python协程

 1 #！/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 import gevent
 4 from gevent import monkey;monkey.patch_all()
 5 import requests
 6 
 7 def f(url):
 8     print('GET:%s'% url)
 9     res = requests.get(url)
10     data= res.text
11     print(url,len(data))
12 
13 gevent.joinall(
14     [gevent.spawn(f,'http://www.baidu.com'),
15      gevent.spawn(f, 'http://www.qq.com'),
16     gevent.spawn(f,'http://www.58.com'),
17     gevent.spawn(f,'http://www.python.org'),
18      ]
19 )
20 
21 '''
22 def foo():
23     print('run foo.....')
24     gevent.sleep(2)
25     print('switch to foo.....')
26 
27 def bar():
28     print('run bar.....')
29     gevent.sleep(3)
30     print('switch to bar.....')
31 
32 gevent.joinall([
33     gevent.spawn(foo),
34     gevent.spawn(bar)])
35 '''

生产者消费者模型

#！/usr/bin/env python
# -*- coding:utf-8 -*-
def consumer():
    last = ''
    while True:
        receival = yield last
        if receival is not None:
            print('Consume %s' % receival)
            last = receival


def producer(gen, n):
    gen.__next__()
    x = 0
    while x < n:
        x += 1
        print('Produce %s' % x)
        last = gen.send(x)

    gen.close()

gen = consumer()
producer(gen, 5)

消费者consumer()函数是一个生成器函数，每次执行到yield时即挂起，并返回上一次的结果给生产者。生产者producer()接收到生成器的返回，并生成一个新的值，通过send()方法发送给消费者。