Type Safe Metric (Don't look at this... sandbox)

type-safe-metric.py

from types import MethodType


class TypeSafeAttribute(object):
    def _type_of(self, attr):
        if not self._has_attr(attr):
            raise ValueError(f'No attribute defined as annotation: {attr}')
        return self.__annotations__[attr]

    def _has_attr(self, attr):
        return attr in self.__annotations__
        
    def __setattr__(self, attr, value):
        if self._has_attr(attr) and not isinstance(value, self._type_of(attr)):
            raise ValueError(f'Value not of type {self._type_of(attr)}: {value}')
        super().__setattr__(attr, value)
        
def typesafe(clazz):
    clazz._type_of = TypeSafeAttribute._type_of
    clazz._has_attr = MethodType(TypeSafeAttribute._has_attr, clazz)
    clazz.__setattr__ = MethodType(TypeSafeAttribute.__setattr__, clazz) 
    return clazz
    
class Metric():
    pass


@typesafe
class DuplexYield(Metric):
    duplex_bases: int = 0

        
d = DuplexYield()

#DuplexYield().duplex_bases = '2'
DuplexYield().hii = 2