Python之面向对象slots与迭代器协议

Python之面向对象slots与迭代器协议

　　slots：

 # class People:

 #     x=1

 #     def __init__(self,name):

 #         self.name=name

 #     def run(self):

 #         pass

 # print(People.__dict__)

 #

 # p=People('alex')

 # print(p.__dict__)

 class People:

     __slots__=['x','y','z']

 p=People()

 print(People.__dict__)

 p.x=1

 p.y=2

 p.z=3

 print(p.x,p.y,p.z)

 # print(p.__dict__)

 p1=People()

 p1.x=10

 p1.y=20

 p1.z=30

 print(p1.x,p1.y,p1.z)

 print(p1.__dict__)

　　item系列：

 #把对象操作属性模拟成字典的格式

 class Foo:

     def __init__(self,name):

         self.name=name

     def __setattr__(self, key, value):

         print('setattr===>')

     def __getitem__(self, item):

         # print('getitem',item)

         return self.__dict__[item]

     def __setitem__(self, key, value):

         print('setitem-----<')

         self.__dict__[key]=value

     def __delitem__(self, key):

         self.__dict__.pop(key)

         # self.__dict__.pop(key)

     # def __delattr__(self, item):

     #     print('del obj.key时,我执行')

     #     self.__dict__.pop(item)

 f=Foo('George')

 f.name='Wang'

 f['name']='George'

 # print(f.name)

 # f.name='George'

 # f['age']=18

 # print(f.__dict__)

 #

 # del f['age'] #del f.age

 # print(f.__dict__)

 # print(f['name'])

　　__next__、__iter__ 实现迭代器协议：

 # from collections import Iterable,Iterator

 # class Foo:

 #     def __init__(self,start):

 #         self.start=start

 #     def __iter__(self):

 #         return self

 #     def __next__(self):

 #         return 'aSB'

 # f=Foo(0)

 # f.__iter__()

 # f.__next__()

 # print(isinstance(f,Iterable))

 # print(isinstance(f,Iterator))

 # print(next(f)) #f.__next__()

 # print(next(f)) #f.__next__()

 # print(next(f)) #f.__next__()

 # for i in f: # res=f.__iter__() #next(res)

 #     print(i)

 # from collections import Iterable,Iterator

 # class Foo:

 #     def __init__(self,start):

 #         self.start=start

 #     def __iter__(self):

 #         return self

 #     def __next__(self):

 #         if self.start > 10:

 #             raise StopIteration

 #         n=self.start

 #         self.start+=1

 #         return n

 # f=Foo(0)

 # print(next(f))

 # print(next(f))

 # print(next(f))

 # print(next(f))

 # print(next(f))

 # print(next(f))

 # print(next(f))

 # print(next(f))

 # print(next(f))

 # print(next(f))

 # print(next(f))

 # print(next(f))

 # for i in f:

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

 # class Range:

 #     '123'

 #     def __init__(self,start,end):

 #         self.start=start

 #         self.end=end

 #     def __iter__(self):

 #         return self

 #     def __next__(self):

 #         if self.start == self.end:

 #             raise StopIteration

 #         n=self.start

 #         self.start+=1

 #         return n

 # for i in Range(0,3):

 #     print(i)

 # print(Range.__doc__)

 class Foo:

     '我是描述信息'

     pass

 class Bar(Foo):

     pass

 print(Bar.__doc__) #该属性无法继承给子类

 b=Bar()

 print(b.__class__)

 print(b.__module__)

 print(Foo.__module__)

 print(Foo.__class__) #?