廖雪峰Python Day-2代码解析

• 源代码

import logging; logging.basicConfig(level=logging.INFO)import asyncio, os, json, timefrom datetime import datetimefrom aiohttp import webdef index(request):    return web.Response(body=b'<h1>Awesome</h1>')@asyncio.coroutinedef init(loop):    app = web.Application(loop=loop)    app.router.add_route('GET', '/', index)    srv = yield from loop.create_server(app.make_handler(), '127.0.0.1', 9000)    logging.info('server started at http://127.0.0.1:9000...')    return srvloop = asyncio.get_event_loop()loop.run_until_complete(init(loop))loop.run_forever()

• 代码解析
  
  • def index(request):
return web.Response(body=b'<h1>Awesome</h1>')
    
    • request为aiohttp.web.request实例, 包含http请求的信息, 一般不用自己构造
    • web.Response 构造并返回一个response实例, Response类声明为class aiohttp.web.Response(*, status=200, headers=None, content_type=None, body=None, text=None)
  • @asyncio.coroutine将generator标记为coroutine类型, coroutine内部可以用yield from调用另一个coroutine
  • app = web.Application(loop=loop) 创建web服务器实例
    
    • loop: event loop used for processing HTTP requests
    • web.Application用法
  • app.router.add_route('GET', '/', index) 为route路径注册处理函数
  • srv = yield from loop.create_server(app.make_handler(), '127.0.0.1', 9000)
    
    • loop.create_server创建一个TCP server
    • app.make_handler() Creates HTTP protocol factory for handling requests.
    • yield from返回一个创建好的,绑定IP和端口以及http协议簇的监听服务的协程
  • loop = asyncio.get_event_loop() 生成一个事件循环实例
    loop.run_until_complete(init(loop)) 运行init(loop), run_until_complete: If the argument is a coroutine object, it is wrapped by ensure_future().对loop进行了初始化, 创建了tcp server?
    loop.run_forever()一直运行
• 引用
  
  • 廖雪峰Python教程Day2
  • Go-coding的博客
  • aiohttp官方文档
  • python官方文档