How to use from_parametrized_dtype method in pandera

Best Python code snippet using pandera_python

engine.py

Source:engine.py

...71            raise ValueError(72                f"Subclasses of {base_names} cannot be registered"73                f" with {cls.__name__}."74            )75    def _register_from_parametrized_dtype(76        cls,77        pandera_dtype_cls: Type[DataType],78    ) -> None:79        method = pandera_dtype_cls.__dict__["from_parametrized_dtype"]80        if not isinstance(method, classmethod):81            raise ValueError(82                f"{pandera_dtype_cls.__name__}.from_parametrized_dtype "83                + "must be a classmethod."84            )85        func = method.__func__86        annotations = get_type_hints(func).values()87        dtype = next(iter(annotations))  # get 1st annotation88        # parse typing.Union89        dtypes = typing_inspect.get_args(dtype) or [dtype]90        def _method(*args, **kwargs):91            return func(pandera_dtype_cls, *args, **kwargs)92        for source_dtype in dtypes:93            cls._check_source_dtype(source_dtype)94            cls._registry[cls].dispatch.register(source_dtype, _method)95    def _register_equivalents(96        cls, pandera_dtype_cls: Type[DataType], *source_dtypes: Any97    ) -> None:98        pandera_dtype = pandera_dtype_cls()  # type: ignore99        for source_dtype in source_dtypes:100            cls._check_source_dtype(source_dtype)101            cls._registry[cls].equivalents[source_dtype] = pandera_dtype102    def register_dtype(103        cls: _EngineType,104        pandera_dtype_cls: Type[_DataType] = None,105        *,106        equivalents: Optional[List[Any]] = None,107    ) -> Callable:108        """Register a Pandera :class:`~pandera.dtypes.DataType` with the engine,109        as class decorator.110        :param pandera_dtype: The DataType to register.111        :param equivalents: Equivalent scalar data type classes or112            non-parametrized data type instances.113        .. note::114            The classmethod ``from_parametrized_dtype`` will also be115            registered. See :ref:`here<dtypes>` for more usage details.116        :example:117        >>> import pandera as pa118        >>>119        >>> class MyDataType(pa.DataType):120        ...     pass121        >>>122        >>> class MyEngine(123        ...     metaclass=pa.engines.engine.Engine,124        ...     base_pandera_dtypes=MyDataType,125        ... ):126        ...     pass127        >>>128        >>> @MyEngine.register_dtype(equivalents=[bool])129        ... class MyBool(MyDataType):130        ...     pass131        """132        def _wrapper(pandera_dtype_cls: Type[_DataType]) -> Type[_DataType]:133            if not inspect.isclass(pandera_dtype_cls):134                raise ValueError(135                    f"{cls.__name__}.register_dtype can only decorate a class,"136                    f" got {pandera_dtype_cls}"137                )138            if equivalents:139                cls._register_equivalents(pandera_dtype_cls, *equivalents)140            if "from_parametrized_dtype" in pandera_dtype_cls.__dict__:141                cls._register_from_parametrized_dtype(pandera_dtype_cls)142            cls._registered_dtypes.add(pandera_dtype_cls)143            return pandera_dtype_cls144        if pandera_dtype_cls:145            return _wrapper(pandera_dtype_cls)146        return _wrapper147    def dtype(cls: _EngineType, data_type: Any) -> _DataType:148        """Convert input into a Pandera :class:`DataType` object."""149        if isinstance(data_type, cls._base_pandera_dtypes):150            return data_type151        if inspect.isclass(data_type) and issubclass(152            data_type, cls._base_pandera_dtypes153        ):154            try:155                return data_type()...

test_engine.py

Source:test_engine.py

...34    with pytest.raises(35        TypeError, match="Data type 'foo' not understood by FakeEngine"36    ):37        engine.dtype("foo")38def test_register_from_parametrized_dtype(engine: Engine):39    """Test that a dtype with from_parametrized_dtype can be registered."""40    @engine.register_dtype41    class _Dtype(BaseDataType):42        @classmethod43        def from_parametrized_dtype(cls, x: int):44            return x45    assert engine.dtype(42) == 4246    with pytest.raises(47        TypeError, match="Data type 'foo' not understood by FakeEngine"48    ):49        engine.dtype("foo")50def test_register_from_parametrized_dtype_union(engine: Engine):51    """Test that a dtype with from_parametrized_dtype and Union annotation52    can be registered.53    """54    @engine.register_dtype55    class _Dtype(BaseDataType):56        @classmethod57        def from_parametrized_dtype(cls, x: Union[int, str]):58            return x59    assert engine.dtype(42) == 4260def test_register_notclassmethod_from_parametrized_dtype(engine: Engine):61    """Test that a dtype with invalid from_parametrized_dtype62    cannot be registered.63    """64    with pytest.raises(65        ValueError,66        match="_InvalidDtype.from_parametrized_dtype must be a classmethod.",67    ):68        @engine.register_dtype69        class _InvalidDtype(BaseDataType):70            def from_parametrized_dtype(  # pylint:disable=no-self-argument,no-self-use71                cls, x: int72            ):73                return x74def test_register_dtype_complete(engine: Engine, equivalents: List[Any]):75    """Test that a dtype with equivalents and from_parametrized_dtype76    can be registered.77    """78    @engine.register_dtype(equivalents=equivalents)79    class _Dtype(BaseDataType):80        @classmethod81        def from_parametrized_dtype(cls, x: Union[int, str]):82            return x83    assert engine.dtype(42) == 4284    assert engine.dtype("foo") == "foo"85    for equivalent in equivalents:86        assert engine.dtype(equivalent) == _Dtype()87    with pytest.raises(88        TypeError,89        match="Data type '<class 'str'>' not understood by FakeEngine",90    ):91        engine.dtype(str)92def test_register_dtype_overwrite(engine: Engine):93    """Test that register_dtype overwrites existing registrations."""94    @engine.register_dtype(equivalents=["foo"])95    class _DtypeA(BaseDataType):96        @classmethod97        def from_parametrized_dtype(cls, x: Union[int, str]):98            return _DtypeA()99    assert engine.dtype("foo") == _DtypeA()100    assert engine.dtype("bar") == _DtypeA()101    assert engine.dtype(42) == _DtypeA()102    @engine.register_dtype(equivalents=["foo"])103    class _DtypeB(BaseDataType):104        @classmethod105        def from_parametrized_dtype(cls, x: int):106            return _DtypeB()107    assert engine.dtype("foo") == _DtypeB()108    assert engine.dtype("bar") == _DtypeA()109    assert engine.dtype(42) == _DtypeB()110def test_register_base_pandera_dtypes():111    """Test that base datatype cannot be registered."""112    class FakeEngine(  # pylint:disable=too-few-public-methods113        metaclass=Engine, base_pandera_dtypes=(BaseDataType, BaseDataType)114    ):115        pass116    with pytest.raises(117        ValueError,118        match=re.escape(119            "Subclasses of ['tests.core.test_engine.BaseDataType', "...

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