class InstState:
    def __get__(self, instance, owner):
        print('InstState get')
        return instance._X * 10

    def __set__(self, instance, value):
        print('InstState set')
        instance._X = value


class CalcAttrs:
    X = InstState()
    Y = 3

    def __init__(self):
        self._X = 2
        self.Z = 4


obj = CalcAttrs()
print(obj.X, obj.Y, obj.Z)

obj.X = 5
CalcAttrs.Y = 6
obj.Z = 7
print(obj.X, obj.Y, obj.Z)

obj2 = CalcAttrs()
print(obj.X, obj.Y, obj.Z)
