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day27-python之迭代器协议

2019年08月18日 | 移动技术网IT编程 | 我要评论

撑死,太阳的后裔11,傲妃本色

1.item系列方法

# class foo:
#     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):
#         print('delitem')
#         self.__dict__.pop(key)
#
class foo:
    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):
        print('delitem')
        self.__dict__.pop(key)

f1 = foo()
print(f1.__dict__)
f1.name = 'egon'
# f1['name'] = 'egon'
f1['age'] = 18
# print(f1.__dict__)


# del f1.name
# print(f1.age)

# del f1['name']
# print(f1.__dict__)
print(f1['age'])
raise  stopasynciteration
# f1=foo()
# print(f1.__dict__)
# # f1.name='egon'  #---->setattr-------->f1.__dict__['name']='egon'
# f1['name']='egon'#--->setitem--------->f1.__dict__['name']='egon'
# f1['age']=18
#
# print('===>',f1.__dict__)
#
# # del f1.name
# # print(f1.__dict__)
# #
# # print(f1.age)
# del f1['name']
# print(f1.__dict__)
#
# print(f1['age'])
# raise s

2.slots属性

class foo:
    __slots__ = ['name','age']

f1 = foo()
f1.name = 'egon'
print(f1.name)


# class foo:
#     __slots__=['name','age']  #{'name':none,'age':none}
    # __slots__='name' #{'name':none,'age':none}

# f1=foo()
# f1.name='egon'
# print(f1.name)

# f1.age=18  #--->setattr----->f1.__dict__['age']=18


f1.age = 18
# print(f1.__dict__)
print(foo.__slots__)
print(f1.__slots__)

f1.name = 'egon'
f1.age = 17
print(f1.name)
print(f1.age)
# print(f1.__dict__)
# print(foo.__slots__)
# print(f1.__slots__)
# f1.name='egon'
# f1.age=17
# print(f1.name)
# print(f1.age)
# f1.gender='male'


# f1.gender = 'male'

f2 = foo()
print(f2.__slots__)
f2.name = 'alex'
f2.age = 18
print(f2.name)
print(f2.age)

# f2=foo()
# print(f2.__slots__)
# f2.name='alex'
# f2.age=18
# print(f2.name)
# print(f2.age)

3.内置方法

class foo:
    x = 1
    def __init__(self,y):
        self.y = y

    def __getattr__(self, item):
        print('------> from getattr:你找的属性不存在')

    def __setattr__(self, key, value):
        print('-----> from setattr')
        self.__dict__[key] = value

    def __delattr__(self, item):
        print('-----> from delattr')
        self.__dict__.pop(item)


f1 = foo(10)

# class foo:
#     x=1
#     def __init__(self,y):
#         self.y=y
#
#     def __getattr__(self, item):
#         print('----> from getattr:你找的属性不存在')
#
#
#     def __setattr__(self, key, value):
#         print('----> from setattr')
#         # self.key=value #这就无限递归了,你好好想想
#         # self.__dict__[key]=value #应该使用它
#
#     def __delattr__(self, item):
#         print('----> from delattr')
#         # del self.item #无限递归了
#         self.__dict__.pop(item)
#
#
# f1=foo(10)
# f1.x

4.描述符

# class foo:
#     def __get__(self, instance, owner):
#         print('===>get方法')
#     def __set__(self, instance, value):
#         print('===>set方法',instance,value)
#         instance.__dict__['x']=value #b1.__dict__
#     def __delete__(self, instance):
#         print('===>delete方法')


class foo:
    def __get__(self, instance, owner):
        print('===>get方法')

    def __set__(self, instance, value):
        print('===>set方法',instance,value)
        instance.__dict__['x'] = value
    def __delete__(self, instance):
        print('===>delete方法')
class bar:
    x = foo()
    def __init__(self,n):
        self.x = n
b1 = bar(10)
print(b1.__dict__)
b1.x = 11111111111
print(b1.__dict__)

# class bar:
#     x=foo() #在何地？
#     def __init__(self,n):
#         self.x=n #b1.x=10
# b1=bar(10)
# print(b1.__dict__)
# b1.x=11111111111111111
# print(b1.__dict__)
#
b1.y = 111111111111111111111111
print(b1.__dict__)
print(bar.__dict__)

# b1.y=11111111111111111111111111111111111111
# print(b1.__dict__)
# print(bar.__dict__)

b1 = bar()
b1.x = 1
# del  b1.x
print(b1.x)
#在何时？
# b1=bar()
# b1.x
#
# b1.x=1
#
# del b1.x

# print(b1.x)
#
# b1.x=1
# print(b1.__dict__)
#
# del b1.x

5.描述符优先级

# class foo:
#     def  __get__(self, instance, owner):
#         print('===>get方法')
#
#     def __set__(self, instance, value):
#         print('===>set方法',instance,value)
#
#     def __delete__(self, instance):
#         print('===>delete方法')



# class foo:
#     def __get__(self, instance, owner):
#         print('===>get方法')
#     def __set__(self, instance, value):
#         print('===>set方法',instance,value)
#         # instance.__dict__['x']=value #b1.__dict__
#     def __delete__(self, instance):
#         print('===>delete方法')
#
#



# class bar:
#     x=foo() #在何地？

# print(bar.x)


# bar.x=1
# print(bar.__dict__)
# print(bar.x)




# print(bar.__dict__)
# b1=bar()
# b1.x   #get
# b1.x=1 # set
# del b1.x # delete




# b1=bar()
# bar.x=111111111111111111111111111111111111111
# b1.x
#
# del bar.x
# b1.x

class foo:
    def __get__(self, instance, owner):
        print('===>get方法')

    def __delete__(self, instance):
        print('===>delete方法')



class bar:
    x = foo()
    def __getattr__(self, item):
        print('-------->')

b1 = bar()
# b1.x = 1
print(b1.__dict__)
# class foo:
#     def __get__(self, instance, owner):
#         print('===>get方法')
#
#
#     # def __delete__(self, instance):
#     #     print('===>delete方法')
#
#
# class bar:
#     x=foo() #在何地？
#     def  __getattr__(self, item):
#         print('----->')
#
# b1=bar()
# b1.x=1
# print(b1.__dict__)
# b1.xxxxxxxxxxxxxxxxxxxxxxx

6.改变对象的字符串显示

# l=list('hello')
#
# print(l)
# file=open('test.txt','w')
# print(file)



# class foo:
#     def __init__(self,name,age):
#         self.name=name
#         self.age=age
#     def __str__(self):
#         return '名字是%s 年龄是%s' %(self.name,self.age)
#
# f1=foo('egon',18)
# print(f1) #str(f1)--->f1.__str__()
#
# x=str(f1)
# print(x)
#
# y=f1.__str__()
# print(y)

class foo:
    def __init__(self,name,age):
        self.name = name
        self.age = age

    def __str__(self):
        return  '折是str'

    def __repr__(self):
        return  '名字是%s 年龄是%s' %(self.name,self.age)

f1 = foo('as',12)
f1.__repr__()

# class foo:
#     def __init__(self,name,age):
#         self.name=name
#         self.age=age
#     # def __str__(self):
#     #     return '折是str'
#     def __repr__(self):
#         return '名字是%s 年龄是%s' %(self.name,self.age)
#
# f1=foo('egon',19)
# #repr(f1)---->f1.__repr__()
# print(f1) #str（f1）---》f1.__str__()------>f1.__repr__()

7.析构方法

# class foo:
#     def __init__(self,name):
#         self.name=name
#     def __del__(self):
#         print('我执行啦')
#
# f1=foo('alex')
#
# # del f1    #删除实例会触发__del__
# del f1.name #删除实例的属性不会触发__del__
# print('--------------------->')
#
# #程序运行完毕会自动回收内存，触发__del__

class foo:
    def __init__(self,name):
        self.name = name

    def __del__(self):
        print('我执行啦')

f1 = foo('andy')
# del f1.name

8.自定义格式化方法format

# x='{0}{0}{0}'.format('dog')
#
# print(x)


# class date:
#     def __init__(self,year,mon,day):
#         self.year=year
#         self.mon=mon
#         self.day=day
# d1=date(2016,12,26)
#
# x='{0.year}{0.mon}{0.day}'.format(d1)
# y='{0.year}:{0.mon}:{0.day}'.format(d1)
# z='{0.mon}-{0.day}-{0.year}'.format(d1)
# print(x)
# print(y)
# print(z)

# x='{0.year}{0.mon}{0.day}'.format(d1)
# y='{0.year}:{0.mon}:{0.day}'
# z='{0.mon}-{0.day}-{0.year}'

# format_dic={
#     'ymd':'{0.year}{0.mon}{0.day}',
#     'm-d-y':'{0.mon}-{0.day}-{0.year}',
#     'y:m:d':'{0.year}:{0.mon}:{0.day}'
# }
format_dic = {
    'ymd':'{0.year}{0.mon}{0.day}',
    'm-d-y':'{0.mon}-{0.day}-{0.year}',
    'y:m:d':'{0.year}:{0.mon}:{0.day}'
}
class date:
    def  __init__(self,year,mon,day):
        self.year = year
        self.mon = mon
        self.day = day

    def __format__(self, format_spec):
        print('我执行啦')
        print('--->',format_spec)
        if not format_spec or format_spec not in format_dic:
            format_spec = 'ymd'
        fm = format_dic[format_spec]
        return  fm.format(self)

d1 = date(2016,12,13)
print(format(d1,'ymd'))
print(format(d1,'y:m:d'))
print(format(d1,'m-d-y'))
print(format(d1,'m-d:y'))
# class date:
#     def __init__(self,year,mon,day):
#         self.year=year
#         self.mon=mon
#         self.day=day
#     def __format__(self, format_spec):
#         print('我执行啦')
#         print('--->',format_spec)
#         if not format_spec or format_spec not in format_dic:
#             format_spec='ymd'
#         fm=format_dic[format_spec]
#         return fm.format(self)
# d1=date(2016,12,26)
# # format(d1) #d1.__format__()
# # print(format(d1))
# print(format(d1,'ymd'))
# print(format(d1,'y:m:d'))
# print(format(d1,'m-d-y'))
# print(format(d1,'m-d:y'))
# print('===========>',format(d1,'asdfasdfsadfasdfasdfasdfasdfasdfasdfasdfasdfasdfasd'))

print('=============>',format(d1,'assddd'))

9.迭代器协议

# class foo:
#     def __init__(self,n):
#         self.n=n
#     def __iter__(self):
#         return self
#
#     def __next__(self):
#         if self.n == 13:
#             raise stopiteration('终止了')
#         self.n+=1
#         return self.n

class foo:
    def __init__(self,n):
        self.n = n
    def __iter__(self):
        return  self

    def __next__(self):
        if self.n == 13:
            raise stopiteration('终止了')

        self.n+=1
        return self.n
f1 = foo(10)
print(f1.__next__())
print(f1.__next__())

# l=list('hello')
# for i in l:
#     print(i)
# f1=foo(10)
# # print(f1.__next__())
# # print(f1.__next__())
# # print(f1.__next__())
# # print(f1.__next__())
#
# for i in f1:  # obj=iter(f1)------------>f1.__iter__()
#      print(i)  #obj.__next_()

for i in f1:
    print(i)

10.迭代器协议实现斐波那契数列

# class fib:
#     def __init__(self):
#         self._a=1
#         self._b=1
#
#     def __iter__(self):
#         return self
#     def __next__(self):
#         if self._a > 100:
#             raise stopiteration('终止了')
#         self._a,self._b=self._b,self._a + self._b
#         return self._a
class fib:
    def __init__(self):
        self._a = 1
        self._b = 1

    def __iter__(self):
        return  self

    def __next__(self):
        if self._a > 100:
            raise  stopiteration('终止了')

        self._a,self._b=self._b,self._a+self._b
        return self._a

f1 = fib()

print(next(f1))
print(next(f1))
print(next(f1))
print(next(f1))
print(next(f1))
print(next(f1))
# f1=fib()
# print(next(f1))
# print(next(f1))
# print(next(f1))
# print(next(f1))
# print(next(f1))
# print('==================================')
# for i in f1:
#     print(i)

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day27-python之迭代器协议

2019年08月18日 | 移动技术网IT编程 | 我要评论

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