Python typing.ClassVar() Examples

def test_last_args(self):
        T = TypeVar('T')
        S = TypeVar('S')
        self.assertEqual(get_last_args(int), ())
        self.assertEqual(get_last_args(Union), ())
        if WITH_CLASSVAR:
            self.assertEqual(get_last_args(ClassVar[int]), (int,))
        self.assertEqual(get_last_args(Union[T, int]), (T, int))
        self.assertEqual(get_last_args(Union[str, int]), (str, int))
        self.assertEqual(get_last_args(Tuple[T, int]), (T, int))
        self.assertEqual(get_last_args(Tuple[str, int]), (str, int))
        self.assertEqual(get_last_args(Generic[T]), (T, ))
        if GENERIC_TUPLE_PARAMETRIZABLE:
            tp = Iterable[Tuple[T, S]][int, T]
            self.assertEqual(get_last_args(tp), (int, T))
        if LEGACY_TYPING:
            self.assertEqual(get_last_args(Callable[[T, S], int]), (T, S))
            self.assertEqual(get_last_args(Callable[[], int]), ())
        else:
            self.assertEqual(get_last_args(Callable[[T, S], int]), (T, S, int))
            self.assertEqual(get_last_args(Callable[[], int]), (int,)) 

def test_other_params(self):
        C = make_dataclass('C',
                           [('x', int),
                            ('y', ClassVar[int], 10),
                            ('z', ClassVar[int], field(default=20)),
                            ],
                           init=False)
        # Make sure we have a repr, but no init.
        self.assertNotIn('__init__', vars(C))
        self.assertIn('__repr__', vars(C))

        # Make sure random other params don't work.
        with self.assertRaisesRegex(TypeError, 'unexpected keyword argument'):
            C = make_dataclass('C',
                               [],
                               xxinit=False) 

def test_isnt_classvar(self):
        for typestr in ('CV',
                        't.ClassVar',
                        't.ClassVar[int]',
                        'typing..ClassVar[int]',
                        'Classvar',
                        'Classvar[int]',
                        'typing.ClassVarx[int]',
                        'typong.ClassVar[int]',
                        'dataclasses.ClassVar[int]',
                        'typingxClassVar[str]',
                        ):
            with self.subTest(typestr=typestr):
                @dataclass
                class C:
                    x: typestr

                # x is not a ClassVar, so C() takes one arg.
                self.assertEqual(C(10).x, 10) 

def test_isnt_classvar(self):
        for typestr in ('CV',
                        't.ClassVar',
                        't.ClassVar[int]',
                        'typing..ClassVar[int]',
                        'Classvar',
                        'Classvar[int]',
                        'typing.ClassVarx[int]',
                        'typong.ClassVar[int]',
                        'dataclasses.ClassVar[int]',
                        'typingxClassVar[str]',
                        ):
            with self.subTest(typestr=typestr):
                @dataclass
                class C:
                    x: typestr

                # x is not a ClassVar, so C() takes one arg.
                self.assertEqual(C(10).x, 10) 

def test_other_params(self):
        C = make_dataclass('C',
                           [('x', int),
                            ('y', ClassVar[int], 10),
                            ('z', ClassVar[int], field(default=20)),
                            ],
                           init=False)
        # Make sure we have a repr, but no init.
        self.assertNotIn('__init__', vars(C))
        self.assertIn('__repr__', vars(C))

        # Make sure random other params don't work.
        with self.assertRaisesRegex(TypeError, 'unexpected keyword argument'):
            C = make_dataclass('C',
                               [],
                               xxinit=False) 

def test_pickle(self):
        global C  # pickle wants to reference the class by name
        T = TypeVar('T')

        class B(Generic[T]):
            pass

        class C(B[int]):
            pass

        c = C()
        c.foo = 42
        c.bar = 'abc'
        for proto in range(pickle.HIGHEST_PROTOCOL + 1):
            z = pickle.dumps(c, proto)
            x = pickle.loads(z)
            self.assertEqual(x.foo, 42)
            self.assertEqual(x.bar, 'abc')
            self.assertEqual(x.__dict__, {'foo': 42, 'bar': 'abc'})
        simples = [Any, Union, Tuple, Callable, ClassVar, List, typing.Iterable]
        for s in simples:
            for proto in range(pickle.HIGHEST_PROTOCOL + 1):
                z = pickle.dumps(s, proto)
                x = pickle.loads(z)
                self.assertEqual(s, x) 

def __subclasscheck__(self, cls):
            raise TypeError("ClassVar cannot be used with issubclass().") 

def get_by_postfix(model: ClassVar, filename: str, postfix: str) -> str:
        """
        :param model:
        :param filename:
        :param postfix:
        :return str:
        """
        return getattr(model, _ModelUtils.add_postfix(filename, postfix)) 

def get_attr_from_model(wrapped: ClassVar, new_cols: List, file_names: List, db: Any) -> Any:
        """
        Adds values to new_cols & file_names so as not to
        change the size of the dict at runtime
        :return None:
        """
        for attr, value in wrapped.__dict__.items():
            if isinstance(value, Column):
                new_cols.append(_ModelUtils.columns_dict(attr, db))
                file_names.append(str(attr))
        return new_cols, file_names 

def remove_unused_cols(wrapped: ClassVar,  filenames: Tuple[str]) -> None:
        """
        Removes the original named attributes
        (this could be a good place to store
         metadata in a dict for example...)
        :return:
        """
        for col_name in filenames:
            delattr(wrapped, col_name) 

def set_columns(wrapped: ClassVar, new_cols: Tuple[Dict[str, Any]]) -> None:
        """
        Sets related file data to a SqlAlchemy Model
        :return:
        """
        for col_dict in new_cols:
            for k, v in col_dict.items():
                setattr(wrapped, k, v) 

def __eq__(self, other):
            if not isinstance(other, ClassVar):
                return NotImplemented
            if self.__type__ is not None:
                return self.__type__ == other.__type__
            return self is other 

def test_classvar():
    @pydantic.dataclasses.dataclass
    class TestClassVar:
        klassvar: ClassVar = "I'm a Class variable"
        x: int

    tcv = TestClassVar(2)
    assert tcv.klassvar == "I'm a Class variable" 

def __instancecheck__(self, obj):
            raise TypeError("ClassVar cannot be used with isinstance().") 

def is_class_var(t):
    if PY_36:
        return (
            is_special_typing_primitive(t) and
            type(t).__name__ == '_ClassVar'
        )
    if PY_37 or PY_38:
        return get_type_origin(t) is typing.ClassVar
    else:
        raise NotImplementedError 

def cls_branch(
        self, branch_name: str = None,
    ):
        def decorator(cls: typing.ClassVar):
            self.names[branch_name or cls.__name__] = (
                cls,
                ImmutableBranchData(branch_name),
            )
            return cls

        return decorator 

def construct(self, *args, **kwargs) -> typing.ClassVar:
        """ Construct new object """
        pass 

def test_classvar():
    T = TypeVar('T')

    class Result(GenericModel, Generic[T]):
        data: T
        other: ClassVar[int] = 1

    assert Result.other == 1
    assert Result[int].other == 1
    assert Result[int](data=1).other == 1
    assert 'other' not in Result.__fields__ 

def test_no_isinstance(self):
        with self.assertRaises(TypeError):
            isinstance(1, ClassVar[int])
        with self.assertRaises(TypeError):
            issubclass(int, ClassVar) 

def test_class_var():
    class MyModel(BaseModel):
        a: ClassVar
        b: ClassVar[int] = 1
        c: int = 2

    assert list(MyModel.__fields__.keys()) == ['c'] 

def test_class_var(self):
        # Make sure ClassVars are ignored in __init__, __repr__, etc.
        @dataclass
        class C:
            x: int
            y: int = 10
            z: ClassVar[int] = 1000
            w: ClassVar[int] = 2000
            t: ClassVar[int] = 3000
            s: ClassVar      = 4000

        c = C(5)
        self.assertEqual(repr(c), 'TestCase.test_class_var.<locals>.C(x=5, y=10)')
        self.assertEqual(len(fields(C)), 2)                 # We have 2 fields.
        self.assertEqual(len(C.__annotations__), 6)         # And 4 ClassVars.
        self.assertEqual(c.z, 1000)
        self.assertEqual(c.w, 2000)
        self.assertEqual(c.t, 3000)
        self.assertEqual(c.s, 4000)
        C.z += 1
        self.assertEqual(c.z, 1001)
        c = C(20)
        self.assertEqual((c.x, c.y), (20, 10))
        self.assertEqual(c.z, 1001)
        self.assertEqual(c.w, 2000)
        self.assertEqual(c.t, 3000)
        self.assertEqual(c.s, 4000) 

def test_class_var_no_default(self):
        # If a ClassVar has no default value, it should not be set on the class.
        @dataclass
        class C:
            x: ClassVar[int]

        self.assertNotIn('x', C.__dict__) 

def test_class_var_default_factory(self):
        # It makes no sense for a ClassVar to have a default factory. When
        #  would it be called? Call it yourself, since it's class-wide.
        with self.assertRaisesRegex(TypeError,
                                    'cannot have a default factory'):
            @dataclass
            class C:
                x: ClassVar[int] = field(default_factory=int)

            self.assertNotIn('x', C.__dict__) 

def test_class_var_with_default(self):
        # If a ClassVar has a default value, it should be set on the class.
        @dataclass
        class C:
            x: ClassVar[int] = 10
        self.assertEqual(C.x, 10)

        @dataclass
        class C:
            x: ClassVar[int] = field(default=10)
        self.assertEqual(C.x, 10) 

def test_classvar_default_factory(self):
        # It's an error for a ClassVar to have a factory function.
        with self.assertRaisesRegex(TypeError,
                                    'cannot have a default factory'):
            @dataclass
            class C:
                x: ClassVar[int] = field(default_factory=int) 

def test_classvar(self):
        # Some expressions recognized as ClassVar really aren't.  But
        #  if you're using string annotations, it's not an exact
        #  science.
        # These tests assume that both "import typing" and "from
        # typing import *" have been run in this file.
        for typestr in ('ClassVar[int]',
                        'ClassVar [int]'
                        ' ClassVar [int]',
                        'ClassVar',
                        ' ClassVar ',
                        'typing.ClassVar[int]',
                        'typing.ClassVar[str]',
                        ' typing.ClassVar[str]',
                        'typing .ClassVar[str]',
                        'typing. ClassVar[str]',
                        'typing.ClassVar [str]',
                        'typing.ClassVar [ str]',

                        # Not syntactically valid, but these will
                        #  be treated as ClassVars.
                        'typing.ClassVar.[int]',
                        'typing.ClassVar+',
                        ):
            with self.subTest(typestr=typestr):
                @dataclass
                class C:
                    x: typestr

                # x is a ClassVar, so C() takes no args.
                C()

                # And it won't appear in the class's dict because it doesn't
                # have a default.
                self.assertNotIn('x', C.__dict__) 

def test_class_var(self):
        C = make_dataclass('C',
                           [('x', int),
                            ('y', ClassVar[int], 10),
                            ('z', ClassVar[int], field(default=20)),
                            ])
        c = C(1)
        self.assertEqual(vars(c), {'x': 1})
        self.assertEqual(len(fields(c)), 1)
        self.assertEqual(C.y, 10)
        self.assertEqual(C.z, 20) 

def __init__(self, extensions: ClassVar):
        self.extensions = extensions 

def test_classvar(self):
        T = TypeVar('T')
        samples = [ClassVar, ClassVar[int], ClassVar[List[T]]]
        nonsamples = [int, 42, Iterable, List[int], type, T]
        self.sample_test(is_classvar, samples, nonsamples) 

def test_class_var(self):
        # Make sure ClassVars are ignored in __init__, __repr__, etc.
        @dataclass
        class C:
            x: int
            y: int = 10
            z: ClassVar[int] = 1000
            w: ClassVar[int] = 2000
            t: ClassVar[int] = 3000
            s: ClassVar      = 4000

        c = C(5)
        self.assertEqual(repr(c), 'TestCase.test_class_var.<locals>.C(x=5, y=10)')
        self.assertEqual(len(fields(C)), 2)                 # We have 2 fields.
        self.assertEqual(len(C.__annotations__), 6)         # And 4 ClassVars.
        self.assertEqual(c.z, 1000)
        self.assertEqual(c.w, 2000)
        self.assertEqual(c.t, 3000)
        self.assertEqual(c.s, 4000)
        C.z += 1
        self.assertEqual(c.z, 1001)
        c = C(20)
        self.assertEqual((c.x, c.y), (20, 10))
        self.assertEqual(c.z, 1001)
        self.assertEqual(c.w, 2000)
        self.assertEqual(c.t, 3000)
        self.assertEqual(c.s, 4000)