Python学习第十九课——类的装饰器

类的装饰器

# def deco(func):

#     print('==========')

#     return func

#

# # @deco       #test=deco(test)

# # def test():

# #     print('test函数运行')

# # test()

#

# @deco #Foo=deco(Foo)

# class Foo:

#     pass

def deco(obj):

    print('==========',obj)

    obj.x=1

    obj.y=2

    obj.z=3

    return obj

# @deco #Foo=deco(Foo)

# class Foo:

#     pass

#

# print(Foo.__dict__)

#一切皆对象

# # @deco #test=deco(test)

# def test():

#     print('test函数')

# test.x=1

# test.y=1

# print(test.__dict__)

类的装饰器加强版

def Typed(**kwargs):

    def deco(obj):

        for key,val in kwargs.items():

            # obj.key=val

            setattr(obj,key,val)

        return obj

    return deco

@Typed(x=1,y=2,z=3)   #1.Typed(x=1,y=2,z=3) --->deco   2.@deco---->Foo=deco(Foo)

class Foo:

    pass

print(Foo.__dict__)

# @Typed(name='egon')  #@deco   ---->Bar=deco(Bar)

# class Bar:

#     pass

# print(Bar.name)

类的装饰器的应用

class Typed:

    def __init__(self,key,expected_type):

        self.key=key

        self.expected_type=expected_type

    def __get__(self, instance, owner):

        print('get方法')

        # print('instance参数【%s】' %instance)

        # print('owner参数【%s】' %owner)

        return instance.__dict__[self.key]

    def __set__(self, instance, value):

        print('set方法')

        # print('instance参数【%s】' % instance)

        # print('value参数【%s】' % value)

        # print('====>',self)

        if not isinstance(value,self.expected_type):

            # print('你传入的类型不是字符串，错误')

            # return

            raise TypeError('%s 传入的类型不是%s' %(self.key,self.expected_type))

        instance.__dict__[self.key]=value

    def __delete__(self, instance):

        print('delete方法')

        # print('instance参数【%s】' % instance)

        instance.__dict__.pop(self.key)

def deco(**kwargs): #kwargs={'name':str,'age':int}

    def wrapper(obj): #obj=People

        for key,val in kwargs.items():#(('name',str),('age',int))

            setattr(obj,key,Typed(key,val))

            # setattr(People,'name',Typed('name',str)) #People.name=Typed('name',str)

        return obj

    return wrapper

@deco(name=str,age=int)  #@wrapper ===>People=wrapper(People)

class People:

    name='alex'

    # name=Typed('name',str)

    # age=Typed('age',int)

    def __init__(self,name,age,salary,gender,heigth):

        self.name=name

        self.age=age

        self.salary=salary

# p1=People('213',13.3,13.3,'x','y')

print(People.__dict__)