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#!/usr.bin.env python 3

# -*- coding: utf-8 -*-

'''

练习python的asyncio

yield form 语句返回的值是后面表达式迭代后遇到StopIteration后再return（这个语句）的值，无这个语句是返回None

'''

__author__ = 'sergiojune'

import asyncio,threading

@asyncio.coroutine # 这个装饰器是把生成器标记成为coroutine

def hello():

r = ''

print('hello world(%s)' % threading.current_thread())

n = yield from asyncio.sleep(1) # 这个方法也是个coroutine,执行到这里后会等待该方法返回数给这个coroutine

print('hello again(%s)' % threading.current_thread())

# 这是练习一个协程的

# # 获取事件循环，就是eventloop

# loop = asyncio.get_event_loop()

# # 执行coroutine,参数是需要运行的协程

# loop.run_until_complete(hello())

# # 关闭

# loop.close()

# 这个执行两个hello

# l = asyncio.get_event_loop()

# # 把协程放到eventloop里面

# # 这两个方法是并发执行的

# l.run_until_complete(asyncio.wait([hello(), hello()])) # wait()是将参数里的协程转为一个包括他们在内的单独协程

# l.close()

# 练习用异步连接新浪搜狐和网易云

def wget(host):

print('ready ro connect %s' % host)

connect = asyncio.open_connection(host, 80)

reader, writer = yield from connect # 这个io操作比较耗时，所以会执行下个协程

header = 'GET/HTTP/1.1\r\nHost:%s\r\n\r\n' % host

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

yield from writer.drain() # 用于刷新缓存区的内容，确保将内容提交上去

while True:

line = yield from reader.readline() # 这个io操作有时不耗时，会直接运行整个循环

if line == b'\r\n':

break

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

writer.close()

loop = asyncio.get_event_loop()

loop.run_until_complete(asyncio.wait([wget(host) for host in ['www.sina.com.cn', 'www.sohu.com', 'www.163.com']]))

loop.close()