register_cls.py

_registry_path = Path(__file__).parent / 'registry.json'
if _registry_path.exists():
    with _registry_path.open(encoding='utf-8') as f:
        _REGISTRY = json.load(f)
else:
    _REGISTRY = {}

def short_name(cls: type) -> str:
    """Returns just a class name (without package and module specification)."""
    return cls.__name__.split('.')[-1]

def register(name: str = None) -> type:
    """
    Register classes that could be initialized from JSON configuration file.
    If name is not passed, the class name is converted to snake-case.
    """
    def decorate(model_cls: type, reg_name: str = None) -> type:
        model_name = reg_name or short_name(model_cls)
        global _REGISTRY
        cls_name = model_cls.__module__ + ':' + model_cls.__name__
        if model_name in _REGISTRY and _REGISTRY[model_name] != cls_name:
            logger.warning('Registry name "{}" has been already registered and will be overwritten.'.format(model_name))
        _REGISTRY[model_name] = cls_name
        return model_cls

    return lambda model_cls_name: decorate(model_cls_name, name)