简单介绍协程
1 #!/usr/bin/env python 2 #-*-coding:utf-8 -*- 3 4 ''' 5 协程: 协作式(线程、进程的切换都是抢占式)----------非抢占式 6 协作式不代表没有切换,只是什么时候切换,完全在于我们自己的需求,因此协程的关键点也是什么时候切换。 7 yield(协程) ,yield相当于一个临时的return,下次还可以在进来 8 9 先理解生成器,yield,next,send, 10 回顾一下:有yield的函数是创建生成器,想调用需要.next或者__next__,send是往函数了发东西,函数了卡主的yield接收 11 12 yield属于最底层的协程切换,Python有模块greenlet 13 ''' 14 15 # import time 16 # 17 # def consumer(name): 18 # 19 # print("--->ready to eat baozi...") 20 # while True: 21 # new_baozi = yield 22 # print("[%s] is eating baozi %s" % (name,new_baozi)) 23 # time.sleep(1) 24 # 25 # def producer(): 26 # 27 # r = con.__next__() 28 # r = con2.__next__() # 这里运行了consumer,但是consumer函数会到new_baozi = yield卡住,因为它在等待接收send发送的数据 29 # 30 # n = 0 31 # while 1: 32 # time.sleep(1) 33 # print("\033[32;1m[producer]\033[0m is making baozi %s and %s" %(n,n+1) ) 34 # con.send(n) 35 # con2.send(n+1) 36 # n +=2 37 # 38 # 39 # if __name__ == '__main__': 40 # 41 # con = consumer("c1") 42 # con2 = consumer("c2") # 单单这两行,consumer里面的print是不会打印的,因为它只是产生生成器 43 # producer() 44 45 46 ######################################################################################################################## 47 ######################################################################################################################## 48 49 from greenlet import greenlet 50 51 def test1(): 52 print(12) 53 gr2.switch() 54 print(34) 55 def test2(): 56 print(56) 57 gr1.switch() 58 print(78) 59 gr1.switch() 60 61 gr1 = greenlet(test1) # 用模块greenlet封装函数test1 62 gr2 = greenlet(test2) 63 gr2.switch() # (切换)运行gr2