs3(self): msg = r"^from_bytes\(\) takes exactly 2 positional arguments \(3 given\)" self.assertRaisesRegex(TypeError, msg, int.from_bytes, b'a', 'little', False) def test_varargs1min(self): msg = r"get expected at least 1 argument, got 0" self.assertRaisesRegex(TypeError, msg, {}.get) msg = r"expected 1 argument, got 0" self.assertRaisesRegex(TypeError, msg, {}.__delattr__) def test_varargs2min(self): msg = r"getattr expected at least 2 arguments, got 0" self.assertRaisesRegex(TypeError, msg, getattr) def test_varargs1max(self): msg = r"input expected at most 1 argument, got 2" self.assertRaisesRegex(TypeError, msg, input, 1, 2) def test_varargs2max(self): msg = r"get expected at most 2 arguments, got 3" self.assertRaisesRegex(TypeError, msg, {}.get, 1, 2, 3) def test_varargs1_kw(self): msg = r"__contains__\(\) takes no keyword arguments" self.assertRaisesRegex(TypeError, msg, {}.__contains__, x=2) def test_varargs2_kw(self): msg = r"__contains__\(\) takes no keyword arguments" self.assertRaisesRegex(TypeError, msg, {}.__contains__, x=2, y=2) def test_varargs3_kw(self): msg = r"bool\(\) takes no keyword arguments" self.assertRaisesRegex(TypeError, msg, bool, x=2) def test_varargs4_kw(self): msg = r"^list[.]index\(\) takes no keyword arguments$" self.assertRaisesRegex(TypeError, msg, [].index, x=2) def test_varargs5_kw(self): msg = r"^hasattr\(\) takes no keyword arguments$" self.assertRaisesRegex(TypeError, msg, hasattr, x=2) def test_varargs6_kw(self): msg = r"^getattr\(\) takes no keyword arguments$" self.assertRaisesRegex(TypeError, msg, getattr, x=2) def test_varargs7_kw(self): msg = r"^next\(\) takes no keyword arguments$" self.assertRaisesRegex(TypeError, msg, next, x=2) def test_varargs8_kw(self): msg = r"^_struct[.]pack\(\) takes no keyword arguments$" self.assertRaisesRegex(TypeError, msg, struct.pack, x=2) def test_varargs9_kw(self): msg = r"^_struct[.]pack_into\(\) takes no keyword arguments$" self.assertRaisesRegex(TypeError, msg, struct.pack_into, x=2) def test_varargs10_kw(self): msg = r"^deque[.]index\(\) takes no keyword arguments$" self.assertRaisesRegex(TypeError, msg, collections.deque().index, x=2) def test_varargs11_kw(self): msg = r"^Struct[.]pack\(\) takes no keyword arguments$" self.assertRaisesRegex(TypeError, msg, struct.Struct.pack, struct.Struct(""), x=2) def test_varargs12_kw(self): msg = r"^staticmethod\(\) takes no keyword arguments$" self.assertRaisesRegex(TypeError, msg, staticmethod, func=id) def test_varargs13_kw(self): msg = r"^classmethod\(\) takes no keyword arguments$" self.assertRaisesRegex(TypeError, msg, classmethod, func=id) def test_varargs14_kw(self): msg = r"^product\(\) takes at most 1 keyword argument \(2 given\)$" self.assertRaisesRegex(TypeError, msg, itertools.product, 0, repeat=1, foo=2) def test_varargs15_kw(self): msg = r"^ImportError\(\) takes at most 2 keyword arguments \(3 given\)$" self.assertRaisesRegex(TypeError, msg, ImportError, 0, name=1, path=2, foo=3) def test_varargs16_kw(self): msg = r"^min\(\) takes at most 2 keyword arguments \(3 given\)$" self.assertRaisesRegex(TypeError, msg, min, 0, default=1, key=2, foo=3) def test_varargs17_kw(self): msg = r"^print\(\) takes at most 4 keyword arguments \(5 given\)$" self.assertRaisesRegex(TypeError, msg, print, 0, sep=1, end=2, file=3, flush=4, foo=5) def test_varargs18_kw(self): # _PyArg_UnpackKeywordsWithVararg() msg = r"invalid keyword argument for print\(\)$" with self.assertRaisesRegex(TypeError, msg): print(0, 1, **{BadStr('foo'): ','}) def test_varargs19_kw(self): # _PyArg_UnpackKeywords() msg = r"invalid keyword argument for round\(\)$" with self.assertRaisesRegex(TypeError, msg): round(1.75, **{BadStr('foo'): 1}) def test_oldargs0_1(self): msg = r"keys\(\) takes no arguments \(1 given\)" self.assertRaisesRegex(TypeError, msg, {}.keys, 0) def test_oldargs0_2(self): msg = r"keys\(\) takes no arguments \(2 given\)" self.assertRaisesRegex(TypeError, msg, {}.keys, 0, 1) def test_oldargs0_1_kw(self): msg = r"keys\(\) takes no keyword arguments" self.assertRaisesRegex(TypeError, msg, {}.keys, x=2) def test_oldargs0_2_kw(self): msg = r"keys\(\) takes no keyword arguments" self.assertRaisesRegex(TypeError, msg, {}.keys, x=2, y=2) def test_oldargs1_0(self): msg = r"count\(\) takes exactly one argument \(0 given\)" self.assertRaisesRegex(TypeError, msg, [].count) def test_oldargs1_2(self): msg = r"count\(\) takes exactly one argument \(2 given\)" self.assertRaisesRegex(TypeError, msg, [].count, 1, 2) def test_oldargs1_0_kw(self): msg = r"count\(\) takes no keyword arguments" self.assertRaisesRegex(TypeError, msg, [].count, x=2) def test_oldargs1_1_kw(self): msg = r"count\(\) takes no keyword arguments" self.assertRaisesRegex(TypeError, msg, [].count, {}, x=2) def test_oldargs1_2_kw(self): msg = r"count\(\) takes no keyword arguments" self.assertRaisesRegex(TypeError, msg, [].count, x=2, y=2) class TestCallingConventions(unittest.TestCase): """Test calling using various C calling conventions (METH_*) from Python Subclasses test several kinds of functions (module-level, methods, class methods static methods) using these attributes: obj: the object that contains tested functions (as attributes) expected_self: expected "self" argument to the C function The base class tests module-level functions. """ def setUp(self): self.obj = self.expected_self = _testcapi def test_varargs(self): self.assertEqual( self.obj.meth_varargs(1, 2, 3), (self.expected_self, (1, 2, 3)), ) def test_varargs_ext(self): self.assertEqual( self.obj.meth_varargs(*(1, 2, 3)), (self.expected_self, (1, 2, 3)), ) def test_varargs_error_kw(self): msg = r"meth_varargs\(\) takes no keyword arguments" self.assertRaisesRegex( TypeError, msg, lambda: self.obj.meth_varargs(k=1), ) def test_varargs_keywords(self): self.assertEqual( self.obj.meth_varargs_keywords(1, 2, a=3, b=4), (self.expected_self, (1, 2), {'a': 3, 'b': 4}) ) def test_varargs_keywords_ext(self): self.assertEqual( self.obj.meth_varargs_keywords(*[1, 2], **{'a': 3, 'b': 4}), (self.expected_self, (1, 2), {'a': 3, 'b': 4}) ) def test_o(self): self.assertEqual(self.obj.meth_o(1), (self.expected_self, 1)) def test_o_ext(self): self.assertEqual(self.obj.meth_o(*[1]), (self.expected_self, 1)) def test_o_error_no_arg(self): msg = r"meth_o\(\) takes exactly one argument \(0 given\)" self.assertRaisesRegex(TypeError, msg, self.obj.meth_o) def test_o_error_two_args(self): msg = r"meth_o\(\) takes exactly one argument \(2 given\)" self.assertRaisesRegex( TypeError, msg, lambda: self.obj.meth_o(1, 2), ) def test_o_error_ext(self): msg = r"meth_o\(\) takes exactly one argument \(3 given\)" self.assertRaisesRegex( TypeError, msg, lambda: self.obj.meth_o(*(1, 2, 3)), ) def test_o_error_kw(self): msg = r"meth_o\(\) takes no keyword arguments" self.assertRaisesRegex( TypeError, msg, lambda: self.obj.meth_o(k=1), ) def test_o_error_arg_kw(self): msg = r"meth_o\(\) takes no keyword arguments" self.assertRaisesRegex( TypeError, msg, lambda: self.obj.meth_o(k=1), ) def test_noargs(self): self.assertEqual(self.obj.meth_noargs(), self.expected_self) def test_noargs_ext(self): self.assertEqual(self.obj.meth_noargs(*[]), self.expected_self) def test_noargs_error_arg(self): msg = r"meth_noargs\(\) takes no arguments \(1 given\)" self.assertRaisesRegex( TypeError, msg, lambda: self.obj.meth_noargs(1), ) def test_noargs_error_arg2(self): msg = r"meth_noargs\(\) takes no arguments \(2 given\)" self.assertRaisesRegex( TypeError, msg, lambda: self.obj.meth_noargs(1, 2), ) def test_noargs_error_ext(self): msg = r"meth_noargs\(\) takes no arguments \(3 given\)" self.assertRaisesRegex( TypeError, msg, lambda: self.obj.meth_noargs(*(1, 2, 3)), ) def test_noargs_error_kw(self): msg = r"meth_noargs\(\) takes no keyword arguments" self.assertRaisesRegex( TypeError, msg, lambda: self.obj.meth_noargs(k=1), ) def test_fastcall(self): self.assertEqual( self.obj.meth_fastcall(1, 2, 3), (self.expected_self, (1, 2, 3)), ) def test_fastcall_ext(self): self.assertEqual( self.obj.meth_fastcall(*(1, 2, 3)), (self.expected_self, (1, 2, 3)), ) def test_fastcall_error_kw(self): msg = r"meth_fastcall\(\) takes no keyword arguments" self.assertRaisesRegex( TypeError, msg, lambda: self.obj.meth_fastcall(k=1), ) def test_fastcall_keywords(self): self.assertEqual( self.obj.meth_fastcall_keywords(1, 2, a=3, b=4), (self.expected_self, (1, 2), {'a': 3, 'b': 4}) ) def test_fastcall_keywords_ext(self): self.assertEqual( self.obj.meth_fastcall_keywords(*(1, 2), **{'a': 3, 'b': 4}), (self.expected_self, (1, 2), {'a': 3, 'b': 4}) ) class TestCallingConventionsInstance(TestCallingConventions): """Test calling instance methods using various calling conventions""" def setUp(self): self.obj = self.expected_self = _testcapi.MethInstance() class TestCallingConventionsClass(TestCallingConventions): """Test calling class methods using various calling conventions""" def setUp(self): self.obj = self.expected_self = _testcapi.MethClass class TestCallingConventionsClassInstance(TestCallingConventions): """Test calling class methods on instance""" def setUp(self): self.obj = _testcapi.MethClass() self.expected_self = _testcapi.MethClass class TestCallingConventionsStatic(TestCallingConventions): """Test calling static methods using various calling conventions""" def setUp(self): self.obj = _testcapi.MethStatic() self.expected_self = None def pyfunc(arg1, arg2): return [arg1, arg2] def pyfunc_noarg(): return "noarg" class PythonClass: def method(self, arg1, arg2): return [arg1, arg2] def method_noarg(self): return "noarg" @classmethod def class_method(cls): return "classmethod" @staticmethod def static_method(): return "staticmethod" PYTHON_INSTANCE = PythonClass() NULL_OR_EMPTY = object() class FastCallTests(unittest.TestCase): """Test calling using various callables from C """ # Test calls with positional arguments CALLS_POSARGS = [ # (func, args: tuple, result) # Python function with 2 arguments (pyfunc, (1, 2), [1, 2]), # Python function without argument (pyfunc_noarg, (), "noarg"), # Python class methods (PythonClass.class_method, (), "classmethod"), (PythonClass.static_method, (), "staticmethod"), # Python instance methods (PYTHON_INSTANCE.method, (1, 2), [1, 2]), (PYTHON_INSTANCE.method_noarg, (), "noarg"), (PYTHON_INSTANCE.class_method, (), "classmethod"), (PYTHON_INSTANCE.static_method, (), "staticmethod"), # C callables are added later ] # Test calls with positional and keyword arguments CALLS_KWARGS = [ # (func, args: tuple, kwargs: dict, result) # Python function with 2 arguments (pyfunc, (1,), {'arg2': 2}, [1, 2]), (pyfunc, (), {'arg1': 1, 'arg2': 2}, [1, 2]), # Python instance methods (PYTHON_INSTANCE.method, (1,), {'arg2': 2}, [1, 2]), (PYTHON_INSTANCE.method, (), {'arg1': 1, 'arg2': 2}, [1, 2]), # C callables are added later ] # Add all the calling conventions and variants of C callables _instance = _testcapi.MethInstance() for obj, expected_self in ( (_testcapi, _testcapi), # module-level function (_instance, _instance), # bound method (_testcapi.MethClass, _testcapi.MethClass), # class method on class (_testcapi.MethClass(), _testcapi.MethClass), # class method on inst. (_testcapi.MethStatic, None), # static method ): CALLS_POSARGS.extend([ (obj.meth_varargs, (1, 2), (expected_self, (1, 2))), (obj.meth_varargs_keywords, (1, 2), (expected_self, (1, 2), NULL_OR_EMPTY)), (obj.meth_fastcall, (1, 2), (expected_self, (1, 2))), (obj.meth_fastcall, (), (expected_self, ())), (obj.meth_fastcall_keywords, (1, 2), (expected_self, (1, 2), NULL_OR_EMPTY)), (obj.meth_fastcall_keywords, (), (expected_self, (), NULL_OR_EMPTY)), (obj.meth_noargs, (), expected_self), (obj.meth_o, (123, ), (expected_self, 123)), ]) CALLS_KWARGS.extend([ (obj.meth_varargs_keywords, (1, 2), {'x': 'y'}, (expected_self, (1, 2), {'x': 'y'})), (obj.meth_varargs_keywords, (), {'x': 'y'}, (expected_self, (), {'x': 'y'})), (obj.meth_varargs_keywords, (1, 2), {}, (expected_self, (1, 2), NULL_OR_EMPTY)), (obj.meth_fastcall_keywords, (1, 2), {'x': 'y'}, (expected_self, (1, 2), {'x': 'y'})), (obj.meth_fastcall_keywords, (), {'x': 'y'}, (expected_self, (), {'x': 'y'})), (obj.meth_fastcall_keywords, (1, 2), {}, (expected_self, (1, 2), NULL_OR_EMPTY)), ]) def check_result(self, result, expected): if isinstance(expected, tuple) and expected[-1] is NULL_OR_EMPTY: if result[-1] in ({}, None): expected = (*expected[:-1], result[-1]) self.assertEqual(result, expected) def test_fastcall(self): # Test _PyObject_FastCall() for func, args, expected in self.CALLS_POSARGS: with self.subTest(func=func, args=args): result = _testcapi.pyobject_fastcall(func, args) self.check_result(result, expected) if not args: # args=NULL, nargs=0 result = _testcapi.pyobject_fastcall(func, None) self.check_result(result, expected) def test_vectorcall_dict(self): # Test PyObject_VectorcallDict() for func, args, expected in self.CALLS_POSARGS: with self.subTest(func=func, args=args): # kwargs=NULL result = _testcapi.pyobject_fastcalldict(func, args, None) self.check_result(result, expected) if not args: # args=NULL, nargs=0, kwargs=NULL result = _testcapi.pyobject_fastcalldict(func, None, None) self.check_result(result, expected) for func, args, kwargs, expected in self.CALLS_KWARGS: with self.subTest(func=func, args=args, kwargs=kwargs): result = _testcapi.pyobject_fastcalldict(func, args, kwargs) self.check_result(result, expected) def test_vectorcall(self): # Test PyObject_Vectorcall() for func, args, expected in self.CALLS_POSARGS: with self.subTest(func=func, args=args): # kwnames=NULL result = _testcapi.pyobject_vectorcall(func, args, None) self.check_result(result, expected) # kwnames=() result = _testcapi.pyobject_vectorcall(func, args, ()) self.check_result(result, expected) if not args: # kwnames=NULL result = _testcapi.pyobject_vectorcall(func, None, None) self.check_result(result, expected) # kwnames=() result = _testcapi.pyobject_vectorcall(func, None, ()) self.check_result(result, expected) for func, args, kwargs, expected in self.CALLS_KWARGS: with self.subTest(func=func, args=args, kwargs=kwargs): kwnames = tuple(kwargs.keys()) args = args + tuple(kwargs.values()) result = _testcapi.pyobject_vectorcall(func, args, kwnames) self.check_result(result, expected) def test_fastcall_clearing_dict(self): # Test bpo-36907: the point of the test is just checking that this # does not crash. class IntWithDict: __slots__ = ["kwargs"] def __init__(self, **kwargs): self.kwargs = kwargs def __index__(self): self.kwargs.clear() gc.collect() return 0 x = IntWithDict(dont_inherit=IntWithDict()) # We test the argument handling of "compile" here, the compilation # itself is not relevant. When we pass flags=x below, x.__index__() is # called, which changes the keywords dict. compile("pass", "", "exec", x, **x.kwargs) Py_TPFLAGS_HAVE_VECTORCALL = 1 << 11 Py_TPFLAGS_METHOD_DESCRIPTOR = 1 << 17 def testfunction(self): """some doc""" return self def testfunction_kw(self, *, kw): """some doc""" return self class TestPEP590(unittest.TestCase): def test_method_descriptor_flag(self): import functools cached = functools.lru_cache(1)(testfunction) self.assertFalse(type(repr).__flags__ & Py_TPFLAGS_METHOD_DESCRIPTOR) self.assertTrue(type(list.append).__flags__ & Py_TPFLAGS_METHOD_DESCRIPTOR) self.assertTrue(type(list.__add__).__flags__ & Py_TPFLAGS_METHOD_DESCRIPTOR) self.assertTrue(type(testfunction).__flags__ & Py_TPFLAGS_METHOD_DESCRIPTOR) self.assertTrue(type(cached).__flags__ & Py_TPFLAGS_METHOD_DESCRIPTOR) self.assertTrue(_testcapi.MethodDescriptorBase.__flags__ & Py_TPFLAGS_METHOD_DESCRIPTOR) self.assertTrue(_testcapi.MethodDescriptorDerived.__flags__ & Py_TPFLAGS_METHOD_DESCRIPTOR) self.assertFalse(_testcapi.MethodDescriptorNopGet.__flags__ & Py_TPFLAGS_METHOD_DESCRIPTOR) # Heap type should not inherit Py_TPFLAGS_METHOD_DESCRIPTOR class MethodDescriptorHeap(_testcapi.MethodDescriptorBase): pass self.assertFalse(MethodDescriptorHeap.__flags__ & Py_TPFLAGS_METHOD_DESCRIPTOR) def test_vectorcall_flag(self): self.assertTrue(_testcapi.MethodDescriptorBase.__flags__ & Py_TPFLAGS_HAVE_VECTORCALL) self.assertTrue(_testcapi.MethodDescriptorDerived.__flags__ & Py_TPFLAGS_HAVE_VECTORCALL) self.assertFalse(_testcapi.MethodDescriptorNopGet.__flags__ & Py_TPFLAGS_HAVE_VECTORCALL) self.assertTrue(_testcapi.MethodDescriptor2.__flags__ & Py_TPFLAGS_HAVE_VECTORCALL) # Heap type should not inherit Py_TPFLAGS_HAVE_VECTORCALL class MethodDescriptorHeap(_testcapi.MethodDescriptorBase): pass self.assertFalse(MethodDescriptorHeap.__flags__ & Py_TPFLAGS_HAVE_VECTORCALL) def test_vectorcall_override(self): # Check that tp_call can correctly override vectorcall. # MethodDescriptorNopGet implements tp_call but it inherits from # MethodDescriptorBase, which implements vectorcall. Since # MethodDescriptorNopGet returns the args tuple when called, we check # additionally that no new tuple is created for this call. args = tuple(range(5)) f = _testcapi.MethodDescriptorNopGet() self.assertIs(f(*args), args) def test_vectorcall(self): # Test a bunch of different ways to call objects: # 1. vectorcall using PyVectorcall_Call() # (only for objects that support vectorcall directly) # 2. normal call # 3. vectorcall using PyObject_Vectorcall() # 4. call as bound method # 5. call using functools.partial # A list of (function, args, kwargs, result) calls to test calls = [(len, (range(42),), {}, 42), (list.append, ([], 0), {}, None), ([].append, (0,), {}, None), (sum, ([36],), {"start":6}, 42), (testfunction, (42,), {}, 42), (testfunction_kw, (42,), {"kw":None}, 42), (_testcapi.MethodDescriptorBase(), (0,), {}, True), (_testcapi.MethodDescriptorDerived(), (0,), {}, True), (_testcapi.MethodDescriptor2(), (0,), {}, False)] from _testcapi import pyobject_vectorcall, pyvectorcall_call from types import MethodType from functools import partial def vectorcall(func, args, kwargs): args = *args, *kwargs.values() kwnames = tuple(kwargs) return pyobject_vectorcall(func, args, kwnames) for (func, args, kwargs, expected) in calls: with self.subTest(str(func)): if not kwargs: self.assertEqual(expected, pyvectorcall_call(func, args)) self.assertEqual(expected, pyvectorcall_call(func, args, kwargs)) # Add derived classes (which do not support vectorcall directly, # but do support all other ways of calling). class MethodDescriptorHeap(_testcapi.MethodDescriptorBase): pass class MethodDescriptorOverridden(_testcapi.MethodDescriptorBase): def __call__(self, n): return 'new' class SuperBase: def __call__(self, *args): return super().__call__(*args) class MethodDescriptorSuper(SuperBase, _testcapi.MethodDescriptorBase): def __call__(self, *args): return super().__call__(*args) calls += [ (dict.update, ({},), {"key":True}, None), ({}.update, ({},), {"key":True}, None), (MethodDescriptorHeap(), (0,), {}, True), (MethodDescriptorOverridden(), (0,), {}, 'new'), (MethodDescriptorSuper(), (0,), {}, True), ] for (func, args, kwargs, expected) in calls: with self.subTest(str(func)): args1 = args[1:] meth = MethodType(func, args[0]) wrapped = partial(func) if not kwargs: self.assertEqual(expected, func(*args)) self.assertEqual(expected, pyobject_vectorcall(func, args, None)) self.assertEqual(expected, meth(*args1)) self.assertEqual(expected, wrapped(*args)) self.assertEqual(expected, func(*args, **kwargs)) self.assertEqual(expected, vectorcall(func, args, kwargs)) self.assertEqual(expected, meth(*args1, **kwargs)) self.assertEqual(expected, wrapped(*args, **kwargs)) class A: def method_two_args(self, x, y): pass @staticmethod def static_no_args(): pass @staticmethod def positional_only(arg, /): pass @cpython_only class TestErrorMessagesUseQualifiedName(unittest.TestCase): @contextlib.contextmanager def check_raises_type_error(self, message): with self.assertRaises(TypeError) as cm: yield self.assertEqual(str(cm.exception), message) def test_missing_arguments(self): msg = "A.method_two_args() missing 1 required positional argument: 'y'" with self.check_raises_type_error(msg): A().method_two_args("x") def test_too_many_positional(self): msg = "A.static_no_args() takes 0 positional arguments but 1 was given" with self.check_raises_type_error(msg): A.static_no_args("oops it's an arg") def test_positional_only_passed_as_keyword(self): msg = "A.positional_only() got some positional-only arguments passed as keyword arguments: 'arg'" with self.check_raises_type_error(msg): A.positional_only(arg="x") def test_unexpected_keyword(self): msg = "A.method_two_args() got an unexpected keyword argument 'bad'" with self.check_raises_type_error(msg): A().method_two_args(bad="x") def test_multiple_values(self): msg = "A.method_two_args() got multiple values for argument 'x'" with self.check_raises_type_error(msg): A().method_two_args("x", "y", x="oops") if __name__ == "__main__": unittest.main()