property test

class Something:
    @property
    def radius(self):
        return self.__radius

    @radius.setter
    def radius2(self, radius):
        self.__radius = radius


s = Something()
s.radius2 = 4
print(s.radius2)  # 4
print(s.radius)  # 4
s.radius = 7  # AttributeError: can't set attribute