在高延迟IO中使用协程的例子

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1. gevent + socket 扫描端口：

#encoding=utf-8
#author: walker
#date: 2014-07-16
#function: 使用协程(异步)方式扫描1000个端口
 
import gevent.monkey
gevent.monkey.patch_socket()
 
import gevent, socket, sys, time
 
def task(addr):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.settimeout(100)
    try:
        sock.connect(addr)
        print('Port ' + str(str(addr[1])) + ' is  open')
    except:
        pass
    finally:
        sock.close()
         
#扫描1000个端口
def asynchronous():
    threads = []
    for i in range(0, 1000):
        threads.append(gevent.spawn(task, ('127.0.0.1', i)))
    gevent.joinall(threads)
 
t0 = time.time()
asynchronous()
t1 = time.time()
print('time: {}s'.format(t1 - t0))

2. Trip+Requests实现爬虫代理验证：

import re
import trip

def get_proxies(number=10):
    r = yield trip.get('http://www.89ip.cn/apijk/' +
        '?&tqsl=%s&sxa=&sxb=&tta=&ports=&ktip=&cf=1' % number)
    p = re.findall('((?:\d{1,3}.){3}\d{1,3}:\d+)', r.text)
    print(p)

trip.run(get_proxies) 

import re, time

import requests, trip

@trip.coroutine
def get_proxies(number=10):
    r = yield trip.get('http://www.89ip.cn/apijk/' +
        '?&tqsl=%s&sxa=&sxb=&tta=&ports=&ktip=&cf=1' % number)
    p = re.findall('((?:\d{1,3}.){3}\d{1,3}:\d+)', r.text)
    raise trip.Return(p)

@trip.coroutine
def test_proxy(proxy):
    try:
        r = yield trip.get('http://httpbin.org/get', timeout=5,
            proxies={ 'http': proxy, 'https': proxy })
        if 'httpbin.org' not in r.text:
            raise Exception('Invalid reply')
    except Exception as e:
        pass
    else:
        raise trip.Return(proxy)

def main():
    proxies = yield get_proxies(100)
    r = yield [test_proxy(p) for p in proxies]
    print(filter(lambda x: x, r))

start_time = time.time()
trip.run(main)
print(time.time() - start_time)