协程

import gevent
节省了多线程之间相互切换的时间消耗，优于多线程，常和多进程结合使用

eg：

import gevent
from  gevent import monkey

monkey.patch_socket()#补丁
def work(num):
    for i in range(num):
        time.sleep(0.5)

    print('今天吃了{}个苹果'.format(num))
lis = [3, 4] * 4
def gev():
    gev_lis = [gevent.spawn(work, i) for i in lis]
    gevent.joinall(gev_lis)
gev()