getter, setter 정리

1.기본

class Test:
    __name = "John"

    def get_name(self):
        return self.__name
    
    def set_name(self, value):
        self.__name = value

if __name__ == "__main__":
    t = Test()
    print(t.get_name())
    t.set_name("David")
    print(t.get_name())

 

2. property 사용

class Test:
    __name = "John"

    def get_name(self):
        return self.__name
    
    def set_name(self, value):
        self.__name = value

    name = property(get_name, set_name)

if __name__ == "__main__":
    t = Test()
    print(t.name)
    t.name = "David"
    print(t.name)

 

3. @property(데코레이터:Decorator) 사용

class Test:
    __name = "John"

    @property
    def name(self):
        return self.__name

    @name.setter
    def name(self, value):
        self.__name = value

if __name__ == "__main__":
    t = Test()
    print(t.name)
    t.name = "David"
    print(t.name)

 

4. 여러 속성에 대해서 동일하게 처리해야할 경우, @property를 사용하면 코드가 지저분해지므로, Descriptor를 하면 코드가 깔끔하게 정리됨.

class T:
    __name = ""

    def __get__(self, instance, owner):
        return getattr(instance, "__name")

    def __set__(self, instance, value):
        setattr(instance, "__name", value)

class Test:
    name = T()

if __name__ == "__main__":
    t = Test()
    t1 = Test()
    t2 = Test()
    t.name = "David"
    t1.age = 40
    t2.address = "Korea"
    print(t.name, t1.age, t2.address)

 

<참고>
https://docs.python.org/3/howto/descriptor.html