tornado 学习手册1

Tornado（5.1+ ）

Hello world

搭建一个简答的web app

hello_world.py

#!/usr/bin/python

# coding=utf-8

"""

tornado demo 1 简单的hello world web app

"""

import sys

import logging

import tornado.ioloop

import tornado.web

class MainHandler(tornado.web.RequestHandler):

def get(self):

self.write("hello world")

url = [(r'/', MainHandler),

]

def app():

global url

return tornado.web.Application(url)

if __name__ == "__main__":

logging.getLogger().handlers = []

logging.basicConfig(stream=sys.stdout, level=logging.DEBUG,

format='%(asctime)s %(levelname)s %(message)s')

ap = app()

ap.listen(9991)

logging.info("starting ....")

tornado.ioloop.IOLoop.current().start()

logging.info("end.")

使用python 启动后，在浏览器访问

python hello_world.py

安装

使用pip源安装

pip install tornado

依赖：

tornado6.0依赖python3.5.2或者更新版本不支持python2（5.1可以支持2.7和3.4+）。

Pycurl : 用来优化tornado.curl_httpclient，libcurl version 7.22或者更高版本

Twisted： may be used with the classes in [**tornado.platform.twisted**](https://www.tornadoweb.org/en/branch5.1/twisted.html#module-tornado.platform.twisted).

pycares： is an alternative non-blocking DNS resolver that can be used when threads are not appropriate.

• monotonic or Monotime ： add support for a monotonic clock, which improves reliability in environments where clock adjustments are frequent. No longer needed in Python 3.

平台： unix-like , 生产环境建议使用Linux（epoll）和BSD（kqueue），发挥最佳性能和伸缩性。window也可以用来开发，官方不建议使用生产。若果不重写IOLoop interface，可能无法添加原声的tornado windows OPLoop实现或者无法发挥windows的IOCP在类似asyncIO或者twisted框架中。

线程和WSGI

tornado不同于其他的很多python web 框架，他不基于WSGI，并且典型的是他只会在每个进程启动一个线程。感兴趣的可以查看更多的异步编程的方法。

While some support of WSGI is available in the [tornado.wsgi](https://www.tornadoweb.org/en/branch5.1/wsgi.html#module-tornado.wsgi) module, it is not a focus of development and most applications should be written to use Tornado’s own interfaces (such as [tornado.web](https://www.tornadoweb.org/en/branch5.1/web.html#module-tornado.web)) directly instead of using WSGI.

通常，tornado的code不是线程安全的。唯一的安全方方法是从其他的线程中调用IOLop.add_callback。（In general, Tornado code is not thread-safe. The only method in Tornado that is safe to call from other threads is [IOLoop.add_callback](https://www.tornadoweb.org/en/branch5.1/ioloop.html#tornado.ioloop.IOLoop.add_callback). You can also use [IOLoop.run_in_executor](https://www.tornadoweb.org/en/branch5.1/ioloop.html#tornado.ioloop.IOLoop.run_in_executor) to asynchronously run a blocking function on another thread, but note that the function passed to run_in_executor should avoid referencing any Tornado objects. run_in_executor is the recommended way to interact with blocking code.）

异步io集成

tornado集成了标准库asyncio模块，并且共享了相同的event loop（since 5.0 版本）。所以基于asncio设计的库都可以和tornado自由融合使用。

学习文档

Documentation

This documentation is also available in PDF and Epub formats.

• User’s guide

  • Introduction

  • Asynchronous and non-Blocking I/O

  • Coroutines

  • Queue example - a concurrent web spider

  • Structure of a Tornado web application

  • Templates and UI

  • Authentication and security

  • Running and deploying

• Web framework

  • tornado.web — RequestHandler and Application classes

  • tornado.template — Flexible output generation

  • tornado.routing — Basic routing implementation

  • tornado.escape — Escaping and string manipulation

  • tornado.locale — Internationalization support

  • tornado.websocket — Bidirectional communication to the browser

• HTTP servers and clients

  • tornado.httpserver — Non-blocking HTTP server

  • tornado.httpclient — Asynchronous HTTP client

  • tornado.httputil — Manipulate HTTP headers and URLs

  • tornado.http1connection – HTTP/1.x client/server implementation

• Asynchronous networking

  • tornado.ioloop — Main event loop

  • tornado.iostream — Convenient wrappers for non-blocking sockets

  • tornado.netutil — Miscellaneous network utilities

  • tornado.tcpclient — IOStream connection factory

  • tornado.tcpserver — Basic IOStream-based TCP server

• Coroutines and concurrency

  • tornado.gen — Generator-based coroutines

  • tornado.locks – Synchronization primitives

  • tornado.queues – Queues for coroutines

  • tornado.process — Utilities for multiple processes

• Integration with other services

  • tornado.auth — Third-party login with OpenID and OAuth

  • tornado.wsgi — Interoperability with other Python frameworks and servers

  • tornado.platform.caresresolver — Asynchronous DNS Resolver using C-Ares

  • tornado.platform.twisted — Bridges between Twisted and Tornado

  • tornado.platform.asyncio — Bridge between asyncio and Tornado

• Utilities

  • tornado.autoreload — Automatically detect code changes in development

  • tornado.concurrent — Work with Future objects

  • tornado.log — Logging support

  • tornado.options — Command-line parsing

  • tornado.stack_context — Exception handling across asynchronous callbacks

  • tornado.testing — Unit testing support for asynchronous code

  • tornado.util — General-purpose utilities

• Frequently Asked Questions