def foo():print('starting')while True:x=yield None#return 2print('value ：',x)
g=foo()
print(next(g))
print(g.send(2))运行结果：
starting  #运行函数，打印starting后碰到yield停住
None　　　 #next()触发后 yield将None赋值给x，打印None后循环碰到yield停住
value ： 2　　#g.send(2)将2赋值给yield，yield将2赋值给x，继续循环打印出2碰到yield停住
None　　　　  #碰到yield停住并返回None,print的结果就是None

def init(func):def wrapper(*args,**kwargs):g=func(*args,**kwargs)next(g)return greturn wrapper@init #foo=init(foo)
def foo():print('starting')while True:x=yieldprint('value ：',x)
g=foo() #wrapper()
g.send(2)运行结果：
starting
value ：2

# _*_ coding:utf-8 _*_
def init(func):def wrapper(*args,**kwargs):g=func(*args,**kwargs)next(g)return greturn wrapper
@init
def eater(name):print('%s ready to eat'%name)food_list=[]while True:food=yield food_listfood_list.append(food)print('%s start to eat %s'%(name,food))e=eater('alex')
print(e.send('food1'))
print(e.send('food2'))
print(e.send('food3'))运行结果：
alex ready to eat
alex start to eat food1
['food1']
alex start to eat food2
['food1', 'food2']
alex start to eat food3
['food1', 'food2', 'food3']

import os
#装饰器，自动next()
def init(func):def wrapper(*args,**kwargs):g = func(*args,**kwargs)next(g)return greturn wrapper
#j阶段一:递归地找出目录下所有文件的绝对路径，把路径发给阶段二
@init
def search(target):'search file abspath'while True:start_path=yieldg = os.walk(start_path)for par_dir,_,files in g:for file in files:file_path = r'%s\%s' %(par_dir,file)target.send(file_path)
#阶段二:收到文件路径，打开文件获取文件对象，把文件对象发给阶段三
@init
def opener(target):while True:file_path = yieldwith open(file_path,encoding = 'utf-8') as f:target.send((file_path,f))
#阶段三：收到文件对象，for循环读取文件的每一行内容，把每一行内容发给阶段四
@init
def cat(target):while True:file_path,f = yieldfor line in f:res=target.send((file_path,line))if res:break
#阶段四：收到一行内容，判断root是否在这一行中，如果在，则把文件名发给阶段五
@init
def grep(target,pattern):tag=Falsewhile True:filepath,line=yield tagtag=Falseif pattern in line:target.send(filepath)tag=True
#阶段五：收到文件名，打印结果
@init
def printer():while True:filename = yieldprint(filename)
start_path = r'E:\PycharmProjects\qz5\day9'
# search(opener(cat(grep(printer(),'Jack'))),start_path)
g=search(opener(cat(grep(printer(),'Jack'))))
g.send(start_path)