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__) #?