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__) #?