协程函数应用

1.套模板

def init(func):
    def wrapper(*args,**kwargs):
        res=func(*args,**kwargs)
        next(res)
        return res
    return wrapper

def init(func):
    def wrapper(*args,**kwargs):
        res=func(*args,**kwargs)
        next(res)
        return res
    return wrapper

@init   #eater=init(eater)
def eater(name):
    print('%s start to eat' % name)
    food_list=[]
    while True:
        food = yield food_list
        print('%s eat %s' %(name,food))
        food_list.append(food)
e = eater('zhejiangF4')  #wrapper('zhejiangF4')

#e.send('123')
print(e.send('123'))
print(e.send('123'))
print(e.send('123'))


zhejiangF4 start to eat
zhejiangF4 eat 123
['123']
zhejiangF4 eat 123
['123', '123']
zhejiangF4 eat 123
['123', '123', '123']

　　

2.作业1

'''
文件名：a.txt，文件内容如下：
apple 10 3
tesla 100000 1
mac 3000 2
lenovo 30000 3
chicken 10 3
 实现功能：cat a.txt|grep apple
    要求1：实现迭代器函数cat
    要求2：定义迭代器函数grep
    要求3：模拟管道的功能，将cat的处理结果作为grep的输入
    # cat a.txt | grep apple
# 定义迭代器cat
# 定义迭代器grep
# 模拟管道功能, 将cat的处理结果作为grep的输入
'''
def cat(file):
    with open(file) as f:
        for line in f:
            yield line.strip()

def grep(keywords,lines):
    for line in lines:
        if keywords in line:
            yield line
g1 = cat('b.txt')
g2 = grep('apple',g1)
for i in g2:
    print(i)

3.作业2

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

# 生成器的应用, 将下面的函数改为协程函数, 用send来发送url
# def get(url):
#     def index():
#         return urlopen(url).read()
#     return index



from urllib.request import  urlopen
def get():
    while True:　　　　　　 #while不断做这个事。做一个死循环.  (如果没有while根据next传值send传值做几次)
        url=yield         #初始化过了，从暂停位置开始走，把send里面的值传给它yield，把yield的值再给url，在往下执行res，再打印
        res=urlopen(url).read()
        print(res)

g=get()
next(g)         #初始化一下，让函数停在那个位置
g.send('http://www.python.org')


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