def wrapper(f):    #装饰器函数，f是被装饰的函数

     def inner(*args,**kwargs):

         '''在被装饰函数之前要做的事'''

         print("AAAA")

         ret = f(*args,**kwargs)    #被装饰的函数

         '''在被装饰函数之后要做的事'''

         print("BBBB")

         return ret

     return inner

 @wrapper         #语法糖 @装饰器函数名

 def func(a,b):     #被装饰的函数

     time.sleep(0.01)

     print('大家好',a,b)

     return '新年好'

 func(2,5)

# 迭代器

l = [1, 2, 3]

# for i in l:

#     i:

print(dir([]))  # 列表拥有的方法

"""

['__add__', '__class__', '__contains__', '__delattr__',

 '__delitem__', '__dir__', '__doc__', '__eq__', '__format__',

'__ge__', '__getattribute__', '__getitem__', '__gt__',

'__hash__', '__iadd__', '__imul__', '__init__',

'__init_subclass__', '__iter__', '__le__', '__len__', '__lt__',

'__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__',

'__repr__', '__reversed__', '__rmul__', '__setattr__',

'__setitem__', '__sizeof__', '__str__', '__subclasshook__',

'append', 'clear', 'copy', 'count', 'extend', 'index',

'insert', 'pop', 'remove', 'reverse', 'sort']

"""

# 双下划线的是双下方法

print([1].__add__([2]))  # -->[1, 2]

print([1] + [2])  # -->[1, 2]

ret = set(dir([])) & set(dir({})) & set(dir('')) & set(dir(range(10)))

print(ret)  # iterable  __iter__

# 判断

print('__iter__' in dir([].__iter__()))  # True

print('__next__' in dir([].__iter__()))  # True

from collections import Iterable  # Iterable:可迭代对象

from collections import Iterator  # Iterator迭代器

print(isinstance([], Iterator))  # False  列表不是一个迭代器

print(isinstance([], Iterable))  # True   列表是可迭代的

a = [1, 2, 3, 4]

for b in a.__iter__():

    print(b)

# 打印结果1,2,3,4

def generator():

    print(1)

    return 'a'

ret = generator()

print(ret)     # 结果：1   a

# 生成器函数(含有yield关键字)

def generator1():

    print(1)

    yield 'a'

ret = generator1()

print(ret)   # 结果： <generator object generator1 at 0x0000016AFEFDCF68>

ret.__next__()   # 结果:1

ret.__iter__()

 # 计算移动平均值(1)

 def averager():

     total = 0.0

     count = 0

     average = None

     while True:

         term = yield average

         total += term

         count += 1

         average = total / count

 g_avg = averager()

 next(g_avg)

 print(g_avg.send(10))

 print(g_avg.send(30))

 print(g_avg.send(5))

 # 结果：10.0，20.0，15.0

 # 计算移动平均值(2)_预激协程的装饰器

 def init(func):  # 在调用被装饰生成器函数的时候首先用next激活生成器

     def inner(*args, **kwargs):

         g = func(*args, **kwargs)

         next(g)

         return g

     return inner

 @init

 def averager():

     total = 0.0

     count = 0

     average = None

     while True:

         term = yield average

         total += term

         count += 1

         average = total / count

 g_avg = averager()

 # next(g_avg)   在装饰器中执行了next方法

 print(g_avg.send(10))

 print(g_avg.send(30))

 print(g_avg.send(5))

 # 打印结果10.0，20.0，15.0