Source code for blocks.utils.reflection

import logging
import emloop as el

__all__ = ['try_import']


def try_import(class_fqn: str) -> type:
    """
    Try to import and return the specified class. If it fails return an empty class instead.

    .. code-block:: python
        :caption: example usage with **hipipe** dataset

        import blocks as bl

        class OdoCapDataset(bl.utils.try_import('my_module.Dataset'),
                            bl.datasets.RectangleRPNDataset,
                            metaclass=bl.utils.classmaker()):

    :param class_fqn: class fully qualified name
    :return: specified class or an empty class
    """
    module, name = el.utils.parse_fully_qualified_name(class_fqn)
    try:
        class_ = el.utils.get_attribute(module, name)
        return class_

    except (ModuleNotFoundError, AttributeError):
        logging.warning('Could not import class `%s` from module `%s`. Creating `ObjectProxy` class instead.',
                        name, module)

        class EmptyClass:
            pass

        return EmptyClass