python中使用asyncio实现异步IO

import asyncio

@asyncio.coroutine

def wget(host):

    print('wget %s...' % host)

    connect = asyncio.open_connection(host, 80)

    reader, writer = yield from connect

    header = 'GET / HTTP/1.0\r\nHost: %s\r\n\r\n' % host

    writer.write(header.encode('utf-8'))

    yield from writer.drain()

    while True:

        line = yield from reader.readline()

        if line == b'\r\n':

            break

        print('%s header > %s' % (host, line.decode('utf-8').rstrip()))

    # Ignore the body, close the socket

    writer.close()

loop = asyncio.get_event_loop()

tasks = [wget(host) for host in ['www.sina.com.cn', 'www.sohu.com', 'www.163.com']]

loop.run_until_complete(asyncio.wait(tasks))

loop.close()