python协程

#！/usr/bin/env python
# -*- coding:utf-8 -*-
import gevent
from gevent import monkey;monkey.patch_all()
import requests

def f(url):
    print('GET:%s'% url)
    res = requests.get(url)
    data= res.text
    print(url,len(data))

gevent.joinall(
    [gevent.spawn(f,'http://www.baidu.com'),
     gevent.spawn(f, 'http://www.qq.com'),
    gevent.spawn(f,'http://www.58.com'),
    gevent.spawn(f,'http://www.python.org'),
     ]
)

'''
def foo():
    print('run foo.....')
    gevent.sleep(2)
    print('switch to foo.....')

def bar():
    print('run bar.....')
    gevent.sleep(3)
    print('switch to bar.....')

gevent.joinall([
    gevent.spawn(foo),
    gevent.spawn(bar)])
'''

 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。