Typehints-based deserializer

serializer.py

def _create_config_hierarchy(config_cls: Type[TConfig], config_data: Mapping) -> TConfig:
    sig = signature(config_cls)

    cls_data_attributes = getmembers(config_cls, lambda a: isinstance(a, GenericDescriptor))
    if len(cls_data_attributes) != len(sig.parameters):
        raise TypeError(
            'Type {type_name} has invalid __init__.\n'
            'Init parameters count should equal to data descriptors count.\n'
            'Init parameters: [{init_params}], data descriptors: [{data_descriptors}]'.format(
                type_name=config_cls,
                init_params=', '.join(sig.parameters.keys()),
                data_descriptors=', '.join(attr_name for attr_name, _ in cls_data_attributes),
            )
        )

    config_cls_kwargs: MutableMapping = OrderedDict()
    for kwarg_name, kwarg in sig.parameters.items():
        if kwarg_name == 'self':
            continue

        kwarg_type = kwarg.annotation

        if kwarg_type in (bool, float, int, str, list, tuple) or issubclass(kwarg_type, Enum):
            config_cls_kwargs[kwarg_name] = kwarg_type(config_data[kwarg_name])
        elif kwarg_type in (datetime, date):
            if isinstance(config_data[kwarg_name], kwarg_type):
                # Some parsers will parse dates to objects, not strings
                config_cls_kwargs[kwarg_name] = config_data[kwarg_name]
            else:
                if (
                    (isinstance(config_data[kwarg_name], date) and kwarg_type is datetime) or
                    (isinstance(config_data[kwarg_name], datetime) and kwarg_type is date)
                ):
                    raise TypeError(
                        'Invalid kwarg type while constructing {target_type}. '
                        'Expected {expected_type}, got {got_type}'.format(
                        target_type=config_cls,
                        expected_type=kwarg_type,
                        got_type=type(config_data[kwarg_name])
                    ))
                else:
                    raise NotImplementedError('Dates parsing is not supported')
        elif isinstance(kwarg_type, GenericMeta) and isinstance(config_data[kwarg_name], (list, tuple)):
            # Iterables and Mappings have annotation of type GenericMeta
            # In this case we use actual data type to construct config kwarg
            # Used for kwargs of type List[T], Mapping[KK, KV], etc
            actual_data_type = type(config_data[kwarg_name])
            config_cls_kwargs[kwarg_name] = actual_data_type(config_data[kwarg_name])
        else:
            config_cls_kwargs[kwarg_name] = _create_config_hierarchy(kwarg_type, config_data[kwarg_name])

    return config_cls(**config_cls_kwargs)  # type: ignore