import math
import json
import msgpack
import pickleclass Shape:"""防止直接调用父类的area方法"""@propertydef area(self):raise NotImplementedError('基类未实现')class Triangle(Shape):"""三角形"""def __init__(self,a,b,c):self.a = aself.b = bself.c = c@propertydef area(self):p = (self.a+self.b+self.c)/2return math.sqrt(p*(p-self.a)*(p-self.b)*(p-self.c))class Rectangle(Shape):"""矩形"""def __init__(self,width,height):self.width = widthself.height = height@propertydef area(self):return self.width * self.heightdef SerializableCircle(cls):""" 1.装饰器为类动态添加dumps方法"""# print(cls)def dumps(self,t='json'):if t == 'json':return json.dumps(self.__dict__)elif t == 'msgpack':return msgpack.packb(self.__dict__)elif t == 'pickle':with open('dump.txt','wb') as f:return pickle.dump(self.__dict__,f)else:raise NotImplementedError('没有实现的序列化')cls.dumps = dumpsreturn cls@SerializableCircle     # Circle=SerializableCircle(Circle)
class Circle(Shape):"""圆形"""def __init__(self,radius):self.radius = radius@propertydef area(self):return (self.radius ** 2) * math.pi# def dumps(self,t='json'):#     if t == 'json':#         return json.dumps(self.__dict__)#     elif t == 'msgpack':#         return msgpack.packb(self.__dict__)#     elif t == 'pickle':#         with open('dump.txt','wb') as f:#             return pickle.dump(self.__dict__,f)#     else:#         raise NotImplementedError('没有实现的序列化')# sc = Circle(4)
# sc.dumps('pickle')class SerializableMixin:"""序列化"""def dumps(self,t='json'):if t == 'json':return json.dumps(self.__dict__)elif t == 'msgpack':return msgpack.packb(self.__dict__)elif t == 'pickle':with open('dump.txt','wb') as f:return pickle.dump(self.__dict__,f)else:raise NotImplementedError('没有实现的序列化')def loads(self,t='json'):passclass SerializableCircleMixin(SerializableMixin,Circle):""" 2.Mixin组合为类动态添加dumps方法"""passshapes = [Triangle(3,4,5), Rectangle(3,4), Circle(4)]
for s in shapes:print('The area of {} = {}'.format(s.__class__.__name__,s.area))#Mixin
scm = SerializableCircleMixin(4)
print(scm.area)
s = scm.dumps('msgpack')
print(s)#装饰器
sc = Circle(4)
s = sc.dumps('json')
print(s)