自定制方法

class property2:
    def __init__(self, func):
        print('执行property2')
        self.func = func

    def __get__(self, instance, owner):
        print('执行get')
        setattr(instance, self.func.__name__, self.func(instance))
        return self.func(instance)

    def __set__(self, instance, value):  # 加上set方法就变成数据描述符，优先级变高。导致每次执行
        print('set')


class Room:
    def __init__(self, name, width, length):
        self.name = name
        self.width = width
        self.length = length

    @property2  # area = property2(area)
    def area(self):
        return self.width * self.length


r1 = Room('cesuo', 100, 20)
print(r1.area)  # 如果是非数据描述符那就是先从实例属性中去找。
print(r1.area)  # 如果是数据描述符那就从先从类属性中找，然后从数据描述符中找。
print(r1.area)
print(r1.area)
print(r1.__dict__)
输出：
执行property2
执行get
set
2000
执行get
set
2000
执行get
set
2000
执行get
set
2000
{'name': 'cesuo', 'width': 100, 'length': 20}

非数据描述符就比实例属性优先级更低，从而不用每次都去执行描述符。而是先从实例属性字典去中找

下面的为自定义类方法：

class ClassMethod:
    def __init__(self, func):
        self.func = func

    def __get__(self, instance, owner):
        def wrapper(*args,**kwargs):
            print('123456789')
            return self.func(owner,*args,**kwargs)

        return wrapper


class Foo:
    def __init__(self, name, age, gender):
        self.name = name
        self.age = age
        self.gender = gender

    @ClassMethod
    def test(cls, name,age):
        print('ok%s%s' % (name,age))


Foo.test('nihao',132)
输出：
123456789
oknihao132

下面的为自定义静态方法：

class Method:
    def __init__(self, func):
        print('+++++++++++')
        self.func = func

    def __get__(self, instance, owner):
        def wrapper(*args, **kwargs):
            return self.func(*args, **kwargs)

        return wrapper


class Foo:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    @Method
    def test(a, b, c):
        print('ok%s%s%s' % (a, b, c))


Foo.test(1,2,3)
f1 = Foo('alex',123)
f1.test(4,5,6)
输出：
+++++++++++
ok123
ok456