携程，

》》》》》携程greenlet模块

from greenlet import greenlet
def test1():
    print(15)
    gr1.switch()
    print(16)
    gr1.switch()
def test2():
    print(25)
    gr2.switch()
    print(26)
    gr2.switch()
gr2 = greenlet(test1) #启动一个携程
gr1 = greenlet(test2)
# gr2.switch()
gr2.switch()

 1，注意开关的顺序所造成的不同结果

》》》》》yield

import time
def consumer(name):#消费者
    print('start eat baozi')
    while True:
        new_baozi = yield#阻塞有包子就吃没有就等待
        print("[%s] is eatting %s baozi"%(name,new_baozi))
        
def producer():#生产者
    r = con1.__next__()
    r = con2.__next__()
    n = 0
    while n < 5:
        n += 1
        con1.send(n)
        con2.send(n)
        time.sleep(1)
        print("生产%s包子 "%n)
        
if __name__ =='__main__':
    con1 = consumer("c1")
    con2 = consumer("c2")
    p = producer()

1,生产者消费者模型，yield阻塞等待

》》》》》爬虫

from gevent import monkey;
import gevent
from urllib.request import urlopen
import time

def f(url):
    print("get : %s" % url)
    resp = urlopen(url)
    data = resp.read()
    print("%s bytes recv from %s"%(len(data) , url))

time_start = time.time()
gevent.joinall([
    gevent.spawn(f,'https://www.python.org/'),
    gevent.spawn(f, 'https://www.yahoo.com/'),
    gevent.spawn(f, 'https://github.com/'),
])

print("同步cost",time.time() - time_start)

__author__ = "Alex Li"

from gevent import monkey;

# monkey.patch_all()
import gevent
from  urllib.request import urlopen
import time

def f(url):
    print('GET: %s' % url)
    resp = urlopen(url)
    data = resp.read()
    print('%d bytes received from %s.' % (len(data), url))

urls = [ 'https://www.python.org/',
         'https://www.yahoo.com/',
         'https://github.com/'
         ]


async_time_start = time.time()
gevent.joinall([
    gevent.spawn(f, 'https://www.python.org/'),
    gevent.spawn(f, 'https://www.yahoo.com/'),
    gevent.spawn(f, 'https://github.com/'),
])
print("异步cost",time.time()-async_time_start )