Python教程

Python之路【第十八篇】:Web框架们

本文主要是介绍Python之路【第十八篇】:Web框架们,对大家解决编程问题具有一定的参考价值,需要的程序猿们随着小编来一起学习吧!

Python的WEB框架

Bottle

Bottle是一个快速、简洁、轻量级的基于WSIG的微型Web框架,此框架只由一个 .py 文件,除了Python的标准库外,其不依赖任何其他模块。

1 2 3 4 pip install bottle easy_install bottle apt-get install python-bottle wget http://bottlepy.org/bottle.py

Bottle框架大致可以分为以下部分:

  • 路由系统,将不同请求交由指定函数处理
  • 模板系统,将模板中的特殊语法渲染成字符串,值得一说的是Bottle的模板引擎可以任意指定:Bottle内置模板、mako、jinja2、cheetah
  • 公共组件,用于提供处理请求相关的信息,如:表单数据、cookies、请求头等
  • 服务,Bottle默认支持多种基于WSGI的服务,如:
    1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 server_names = {     'cgi': CGIServer,     'flup': FlupFCGIServer,     'wsgiref': WSGIRefServer,     'waitress': WaitressServer,     'cherrypy': CherryPyServer,     'paste': PasteServer,     'fapws3': FapwsServer,     'tornado': TornadoServer,     'gae': AppEngineServer,     'twisted': TwistedServer,     'diesel': DieselServer,     'meinheld': MeinheldServer,     'gunicorn': GunicornServer,     'eventlet': EventletServer,     'gevent': GeventServer,     'geventSocketIO':GeventSocketIOServer,     'rocket': RocketServer,     'bjoern' : BjoernServer,     'auto': AutoServer, }

框架的基本使用

1 2 3 4 5 6 7 8 9 10 11 #!/usr/bin/env python # -*- coding:utf-8 -*- from bottle import template, Bottle root = Bottle()   @root.route('/hello/') def index():     return "Hello World"     # return template('<b>Hello {{name}}</b>!', name="Alex")   root.run(host='localhost', port=8080)

一、路由系统

路由系统是的url对应指定函数,当用户请求某个url时,就由指定函数处理当前请求,对于Bottle的路由系统可以分为一下几类:

  • 静态路由
  • 动态路由
  • 请求方法路由
  • 二级路由

1、静态路由

1 2 3 @root.route('/hello/') def index():     return template('<b>Hello {{name}}</b>!', name="Alex")

2、动态路由

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 @root.route('/wiki/<pagename>') def callback(pagename):     ...   @root.route('/object/<id:int>') def callback(id):     ...   @root.route('/show/<name:re:[a-z]+>') def callback(name):     ...   @root.route('/static/<path:path>') def callback(path):     return static_file(path, root='static')

3、请求方法路由

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 @root.route('/hello/', method='POST') def index():     ...   @root.get('/hello/') def index():     ...   @root.post('/hello/') def index():     ...   @root.put('/hello/') def index():     ...   @root.delete('/hello/') def index():     ...

4、二级路由

1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 from bottle import template, Bottle
4 
5 app01 = Bottle()
6 
7 @app01.route('/hello/', method='GET')
8 def index():
9     return template('<b>App01</b>!')
app01.py
 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 from bottle import template, Bottle
 4 
 5 app02 = Bottle()
 6 
 7 
 8 @app02.route('/hello/', method='GET')
 9 def index():
10     return template('<b>App02</b>!')
app02.py

 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 #!/usr/bin/env python # -*- coding:utf-8 -*- from bottle import template, Bottle from bottle import static_file root = Bottle()   @root.route('/hello/') def index():     return template('<b>Root {{name}}</b>!', name="Alex")   from framwork_bottle import app01 from framwork_bottle import app02   root.mount('app01', app01.app01) root.mount('app02', app02.app02)   root.run(host='localhost', port=8080)

二、模板系统

模板系统用于将Html和自定的值两者进行渲染,从而得到字符串,然后将该字符串返回给客户端。我们知道在Bottle中可以使用 内置模板系统、mako、jinja2、cheetah等,以内置模板系统为例:

 1 <!DOCTYPE html>
 2 <html>
 3 <head lang="en">
 4     <meta charset="UTF-8">
 5     <title></title>
 6 </head>
 7 <body>
 8     <h1>{{name}}</h1>
 9 </body>
10 </html>
hello_template.tpl
1 2 3 4 5 6 7 8 9 10 11 12 #!/usr/bin/env python # -*- coding:utf-8 -*- from bottle import template, Bottle root = Bottle()   @root.route('/hello/') def index():     # 默认情况下去目录:['./', './views/']中寻找模板文件 hello_template.html     # 配置在 bottle.TEMPLATE_PATH 中     return template('hello_template.tpl', name='alex')   root.run(host='localhost', port=8080)

1、语法

  • 单值
  • 单行Python代码
  • Python代码快
  • Python、Html混合
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 <h1>1、单值</h1> {{name}}   <h1>2、单行Python代码</h1> % s1 = "hello"     <h1>3、Python代码块</h1> <%     # A block of python code     name = name.title().strip()     if name == "Alex":         name="seven" %>     <h1>4、Python、Html混合</h1>   % if True:     <span>{{name}}</span> % end <ul>   % for item in name:     <li>{{item}}</li>   % end </ul>

2、函数 

include(sub_template, **variables)

1 2 3 4 5 # 导入其他模板文件   % include('header.tpl', title='Page Title') Page Content % include('footer.tpl')

rebase(name, **variables)

1 <html>
2 <head>
3   <title>{{title or 'No title'}}</title>
4 </head>
5 <body>
6   {{!base}}
7 </body>
8 </html>
base.tpl

 

1 2 3 4 # 导入母版   % rebase('base.tpl', title='Page Title') <p>Page Content ...</p>

defined(name)

1 # 检查当前变量是否已经被定义,已定义True,未定义False

get(name, default=None)

1 # 获取某个变量的值,不存在时可设置默认值

setdefault(name, default)

1 # 如果变量不存在时,为变量设置默认值

扩展:自定义函数

 1 <!DOCTYPE html>
 2 <html>
 3 <head lang="en">
 4     <meta charset="UTF-8">
 5     <title></title>
 6 </head>
 7 <body>
 8     <h1>自定义函数</h1>
 9     {{ wupeiqi() }}
10 
11 </body>
12 </html>
hello_template.tpl
 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 from bottle import template, Bottle,SimpleTemplate
 4 root = Bottle()
 5 
 6 
 7 def custom():
 8     return '123123'
 9 
10 
11 @root.route('/hello/')
12 def index():
13     # 默认情况下去目录:['./', './views/']中寻找模板文件 hello_template.html
14     # 配置在 bottle.TEMPLATE_PATH 中
15     return template('hello_template.html', name='alex', wupeiqi=custom)
16 
17 root.run(host='localhost', port=8080)
main.py

注:变量或函数前添加 【 ! 】,则会关闭转义的功能

三、公共组件

由于Web框架就是用来【接收用户请求】-> 【处理用户请求】-> 【响应相关内容】,对于具体如何处理用户请求,开发人员根据用户请求来进行处理,而对于接收用户请求和相应相关的内容均交给框架本身来处理,其处理完成之后将产出交给开发人员和用户。

【接收用户请求】

当框架接收到用户请求之后,将请求信息封装在Bottle的request中,以供开发人员使用

【响应相关内容】

当开发人员的代码处理完用户请求之后,会将其执行内容相应给用户,相应的内容会封装在Bottle的response中,然后再由框架将内容返回给用户

所以,公共组件本质其实就是为开发人员提供接口,使其能够获取用户信息并配置响应内容。

1、request

Bottle中的request其实是一个LocalReqeust对象,其中封装了用户请求的相关信息:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 request.headers     请求头信息   request.query     get请求信息   request.forms     post请求信息   request.files     上传文件信息   request.params     get和post请求信息   request.GET     get请求信息   request.POST     post和上传信息   request.cookies     cookie信息       request.environ     环境相关相关

2、response

Bottle中的request其实是一个LocalResponse对象,其中框架即将返回给用户的相关信息:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 response     response.status_line         状态行       response.status_code         状态码       response.headers         响应头       response.charset         编码       response.set_cookie         在浏览器上设置cookie               response.delete_cookie         在浏览器上删除cookie

实例:

 1 from bottle import route, request
 2 
 3 @route('/login')
 4 def login():
 5     return '''
 6         <form action="/login" method="post">
 7             Username: <input name="username" type="text" />
 8             Password: <input name="password" type="password" />
 9             <input value="Login" type="submit" />
10         </form>
11     '''
12 
13 @route('/login', method='POST')
14 def do_login():
15     username = request.forms.get('username')
16     password = request.forms.get('password')
17     if check_login(username, password):
18         return "<p>Your login information was correct.</p>"
19     else:
20         return "<p>Login failed.</p>"
基本Form请求
 1 <form action="/upload" method="post" enctype="multipart/form-data">
 2   Category:      <input type="text" name="category" />
 3   Select a file: <input type="file" name="upload" />
 4   <input type="submit" value="Start upload" />
 5 </form>
 6 
 7 
 8 @route('/upload', method='POST')
 9 def do_upload():
10     category   = request.forms.get('category')
11     upload     = request.files.get('upload')
12     name, ext = os.path.splitext(upload.filename)
13     if ext not in ('.png','.jpg','.jpeg'):
14         return 'File extension not allowed.'
15 
16     save_path = get_save_path_for_category(category)
17     upload.save(save_path) # appends upload.filename automatically
18     return 'OK'
上传文件

四、服务

对于Bottle框架其本身未实现类似于Tornado自己基于socket实现Web服务,所以必须依赖WSGI,默认Bottle已经实现并且支持的WSGI有:

 1 server_names = {
 2     'cgi': CGIServer,
 3     'flup': FlupFCGIServer,
 4     'wsgiref': WSGIRefServer,
 5     'waitress': WaitressServer,
 6     'cherrypy': CherryPyServer,
 7     'paste': PasteServer,
 8     'fapws3': FapwsServer,
 9     'tornado': TornadoServer,
10     'gae': AppEngineServer,
11     'twisted': TwistedServer,
12     'diesel': DieselServer,
13     'meinheld': MeinheldServer,
14     'gunicorn': GunicornServer,
15     'eventlet': EventletServer,
16     'gevent': GeventServer,
17     'geventSocketIO':GeventSocketIOServer,
18     'rocket': RocketServer,
19     'bjoern' : BjoernServer,
20     'auto': AutoServer,
21 }
WSGI

使用时,只需在主app执行run方法时指定参数即可:

1 2 3 4 5 6 7 8 9 10 #!/usr/bin/env python # -*- coding:utf-8 -*- from bottle import Bottle root = Bottle()   @root.route('/hello/') def index():     return "Hello World" # 默认server ='wsgiref' root.run(host='localhost', port=8080, server='wsgiref')

默认server="wsgiref",即:使用Python内置模块wsgiref,如果想要使用其他时,则需要首先安装相关类库,然后才能使用。如:

 1 # 如果使用Tornado的服务,则需要首先安装tornado才能使用
 2 
 3 class TornadoServer(ServerAdapter):
 4     """ The super hyped asynchronous server by facebook. Untested. """
 5     def run(self, handler): # pragma: no cover
 6         # 导入Tornado相关模块
 7         import tornado.wsgi, tornado.httpserver, tornado.ioloop
 8         container = tornado.wsgi.WSGIContainer(handler)
 9         server = tornado.httpserver.HTTPServer(container)
10         server.listen(port=self.port,address=self.host)
11         tornado.ioloop.IOLoop.instance().start()
bottle.py源码

PS:以上WSGI中提供了19种,如果想要使期支持其他服务,则需要扩展Bottle源码来自定义一个ServerAdapter

更多参见:http://www.bottlepy.org/docs/dev/index.html

Flask 

Flask是一个基于Python开发并且依赖jinja2模板和Werkzeug WSGI服务的一个微型框架,对于Werkzeug本质是Socket服务端,其用于接收http请求并对请求进行预处理,然后触发Flask框架,开发人员基于Flask框架提供的功能对请求进行相应的处理,并返回给用户,如果要返回给用户复杂的内容时,需要借助jinja2模板来实现对模板的处理,即:将模板和数据进行渲染,将渲染后的字符串返回给用户浏览器。

“微”(micro) 并不表示你需要把整个 Web 应用塞进单个 Python 文件(虽然确实可以 ),也不意味着 Flask 在功能上有所欠缺。微框架中的“微”意味着 Flask 旨在保持核心简单而易于扩展。Flask 不会替你做出太多决策——比如使用何种数据库。而那些 Flask 所选择的——比如使用何种模板引擎——则很容易替换。除此之外的一切都由可由你掌握。如此,Flask 可以与您珠联璧合。

默认情况下,Flask 不包含数据库抽象层、表单验证,或是其它任何已有多种库可以胜任的功能。然而,Flask 支持用扩展来给应用添加这些功能,如同是 Flask 本身实现的一样。众多的扩展提供了数据库集成、表单验证、上传处理、各种各样的开放认证技术等功能。Flask 也许是“微小”的,但它已准备好在需求繁杂的生产环境中投入使用。

安装

1 pip install Flask
 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 from werkzeug.wrappers import Request, Response
 4 
 5 @Request.application
 6 def hello(request):
 7     return Response('Hello World!')
 8 
 9 if __name__ == '__main__':
10     from werkzeug.serving import run_simple
11     run_simple('localhost', 4000, hello)
werkzeug

一、第一次

1 2 3 4 5 6 7 8 9 from flask import Flask app = Flask(__name__)   @app.route("/") def hello():     return "Hello World!"   if __name__ == "__main__":     app.run()

二、路由系统

  • @app.route('/user/<username>')
  • @app.route('/post/<int:post_id>')
  • @app.route('/post/<float:post_id>')
  • @app.route('/post/<path:path>')
  • @app.route('/login', methods=['GET', 'POST'])

常用路由系统有以上五种,所有的路由系统都是基于一下对应关系来处理:

1 2 3 4 5 6 7 8 9 DEFAULT_CONVERTERS = {     'default':          UnicodeConverter,     'string':           UnicodeConverter,     'any':              AnyConverter,     'path':             PathConverter,     'int':              IntegerConverter,     'float':            FloatConverter,     'uuid':             UUIDConverter, }

注:对于Flask默认不支持直接写正则表达式的路由,不过可以通过自定义来实现,见:https://segmentfault.com/q/1010000000125259

三、模板

1、模板的使用

Flask使用的是Jinja2模板,所以其语法和Django无差别

2、自定义模板方法

Flask中自定义模板方法的方式和Bottle相似,创建一个函数并通过参数的形式传入render_template,如:

 1 <!DOCTYPE html>
 2 <html>
 3 <head lang="en">
 4     <meta charset="UTF-8">
 5     <title></title>
 6 </head>
 7 <body>
 8     <h1>自定义函数</h1>
 9     {{ww()|safe}}
10 
11 </body>
12 </html>
index.html
1 2 3 4 5 6 7 8 9 10 11 12 13 14 #!/usr/bin/env python # -*- coding:utf-8 -*- from flask import Flask,render_template app = Flask(__name__)     def wupeiqi():     return '<h1>Wupeiqi</h1>'   @app.route('/login', methods=['GET''POST']) def login():     return render_template('login.html', ww=wupeiqi)   app.run()

四、公共组件

1、请求

对于Http请求,Flask会讲请求信息封装在request中(werkzeug.wrappers.BaseRequest),提供的如下常用方法和字段以供使用:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 request.method request.args request.form request.values request.files request.cookies request.headers request.path request.full_path request.script_root request.url request.base_url request.url_root request.host_url request.host
 1 @app.route('/login', methods=['POST', 'GET'])
 2 def login():
 3     error = None
 4     if request.method == 'POST':
 5         if valid_login(request.form['username'],
 6                        request.form['password']):
 7             return log_the_user_in(request.form['username'])
 8         else:
 9             error = 'Invalid username/password'
10     # the code below is executed if the request method
11     # was GET or the credentials were invalid
12     return render_template('login.html', error=error)
表单处理Demo
1 from flask import request
2 from werkzeug import secure_filename
3 
4 @app.route('/upload', methods=['GET', 'POST'])
5 def upload_file():
6     if request.method == 'POST':
7         f = request.files['the_file']
8         f.save('/var/www/uploads/' + secure_filename(f.filename))
9     ...
上传文件Demo
 1 from flask import request
 2 
 3 @app.route('/setcookie/')
 4 def index():
 5     username = request.cookies.get('username')
 6     # use cookies.get(key) instead of cookies[key] to not get a
 7     # KeyError if the cookie is missing.
 8 
 9 
10 
11 
12 from flask import make_response
13 
14 @app.route('/getcookie')
15 def index():
16     resp = make_response(render_template(...))
17     resp.set_cookie('username', 'the username')
18     return resp
Cookie操作

2、响应

当用户请求被开发人员的逻辑处理完成之后,会将结果发送给用户浏览器,那么就需要对请求做出相应的响应。

a.字符串

1 2 3 @app.route('/index/', methods=['GET''POST']) def index():     return "index"

b.模板引擎

1 2 3 4 5 6 7 8 from flask import Flask,render_template,request app = Flask(__name__)   @app.route('/index/', methods=['GET''POST']) def index():     return render_template("index.html")   app.run()

c.重定向

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 #!/usr/bin/env python # -*- coding:utf-8 -*- from flask import Flask, redirect, url_for app = Flask(__name__)   @app.route('/index/', methods=['GET''POST']) def index():     # return redirect('/login/')     return redirect(url_for('login'))   @app.route('/login/', methods=['GET''POST']) def login():     return "LOGIN"   app.run()

d.错误页面

1 from flask import Flask, abort, render_template
2 app = Flask(__name__)
3 
4 @app.route('/e1/', methods=['GET', 'POST'])
5 def index():
6     abort(404, 'Nothing')
7 app.run()
指定URL,简单错误
1 2 3 4 5 6 7 8 9 10 11 12 from flask import Flask, abort, render_template app = Flask(__name__)   @app.route('/index/', methods=['GET''POST']) def index():     return "OK"   @app.errorhandler(404) def page_not_found(error):     return render_template('page_not_found.html'), 404   app.run()

e.设置相应信息

使用make_response可以对相应的内容进行操作

1 2 3 4 5 6 7 8 9 10 11 12 13 from flask import Flask, abort, render_template,make_response app = Flask(__name__)   @app.route('/index/', methods=['GET''POST']) def index():     response = make_response(render_template('index.html'))     # response是flask.wrappers.Response类型     # response.delete_cookie     # response.set_cookie     # response.headers['X-Something'] = 'A value'     return response   app.run()

3、Session

除请求对象之外,还有一个 session 对象。它允许你在不同请求间存储特定用户的信息。它是在 Cookies 的基础上实现的,并且对 Cookies 进行密钥签名要使用会话,你需要设置一个密钥。

  • 设置:session['username'] = 'xxx'

  • 删除:session.pop('username', None)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 from flask import Flask, session, redirect, url_for, escape, request   app = Flask(__name__)   @app.route('/') def index():     if 'username' in session:         return 'Logged in as %s' % escape(session['username'])     return 'You are not logged in'   @app.route('/login', methods=['GET''POST']) def login():     if request.method == 'POST':         session['username'= request.form['username']         return redirect(url_for('index'))     return '''         <form action="" method="post">             <p><input type=text name=username>             <p><input type=submit value=Login>         </form>     '''   @app.route('/logout') def logout():     # remove the username from the session if it's there     session.pop('username'None)     return redirect(url_for('index'))   # set the secret key.  keep this really secret: app.secret_key = 'A0Zr98j/3yX R~XHH!jmN]LWX/,?RT'

4.message

message是一个基于Session实现的用于保存数据的集合,其特点是:使用一次就删除

 1 <!DOCTYPE html>
 2 <html>
 3 <head lang="en">
 4     <meta charset="UTF-8">
 5     <title></title>
 6 </head>
 7 <body>
 8     {% with messages = get_flashed_messages() %}
 9         {% if messages %}
10         <ul class=flashes>
11             {% for message in messages %}
12             <li>{{ message }}</li>
13             {% endfor %}
14         </ul>
15         {% endif %}
16     {% endwith %}
17 </body>
18 </html>
index.html
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 from flask import Flask, flash, redirect, render_template, request   app = Flask(__name__) app.secret_key = 'some_secret'   @app.route('/') def index1():     return render_template('index.html')   @app.route('/set') def index2():     = request.args.get('p')     flash(v)     return 'ok'   if __name__ == "__main__":     app.run()

5.中间件

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 from flask import Flask, flash, redirect, render_template, request   app = Flask(__name__) app.secret_key = 'some_secret'   @app.route('/') def index1():     return render_template('index.html')   @app.route('/set') def index2():     = request.args.get('p')     flash(v)     return 'ok'   class MiddleWare:     def __init__(self,wsgi_app):         self.wsgi_app = wsgi_app       def __call__(self*args, **kwargs):           return self.wsgi_app(*args, **kwargs)   if __name__ == "__main__":     app.wsgi_app = MiddleWare(app.wsgi_app)     app.run(port=9999)

Flask还有众多其他功能,更多参见:
    http://docs.jinkan.org/docs/flask/
    http://flask.pocoo.org/

Tornado

Tornado 是 FriendFeed 使用的可扩展的非阻塞式 web 服务器及其相关工具的开源版本。这个 Web 框架看起来有些像web.py 或者 Google 的 webapp,不过为了能有效利用非阻塞式服务器环境,这个 Web 框架还包含了一些相关的有用工具 和优化。

Tornado 和现在的主流 Web 服务器框架(包括大多数 Python 的框架)有着明显的区别:它是非阻塞式服务器,而且速度相当快。得利于其 非阻塞的方式和对 epoll 的运用,Tornado 每秒可以处理数以千计的连接,这意味着对于实时 Web 服务来说,Tornado 是一个理想的 Web 框架。我们开发这个 Web 服务器的主要目的就是为了处理 FriendFeed 的实时功能 ——在 FriendFeed 的应用里每一个活动用户都会保持着一个服务器连接。(关于如何扩容 服务器,以处理数以千计的客户端的连接的问题,请参阅 C10K problem。)

1 2 3 pip install tornado 源码安装     https://pypi.python.org/packages/source/t/tornado/tornado-4.3.tar.gz

一、快速上手

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 #!/usr/bin/env python # -*- coding:utf-8 -*-    import tornado.ioloop import tornado.web       class MainHandler(tornado.web.RequestHandler):     def get(self):         self.write("Hello, world")    application = tornado.web.Application([     (r"/index", MainHandler), ])       if __name__ == "__main__":     application.listen(8888)     tornado.ioloop.IOLoop.instance().start()

第一步:执行脚本,监听 8888 端口

第二步:浏览器客户端访问 /index  -->  http://127.0.0.1:8888/index

第三步:服务器接受请求,并交由对应的类处理该请求

第四步:类接受到请求之后,根据请求方式(post / get / delete ...)的不同调用并执行相应的方法

第五步:方法返回值的字符串内容发送浏览器

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #!/usr/bin/env python
 4 # -*- coding:utf-8 -*-
 5 
 6 import tornado.ioloop
 7 import tornado.web
 8 from tornado import httpclient
 9 from tornado.web import asynchronous
10 from tornado import gen
11 
12 import uimodules as md
13 import uimethods as mt
14 
15 class MainHandler(tornado.web.RequestHandler):
16         @asynchronous
17         @gen.coroutine
18         def get(self):
19             print 'start get '
20             http = httpclient.AsyncHTTPClient()
21             http.fetch("http://127.0.0.1:8008/post/", self.callback)
22             self.write('end')
23 
24         def callback(self, response):
25             print response.body
26 
27 settings = {
28     'template_path': 'template',
29     'static_path': 'static',
30     'static_url_prefix': '/static/',
31     'ui_methods': mt,
32     'ui_modules': md,
33 }
34 
35 application = tornado.web.Application([
36     (r"/index", MainHandler),
37 ], **settings)
38 
39 
40 if __name__ == "__main__":
41     application.listen(8009)
42     tornado.ioloop.IOLoop.instance().start()
异步非阻塞实例

二、路由系统

路由系统其实就是 url 和 类 的对应关系,这里不同于其他框架,其他很多框架均是 url 对应 函数,Tornado中每个url对应的是一个类。

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 #!/usr/bin/env python # -*- coding:utf-8 -*-    import tornado.ioloop import tornado.web       class MainHandler(tornado.web.RequestHandler):     def get(self):         self.write("Hello, world")    class StoryHandler(tornado.web.RequestHandler):     def get(self, story_id):         self.write("You requested the story " + story_id)    class BuyHandler(tornado.web.RequestHandler):     def get(self):         self.write("buy.wupeiqi.com/index")    application = tornado.web.Application([     (r"/index", MainHandler),     (r"/story/([0-9]+)", StoryHandler), ])    application.add_handlers('buy.wupeiqi.com$', [     (r'/index',BuyHandler), ])    if __name__ == "__main__":     application.listen(80)     tornado.ioloop.IOLoop.instance().start()

三、模板

Tornao中的模板语言和django中类似,模板引擎将模板文件载入内存,然后将数据嵌入其中,最终获取到一个完整的字符串,再将字符串返回给请求者。

Tornado 的模板支持“控制语句”和“表达语句”,控制语句是使用 {% 和 %} 包起来的 例如 {% if len(items) > 2 %}。表达语句是使用 {{ 和 }} 包起来的,例如 {{ items[0] }}

控制语句和对应的 Python 语句的格式基本完全相同。我们支持 ifforwhile 和 try,这些语句逻辑结束的位置需要用 {% end %} 做标记。还通过 extends 和 block 语句实现了模板继承。这些在 template 模块 的代码文档中有着详细的描述。

 1 <!DOCTYPE html>
 2 <html>
 3 <head>
 4     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
 5     <title>老男孩</title>
 6     <link href="{{static_url("css/common.css")}}" rel="stylesheet" />
 7     {% block CSS %}{% end %}
 8 </head>
 9 <body>
10 
11     <div class="pg-header">
12 
13     </div>
14     
15     {% block RenderBody %}{% end %}
16    
17     <script src="{{static_url("js/jquery-1.8.2.min.js")}}"></script>
18     
19     {% block JavaScript %}{% end %}
20 </body>
21 </html>
layout.html
 1 {% extends 'layout.html'%}
 2 {% block CSS %}
 3     <link href="{{static_url("css/index.css")}}" rel="stylesheet" />
 4 {% end %}
 5 
 6 {% block RenderBody %}
 7     <h1>Index</h1>
 8 
 9     <ul>
10     {%  for item in li %}
11         <li>{{item}}</li>
12     {% end %}
13     </ul>
14 
15 {% end %}
16 
17 {% block JavaScript %}
18     
19 {% end %}
index.html
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 #!/usr/bin/env python # -*- coding:utf-8 -*-    import tornado.ioloop import tornado.web       class MainHandler(tornado.web.RequestHandler):     def get(self):         self.render('home/index.html')    settings = {     'template_path''template', }    application = tornado.web.Application([     (r"/index", MainHandler), ], **settings)       if __name__ == "__main__":     application.listen(80)     tornado.ioloop.IOLoop.instance().start()

在模板中默认提供了一些函数、字段、类以供模板使用:

  • escapetornado.escape.xhtml_escape 的別名
  • xhtml_escapetornado.escape.xhtml_escape 的別名
  • url_escapetornado.escape.url_escape 的別名
  • json_encodetornado.escape.json_encode 的別名
  • squeezetornado.escape.squeeze 的別名
  • linkifytornado.escape.linkify 的別名
  • datetime: Python 的 datetime 模组
  • handler: 当前的 RequestHandler 对象
  • requesthandler.request 的別名
  • current_userhandler.current_user 的別名
  • localehandler.locale 的別名
  • _handler.locale.translate 的別名
  • static_url: for handler.static_url 的別名
  • xsrf_form_htmlhandler.xsrf_form_html 的別名

Tornado默认提供的这些功能其实本质上就是 UIMethod 和 UIModule,我们也可以自定义从而实现类似于Django的simple_tag的功能:
1、定义

1 # uimethods.py
2  
3 def tab(self):
4     return 'UIMethod'
uimethods.py
 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 from tornado.web import UIModule
 4 from tornado import escape
 5 
 6 class custom(UIModule):
 7 
 8     def render(self, *args, **kwargs):
 9         return escape.xhtml_escape('<h1>wupeiqi</h1>')
10         #return escape.xhtml_escape('<h1>wupeiqi</h1>')
uimodules.py

2、注册

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #!/usr/bin/env python
 4 # -*- coding:utf-8 -*-
 5 
 6 import tornado.ioloop
 7 import tornado.web
 8 from tornado.escape import linkify
 9 import uimodules as md
10 import uimethods as mt
11 
12 class MainHandler(tornado.web.RequestHandler):
13     def get(self):
14         self.render('index.html')
15 
16 settings = {
17     'template_path': 'template',
18     'static_path': 'static',
19     'static_url_prefix': '/static/',
20     'ui_methods': mt,
21     'ui_modules': md,
22 }
23 
24 application = tornado.web.Application([
25     (r"/index", MainHandler),
26 ], **settings)
27 
28 
29 if __name__ == "__main__":
30     application.listen(8009)
31     tornado.ioloop.IOLoop.instance().start()
main.py

3、使用

 1 <!DOCTYPE html>
 2 <html>
 3 <head lang="en">
 4     <meta charset="UTF-8">
 5     <title></title>
 6     <link href="{{static_url("commons.css")}}" rel="stylesheet" />
 7 </head>
 8 <body>
 9     <h1>hello</h1>
10     {% module custom(123) %}
11     {{ tab() }}
12 </body>
index.html

四、实用功能

1、静态文件

对于静态文件,可以配置静态文件的目录和前段使用时的前缀,并且Tornaodo还支持静态文件缓存。

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3  
 4 import tornado.ioloop
 5 import tornado.web
 6  
 7  
 8 class MainHandler(tornado.web.RequestHandler):
 9     def get(self):
10         self.render('home/index.html')
11  
12 settings = {
13     'template_path': 'template',
14     'static_path': 'static',
15     'static_url_prefix': '/static/',
16 }
17  
18 application = tornado.web.Application([
19     (r"/index", MainHandler),
20 ], **settings)
21  
22  
23 if __name__ == "__main__":
24     application.listen(80)
25     tornado.ioloop.IOLoop.instance().start()
main.py
 1 <!DOCTYPE html>
 2 <html>
 3 <head lang="en">
 4     <meta charset="UTF-8">
 5     <title></title>
 6     <link href="{{static_url("commons.css")}}" rel="stylesheet" />
 7 </head>
 8 <body>
 9     <h1>hello</h1>
10 </body>
11 </html>
index.html

备注:静态文件缓存的实现

 1 def get_content_version(cls, abspath):
 2         """Returns a version string for the resource at the given path.
 3 
 4         This class method may be overridden by subclasses.  The
 5         default implementation is a hash of the file's contents.
 6 
 7         .. versionadded:: 3.1
 8         """
 9         data = cls.get_content(abspath)
10         hasher = hashlib.md5()
11         if isinstance(data, bytes):
12             hasher.update(data)
13         else:
14             for chunk in data:
15                 hasher.update(chunk)
16         return hasher.hexdigest()
静态文件缓存源码

2、csrf

Tornado中的夸张请求伪造和Django中的相似,跨站伪造请求(Cross-site request forgery)

1 settings = {
2     "xsrf_cookies": True,
3 }
4 application = tornado.web.Application([
5     (r"/", MainHandler),
6     (r"/login", LoginHandler),
7 ], **settings)
配置
1 <form action="/new_message" method="post">
2   {{ xsrf_form_html() }}
3   <input type="text" name="message"/>
4   <input type="submit" value="Post"/>
5 </form>
普通表单使用
 1 function getCookie(name) {
 2     var r = document.cookie.match("\\b" + name + "=([^;]*)\\b");
 3     return r ? r[1] : undefined;
 4 }
 5 
 6 jQuery.postJSON = function(url, args, callback) {
 7     args._xsrf = getCookie("_xsrf");
 8     $.ajax({url: url, data: $.param(args), dataType: "text", type: "POST",
 9         success: function(response) {
10         callback(eval("(" + response + ")"));
11     }});
12 };
Ajax使用

注:Ajax使用时,本质上就是去获取本地的cookie,携带cookie再来发送请求

3、cookie

Tornado中可以对cookie进行操作,并且还可以对cookie进行签名以放置伪造。

a、基本操作

1 class MainHandler(tornado.web.RequestHandler):
2     def get(self):
3         if not self.get_cookie("mycookie"):
4             self.set_cookie("mycookie", "myvalue")
5             self.write("Your cookie was not set yet!")
6         else:
7             self.write("Your cookie was set!")
Code

b、签名

Cookie 很容易被恶意的客户端伪造。加入你想在 cookie 中保存当前登陆用户的 id 之类的信息,你需要对 cookie 作签名以防止伪造。Tornado 通过 set_secure_cookie 和 get_secure_cookie 方法直接支持了这种功能。 要使用这些方法,你需要在创建应用时提供一个密钥,名字为 cookie_secret。 你可以把它作为一个关键词参数传入应用的设置中:

 1 class MainHandler(tornado.web.RequestHandler):
 2     def get(self):
 3         if not self.get_secure_cookie("mycookie"):
 4             self.set_secure_cookie("mycookie", "myvalue")
 5             self.write("Your cookie was not set yet!")
 6         else:
 7             self.write("Your cookie was set!")
 8              
 9 application = tornado.web.Application([
10     (r"/", MainHandler),
11 ], cookie_secret="61oETzKXQAGaYdkL5gEmGeJJFuYh7EQnp2XdTP1o/Vo=")
Code
 1 def _create_signature_v1(secret, *parts):
 2     hash = hmac.new(utf8(secret), digestmod=hashlib.sha1)
 3     for part in parts:
 4         hash.update(utf8(part))
 5     return utf8(hash.hexdigest())
 6 
 7 
 8 def _create_signature_v2(secret, s):
 9     hash = hmac.new(utf8(secret), digestmod=hashlib.sha256)
10     hash.update(utf8(s))
11     return utf8(hash.hexdigest())
内部算法
 1 def create_signed_value(secret, name, value, version=None, clock=None,
 2                         key_version=None):
 3     if version is None:
 4         version = DEFAULT_SIGNED_VALUE_VERSION
 5     if clock is None:
 6         clock = time.time
 7 
 8     timestamp = utf8(str(int(clock())))
 9     value = base64.b64encode(utf8(value))
10     if version == 1:
11         signature = _create_signature_v1(secret, name, value, timestamp)
12         value = b"|".join([value, timestamp, signature])
13         return value
14     elif version == 2:
15         # The v2 format consists of a version number and a series of
16         # length-prefixed fields "%d:%s", the last of which is a
17         # signature, all separated by pipes.  All numbers are in
18         # decimal format with no leading zeros.  The signature is an
19         # HMAC-SHA256 of the whole string up to that point, including
20         # the final pipe.
21         #
22         # The fields are:
23         # - format version (i.e. 2; no length prefix)
24         # - key version (integer, default is 0)
25         # - timestamp (integer seconds since epoch)
26         # - name (not encoded; assumed to be ~alphanumeric)
27         # - value (base64-encoded)
28         # - signature (hex-encoded; no length prefix)
29         def format_field(s):
30             return utf8("%d:" % len(s)) + utf8(s)
31         to_sign = b"|".join([
32             b"2",
33             format_field(str(key_version or 0)),
34             format_field(timestamp),
35             format_field(name),
36             format_field(value),
37             b''])
38 
39         if isinstance(secret, dict):
40             assert key_version is not None, 'Key version must be set when sign key dict is used'
41             assert version >= 2, 'Version must be at least 2 for key version support'
42             secret = secret[key_version]
43 
44         signature = _create_signature_v2(secret, to_sign)
45         return to_sign + signature
46     else:
47         raise ValueError("Unsupported version %d" % version)
内部算法-加密
 1 def _decode_signed_value_v1(secret, name, value, max_age_days, clock):
 2     parts = utf8(value).split(b"|")
 3     if len(parts) != 3:
 4         return None
 5     signature = _create_signature_v1(secret, name, parts[0], parts[1])
 6     if not _time_independent_equals(parts[2], signature):
 7         gen_log.warning("Invalid cookie signature %r", value)
 8         return None
 9     timestamp = int(parts[1])
10     if timestamp < clock() - max_age_days * 86400:
11         gen_log.warning("Expired cookie %r", value)
12         return None
13     if timestamp > clock() + 31 * 86400:
14         # _cookie_signature does not hash a delimiter between the
15         # parts of the cookie, so an attacker could transfer trailing
16         # digits from the payload to the timestamp without altering the
17         # signature.  For backwards compatibility, sanity-check timestamp
18         # here instead of modifying _cookie_signature.
19         gen_log.warning("Cookie timestamp in future; possible tampering %r",
20                         value)
21         return None
22     if parts[1].startswith(b"0"):
23         gen_log.warning("Tampered cookie %r", value)
24         return None
25     try:
26         return base64.b64decode(parts[0])
27     except Exception:
28         return None
29 
30 
31 def _decode_fields_v2(value):
32     def _consume_field(s):
33         length, _, rest = s.partition(b':')
34         n = int(length)
35         field_value = rest[:n]
36         # In python 3, indexing bytes returns small integers; we must
37         # use a slice to get a byte string as in python 2.
38         if rest[n:n + 1] != b'|':
39             raise ValueError("malformed v2 signed value field")
40         rest = rest[n + 1:]
41         return field_value, rest
42 
43     rest = value[2:]  # remove version number
44     key_version, rest = _consume_field(rest)
45     timestamp, rest = _consume_field(rest)
46     name_field, rest = _consume_field(rest)
47     value_field, passed_sig = _consume_field(rest)
48     return int(key_version), timestamp, name_field, value_field, passed_sig
49 
50 
51 def _decode_signed_value_v2(secret, name, value, max_age_days, clock):
52     try:
53         key_version, timestamp, name_field, value_field, passed_sig = _decode_fields_v2(value)
54     except ValueError:
55         return None
56     signed_string = value[:-len(passed_sig)]
57 
58     if isinstance(secret, dict):
59         try:
60             secret = secret[key_version]
61         except KeyError:
62             return None
63 
64     expected_sig = _create_signature_v2(secret, signed_string)
65     if not _time_independent_equals(passed_sig, expected_sig):
66         return None
67     if name_field != utf8(name):
68         return None
69     timestamp = int(timestamp)
70     if timestamp < clock() - max_age_days * 86400:
71         # The signature has expired.
72         return None
73     try:
74         return base64.b64decode(value_field)
75     except Exception:
76         return None
77 
78 
79 def get_signature_key_version(value):
80     value = utf8(value)
81     version = _get_version(value)
82     if version < 2:
83         return None
84     try:
85         key_version, _, _, _, _ = _decode_fields_v2(value)
86     except ValueError:
87         return None
88 
89     return key_version
内部算法-解密

签名Cookie的本质是:

写cookie过程:

  • 将值进行base64加密
  • 对除值以外的内容进行签名,哈希算法(无法逆向解析)
  • 拼接 签名 + 加密值

读cookie过程:

  • 读取 签名 + 加密值
  • 对签名进行验证
  • base64解密,获取值内容

注:许多API验证机制和安全cookie的实现机制相同。

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3  
 4 import tornado.ioloop
 5 import tornado.web
 6  
 7  
 8 class MainHandler(tornado.web.RequestHandler):
 9  
10     def get(self):
11         login_user = self.get_secure_cookie("login_user", None)
12         if login_user:
13             self.write(login_user)
14         else:
15             self.redirect('/login')
16  
17  
18 class LoginHandler(tornado.web.RequestHandler):
19     def get(self):
20         self.current_user()
21  
22         self.render('login.html', **{'status': ''})
23  
24     def post(self, *args, **kwargs):
25  
26         username = self.get_argument('name')
27         password = self.get_argument('pwd')
28         if username == 'wupeiqi' and password == '123':
29             self.set_secure_cookie('login_user', '武沛齐')
30             self.redirect('/')
31         else:
32             self.render('login.html', **{'status': '用户名或密码错误'})
33  
34 settings = {
35     'template_path': 'template',
36     'static_path': 'static',
37     'static_url_prefix': '/static/',
38     'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh'
39 }
40  
41 application = tornado.web.Application([
42     (r"/index", MainHandler),
43     (r"/login", LoginHandler),
44 ], **settings)
45  
46  
47 if __name__ == "__main__":
48     application.listen(8888)
49     tornado.ioloop.IOLoop.instance().start()
Demo-基于cookie进行用户验证
 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3  
 4 import tornado.ioloop
 5 import tornado.web
 6  
 7 class BaseHandler(tornado.web.RequestHandler):
 8  
 9     def get_current_user(self):
10         return self.get_secure_cookie("login_user")
11  
12 class MainHandler(BaseHandler):
13  
14     @tornado.web.authenticated
15     def get(self):
16         login_user = self.current_user
17         self.write(login_user)
18  
19  
20  
21 class LoginHandler(tornado.web.RequestHandler):
22     def get(self):
23         self.current_user()
24  
25         self.render('login.html', **{'status': ''})
26  
27     def post(self, *args, **kwargs):
28  
29         username = self.get_argument('name')
30         password = self.get_argument('pwd')
31         if username == 'wupeiqi' and password == '123':
32             self.set_secure_cookie('login_user', '武沛齐')
33             self.redirect('/')
34         else:
35             self.render('login.html', **{'status': '用户名或密码错误'})
36  
37 settings = {
38     'template_path': 'template',
39     'static_path': 'static',
40     'static_url_prefix': '/static/',
41     'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh',
42     'login_url': '/login'
43 }
44  
45 application = tornado.web.Application([
46     (r"/index", MainHandler),
47     (r"/login", LoginHandler),
48 ], **settings)
49  
50  
51 if __name__ == "__main__":
52     application.listen(8888)
53     tornado.ioloop.IOLoop.instance().start()
Demo-Toando内部提供基于cookie进行用户验证

4、Ajax上传文件

 1 <!DOCTYPE html>
 2 <html>
 3 <head lang="en">
 4     <meta charset="UTF-8">
 5     <title></title>
 6 </head>
 7 <body>
 8     <input type="file" id="img" />
 9     <input type="button" onclick="UploadFile();" />
10     <script>
11         function UploadFile(){
12             var fileObj = document.getElementById("img").files[0];
13 
14             var form = new FormData();
15             form.append("k1", "v1");
16             form.append("fff", fileObj);
17 
18             var xhr = new XMLHttpRequest();
19             xhr.open("post", '/index', true);
20             xhr.send(form);
21         }
22     </script>
23 </body>
24 </html>
Html
 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #!/usr/bin/env python
 4 # -*- coding:utf-8 -*-
 5 
 6 import tornado.ioloop
 7 import tornado.web
 8 
 9 
10 class MainHandler(tornado.web.RequestHandler):
11     def get(self):
12 
13         self.render('index.html')
14 
15     def post(self, *args, **kwargs):
16         file_metas = self.request.files["fff"]
17         # print(file_metas)
18         for meta in file_metas:
19             file_name = meta['filename']
20             with open(file_name,'wb') as up:
21                 up.write(meta['body'])
22 
23 settings = {
24     'template_path': 'template',
25 }
26 
27 application = tornado.web.Application([
28     (r"/index", MainHandler),
29 ], **settings)
30 
31 
32 if __name__ == "__main__":
33     application.listen(8000)
34     tornado.ioloop.IOLoop.instance().start()
Python
 1 var fileObj = $("#img")[0].files[0];
 2 var form = new FormData();
 3 form.append("k1", "v1");
 4 form.append("fff", fileObj);
 5 
 6 $.ajax({
 7     type:'POST',
 8     url: '/index',
 9     data: form,
10     processData: false,  // tell jQuery not to process the data
11     contentType: false,  // tell jQuery not to set contentType
12     success: function(arg){
13         console.log(arg);
14     }
15 })
jQuery Ajax Upload

五、扩展功能

1、自定义Session

a.知识储备

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 #!/usr/bin/env python # -*- coding:utf-8 -*-    class Foo(object):        def __getitem__(self, key):         print  '__getitem__',key        def __setitem__(self, key, value):         print '__setitem__',key,value        def __delitem__(self, key):         print '__delitem__',key          obj = Foo() result = obj['k1'] #obj['k2'] = 'wupeiqi' #del obj['k1']

b.session实现机制

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 #!/usr/bin/env python # -*- coding:utf-8 -*-    import tornado.ioloop import tornado.web from hashlib import sha1 import os, time    session_container = {}    create_session_id = lambda: sha1('%s%s' % (os.urandom(16), time.time())).hexdigest()       class Session(object):        session_id = "__sessionId__"        def __init__(self, request):         session_value = request.get_cookie(Session.session_id)         if not session_value:             self._id = create_session_id()         else:             self._id = session_value         request.set_cookie(Session.session_id, self._id)        def __getitem__(self, key):         return session_container[self._id][key]        def __setitem__(self, key, value):         if session_container.has_key(self._id):             session_container[self._id][key] = value         else:             session_container[self._id] = {key: value}        def __delitem__(self, key):         del session_container[self._id][key]       class BaseHandler(tornado.web.RequestHandler):        def initialize(self):         # my_session['k1']访问 __getitem__ 方法         self.my_session = Session(self)       class MainHandler(BaseHandler):        def get(self):         print self.my_session['c_user']         print self.my_session['c_card']         self.write('index')    class LoginHandler(BaseHandler):        def get(self):         self.render('login.html'**{'status': ''})        def post(self*args, **kwargs):            username = self.get_argument('name')         password = self.get_argument('pwd')         if username == 'wupeiqi' and password == '123':                self.my_session['c_user'= 'wupeiqi'             self.my_session['c_card'= '12312312309823012'                self.redirect('/index')         else:             self.render('login.html'**{'status''用户名或密码错误'})    settings = {     'template_path''template',     'static_path''static',     'static_url_prefix''/static/',     'cookie_secret''aiuasdhflashjdfoiuashdfiuh',     'login_url''/login' }    application = tornado.web.Application([     (r"/index", MainHandler),     (r"/login", LoginHandler), ], **settings)       if __name__ == "__main__":     application.listen(8888)     tornado.ioloop.IOLoop.instance().start()

c. Session框架

  1 #!/usr/bin/env python
  2 #coding:utf-8
  3 
  4 import sys
  5 import math
  6 from bisect import bisect
  7 
  8 
  9 if sys.version_info >= (2, 5):
 10     import hashlib
 11     md5_constructor = hashlib.md5
 12 else:
 13     import md5
 14     md5_constructor = md5.new
 15 
 16 
 17 class HashRing(object):
 18     """一致性哈希"""
 19     
 20     def __init__(self,nodes):
 21         '''初始化
 22         nodes : 初始化的节点,其中包含节点已经节点对应的权重
 23                 默认每一个节点有32个虚拟节点
 24                 对于权重,通过多创建虚拟节点来实现
 25                 如:nodes = [
 26                         {'host':'127.0.0.1:8000','weight':1},
 27                         {'host':'127.0.0.1:8001','weight':2},
 28                         {'host':'127.0.0.1:8002','weight':1},
 29                     ]
 30         '''
 31         
 32         self.ring = dict()
 33         self._sorted_keys = []
 34 
 35         self.total_weight = 0
 36         
 37         self.__generate_circle(nodes)
 38         
 39             
 40             
 41     def __generate_circle(self,nodes):
 42         for node_info in nodes:
 43             self.total_weight += node_info.get('weight',1)
 44             
 45         for node_info in nodes:
 46             weight = node_info.get('weight',1)
 47             node = node_info.get('host',None)
 48                 
 49             virtual_node_count = math.floor((32*len(nodes)*weight) / self.total_weight)
 50             for i in xrange(0,int(virtual_node_count)):
 51                 key = self.gen_key_thirty_two( '%s-%s' % (node, i) )
 52                 if self._sorted_keys.__contains__(key):
 53                     raise Exception('该节点已经存在.')
 54                 self.ring[key] = node
 55                 self._sorted_keys.append(key)
 56             
 57     def add_node(self,node):
 58         ''' 新建节点
 59         node : 要添加的节点,格式为:{'host':'127.0.0.1:8002','weight':1},其中第一个元素表示节点,第二个元素表示该节点的权重。
 60         '''
 61         node = node.get('host',None)
 62         if not node:
 63                 raise Exception('节点的地址不能为空.')
 64                 
 65         weight = node.get('weight',1)
 66         
 67         self.total_weight += weight
 68         nodes_count = len(self._sorted_keys) + 1
 69         
 70         virtual_node_count = math.floor((32 * nodes_count * weight) / self.total_weight)
 71         for i in xrange(0,int(virtual_node_count)):
 72             key = self.gen_key_thirty_two( '%s-%s' % (node, i) )
 73             if self._sorted_keys.__contains__(key):
 74                 raise Exception('该节点已经存在.')
 75             self.ring[key] = node
 76             self._sorted_keys.append(key)
 77         
 78     def remove_node(self,node):
 79         ''' 移除节点
 80         node : 要移除的节点 '127.0.0.1:8000'
 81         '''
 82         for key,value in self.ring.items():
 83             if value == node:
 84                 del self.ring[key]
 85                 self._sorted_keys.remove(key)
 86     
 87     def get_node(self,string_key):
 88         '''获取 string_key 所在的节点'''
 89         pos = self.get_node_pos(string_key)
 90         if pos is None:
 91             return None
 92         return self.ring[ self._sorted_keys[pos]].split(':')
 93     
 94     def get_node_pos(self,string_key):
 95         '''获取 string_key 所在的节点的索引'''
 96         if not self.ring:
 97             return None
 98             
 99         key = self.gen_key_thirty_two(string_key)
100         nodes = self._sorted_keys
101         pos = bisect(nodes, key)
102         return pos
103     
104     def gen_key_thirty_two(self, key):
105         
106         m = md5_constructor()
107         m.update(key)
108         return long(m.hexdigest(), 16)
109         
110     def gen_key_sixteen(self,key):
111         
112         b_key = self.__hash_digest(key)
113         return self.__hash_val(b_key, lambda x: x)
114 
115     def __hash_val(self, b_key, entry_fn):
116         return (( b_key[entry_fn(3)] << 24)|(b_key[entry_fn(2)] << 16)|(b_key[entry_fn(1)] << 8)| b_key[entry_fn(0)] )
117 
118     def __hash_digest(self, key):
119         m = md5_constructor()
120         m.update(key)
121         return map(ord, m.digest())
122 
123 
124 """
125 nodes = [
126     {'host':'127.0.0.1:8000','weight':1},
127     {'host':'127.0.0.1:8001','weight':2},
128     {'host':'127.0.0.1:8002','weight':1},
129 ]
130 
131 ring = HashRing(nodes)
132 result = ring.get_node('98708798709870987098709879087')
133 print result
134 
135 """
一致性哈希
 1 from hashlib import sha1
 2 import os, time
 3 
 4 
 5 create_session_id = lambda: sha1('%s%s' % (os.urandom(16), time.time())).hexdigest()
 6 
 7 
 8 class Session(object):
 9 
10     session_id = "__sessionId__"
11 
12     def __init__(self, request):
13         session_value = request.get_cookie(Session.session_id)
14         if not session_value:
15             self._id = create_session_id()
16         else:
17             self._id = session_value
18         request.set_cookie(Session.session_id, self._id)
19 
20     def __getitem__(self, key):
21         # 根据 self._id ,在一致性哈西中找到其对应的服务器IP
22         # 找到相对应的redis服务器,如: r = redis.StrictRedis(host='localhost', port=6379, db=0)
23         # 使用python redis api 链接
24         # 获取数据,即:
25         # return self._redis.hget(self._id, name)
26 
27     def __setitem__(self, key, value):
28         # 根据 self._id ,在一致性哈西中找到其对应的服务器IP
29         # 使用python redis api 链接
30         # 设置session
31         # self._redis.hset(self._id, name, value)
32 
33 
34     def __delitem__(self, key):
35         # 根据 self._id 找到相对应的redis服务器
36         # 使用python redis api 链接
37         # 删除,即:
38         return self._redis.hdel(self._id, name)
Session

2、自定义模型版定

模型绑定有两个主要功能:

  • 自动生成html表单
  • 用户输入验证

在之前学习的Django中为程序员提供了非常便捷的模型绑定功能,但是在Tornado中,一切需要自己动手!!!

 1 <!DOCTYPE html>
 2 <html>
 3 <head lang="en">
 4     <meta charset="UTF-8">
 5     <title></title>
 6     <link href="{{static_url("commons.css")}}" rel="stylesheet" />
 7 </head>
 8 <body>
 9     <h1>hello</h1>
10     <form action="/index" method="post">
11 
12         <p>hostname: <input type="text" name="host" /> </p>
13         <p>ip: <input type="text" name="ip" /> </p>
14         <p>port: <input type="text" name="port" /> </p>
15         <p>phone: <input type="text" name="phone" /> </p>
16         <input type="submit" />
17     </form>
18 </body>
19 </html>
html
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 #!/usr/bin/env python # -*- coding:utf-8 -*-    import tornado.ioloop import tornado.web from hashlib import sha1 import os, time import re       class MainForm(object):     def __init__(self):         self.host = "(.*)"         self.ip = "^(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}$"         self.port = '(\d+)'         self.phone = '^1[3|4|5|8][0-9]\d{8}$'        def check_valid(self, request):         form_dict = self.__dict__         for key, regular in form_dict.items():             post_value = request.get_argument(key)             # 让提交的数据 和 定义的正则表达式进行匹配             ret = re.match(regular, post_value)             print key,ret,post_value       class MainHandler(tornado.web.RequestHandler):     def get(self):         self.render('index.html')     def post(self*args, **kwargs):         obj = MainForm()         result = obj.check_valid(self)         self.write('ok')          settings = {     'template_path''template',     'static_path''static',     'static_url_prefix''/static/',     'cookie_secret''aiuasdhflashjdfoiuashdfiuh',     'login_url''/login' }    application = tornado.web.Application([     (r"/index", MainHandler), ], **settings)       if __name__ == "__main__":     application.listen(8888)     tornado.ioloop.IOLoop.instance().start()

由于请求的验证时,需要考虑是否可以为空以及正则表达式的复用,所以:

  1 #!/usr/bin/env python
  2 # -*- coding:utf-8 -*-
  3 
  4 import tornado.ioloop
  5 import tornado.web
  6 import re
  7 
  8 
  9 class Field(object):
 10 
 11     def __init__(self, error_msg_dict, required):
 12         self.id_valid = False
 13         self.value = None
 14         self.error = None
 15         self.name = None
 16         self.error_msg = error_msg_dict
 17         self.required = required
 18 
 19     def match(self, name, value):
 20         self.name = name
 21 
 22         if not self.required:
 23             self.id_valid = True
 24             self.value = value
 25         else:
 26             if not value:
 27                 if self.error_msg.get('required', None):
 28                     self.error = self.error_msg['required']
 29                 else:
 30                     self.error = "%s is required" % name
 31             else:
 32                 ret = re.match(self.REGULAR, value)
 33                 if ret:
 34                     self.id_valid = True
 35                     self.value = ret.group()
 36                 else:
 37                     if self.error_msg.get('valid', None):
 38                         self.error = self.error_msg['valid']
 39                     else:
 40                         self.error = "%s is invalid" % name
 41 
 42 
 43 class IPField(Field):
 44     REGULAR = "^(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}$"
 45 
 46     def __init__(self, error_msg_dict=None, required=True):
 47 
 48         error_msg = {}  # {'required': 'IP不能为空', 'valid': 'IP格式错误'}
 49         if error_msg_dict:
 50             error_msg.update(error_msg_dict)
 51 
 52         super(IPField, self).__init__(error_msg_dict=error_msg, required=required)
 53 
 54 
 55 class IntegerField(Field):
 56     REGULAR = "^\d+$"
 57 
 58     def __init__(self, error_msg_dict=None, required=True):
 59         error_msg = {'required': '数字不能为空', 'valid': '数字格式错误'}
 60         if error_msg_dict:
 61             error_msg.update(error_msg_dict)
 62 
 63         super(IntegerField, self).__init__(error_msg_dict=error_msg, required=required)
 64 
 65 
 66 class CheckBoxField(Field):
 67 
 68     def __init__(self, error_msg_dict=None, required=True):
 69         error_msg = {}  # {'required': 'IP不能为空', 'valid': 'IP格式错误'}
 70         if error_msg_dict:
 71             error_msg.update(error_msg_dict)
 72 
 73         super(CheckBoxField, self).__init__(error_msg_dict=error_msg, required=required)
 74 
 75     def match(self, name, value):
 76         self.name = name
 77 
 78         if not self.required:
 79             self.id_valid = True
 80             self.value = value
 81         else:
 82             if not value:
 83                 if self.error_msg.get('required', None):
 84                     self.error = self.error_msg['required']
 85                 else:
 86                     self.error = "%s is required" % name
 87             else:
 88                 if isinstance(name, list):
 89                     self.id_valid = True
 90                     self.value = value
 91                 else:
 92                     if self.error_msg.get('valid', None):
 93                         self.error = self.error_msg['valid']
 94                     else:
 95                         self.error = "%s is invalid" % name
 96 
 97 
 98 class FileField(Field):
 99     REGULAR = "^(\w+\.pdf)|(\w+\.mp3)|(\w+\.py)$"
100 
101     def __init__(self, error_msg_dict=None, required=True):
102         error_msg = {}  # {'required': '数字不能为空', 'valid': '数字格式错误'}
103         if error_msg_dict:
104             error_msg.update(error_msg_dict)
105 
106         super(FileField, self).__init__(error_msg_dict=error_msg, required=required)
107 
108     def match(self, name, value):
109         self.name = name
110         self.value = []
111         if not self.required:
112             self.id_valid = True
113             self.value = value
114         else:
115             if not value:
116                 if self.error_msg.get('required', None):
117                     self.error = self.error_msg['required']
118                 else:
119                     self.error = "%s is required" % name
120             else:
121                 m = re.compile(self.REGULAR)
122                 if isinstance(value, list):
123                     for file_name in value:
124                         r = m.match(file_name)
125                         if r:
126                             self.value.append(r.group())
127                             self.id_valid = True
128                         else:
129                             self.id_valid = False
130                             if self.error_msg.get('valid', None):
131                                 self.error = self.error_msg['valid']
132                             else:
133                                 self.error = "%s is invalid" % name
134                             break
135                 else:
136                     if self.error_msg.get('valid', None):
137                         self.error = self.error_msg['valid']
138                     else:
139                         self.error = "%s is invalid" % name
140 
141     def save(self, request, upload_path=""):
142 
143         file_metas = request.files[self.name]
144         for meta in file_metas:
145             file_name = meta['filename']
146             with open(file_name,'wb') as up:
147                 up.write(meta['body'])
148 
149 
150 class Form(object):
151 
152     def __init__(self):
153         self.value_dict = {}
154         self.error_dict = {}
155         self.valid_status = True
156 
157     def validate(self, request, depth=10, pre_key=""):
158 
159         self.initialize()
160         self.__valid(self, request, depth, pre_key)
161 
162     def initialize(self):
163         pass
164 
165     def __valid(self, form_obj, request, depth, pre_key):
166         """
167         验证用户表单请求的数据
168         :param form_obj: Form对象(Form派生类的对象)
169         :param request: Http请求上下文(用于从请求中获取用户提交的值)
170         :param depth: 对Form内容的深度的支持
171         :param pre_key: Html中name属性值的前缀(多层Form时,内部递归时设置,无需理会)
172         :return: 是否验证通过,True:验证成功;False:验证失败
173         """
174 
175         depth -= 1
176         if depth < 0:
177             return None
178         form_field_dict = form_obj.__dict__
179         for key, field_obj in form_field_dict.items():
180             print key,field_obj
181             if isinstance(field_obj, Form) or isinstance(field_obj, Field):
182                 if isinstance(field_obj, Form):
183                     # 获取以key开头的所有的值,以参数的形式传至
184                     self.__valid(field_obj, request, depth, key)
185                     continue
186                 if pre_key:
187                     key = "%s.%s" % (pre_key, key)
188 
189                 if isinstance(field_obj, CheckBoxField):
190                     post_value = request.get_arguments(key, None)
191                 elif isinstance(field_obj, FileField):
192                     post_value = []
193                     file_list = request.request.files.get(key, None)
194                     for file_item in file_list:
195                         post_value.append(file_item['filename'])
196                 else:
197                     post_value = request.get_argument(key, None)
198 
199                 print post_value
200                 # 让提交的数据 和 定义的正则表达式进行匹配
201                 field_obj.match(key, post_value)
202                 if field_obj.id_valid:
203                     self.value_dict[key] = field_obj.value
204                 else:
205                     self.error_dict[key] = field_obj.error
206                     self.valid_status = False
207 
208 
209 class ListForm(object):
210     def __init__(self, form_type):
211         self.form_type = form_type
212         self.valid_status = True
213         self.value_dict = {}
214         self.error_dict = {}
215 
216     def validate(self, request):
217         name_list = request.request.arguments.keys() + request.request.files.keys()
218         index = 0
219         flag = False
220         while True:
221             pre_key = "[%d]" % index
222             for name in name_list:
223                 if name.startswith(pre_key):
224                     flag = True
225                     break
226             if flag:
227                 form_obj = self.form_type()
228                 form_obj.validate(request, depth=10, pre_key="[%d]" % index)
229                 if form_obj.valid_status:
230                     self.value_dict[index] = form_obj.value_dict
231                 else:
232                     self.error_dict[index] = form_obj.error_dict
233                     self.valid_status = False
234             else:
235                 break
236 
237             index += 1
238             flag = False
239 
240 
241 class MainForm(Form):
242 
243     def __init__(self):
244         # self.ip = IPField(required=True)
245         # self.port = IntegerField(required=True)
246         # self.new_ip = IPField(required=True)
247         # self.second = SecondForm()
248         self.fff = FileField(required=True)
249         super(MainForm, self).__init__()
250 
251 #
252 # class SecondForm(Form):
253 #
254 #     def __init__(self):
255 #         self.ip = IPField(required=True)
256 #         self.new_ip = IPField(required=True)
257 #
258 #         super(SecondForm, self).__init__()
259 
260 
261 class MainHandler(tornado.web.RequestHandler):
262     def get(self):
263         self.render('index.html')
264     def post(self, *args, **kwargs):
265         # for i in  dir(self.request):
266         #     print i
267         # print self.request.arguments
268         # print self.request.files
269         # print self.request.query
270         # name_list = self.request.arguments.keys() + self.request.files.keys()
271         # print name_list
272 
273         # list_form = ListForm(MainForm)
274         # list_form.validate(self)
275         #
276         # print list_form.valid_status
277         # print list_form.value_dict
278         # print list_form.error_dict
279 
280         # obj = MainForm()
281         # obj.validate(self)
282         #
283         # print "验证结果:", obj.valid_status
284         # print "符合验证结果:", obj.value_dict
285         # print "错误信息:"
286         # for key, item in obj.error_dict.items():
287         #     print key,item
288         # print self.get_arguments('favor'),type(self.get_arguments('favor'))
289         # print self.get_argument('favor'),type(self.get_argument('favor'))
290         # print type(self.get_argument('fff')),self.get_argument('fff')
291         # print self.request.files
292         # obj = MainForm()
293         # obj.validate(self)
294         # print obj.valid_status
295         # print obj.value_dict
296         # print obj.error_dict
297         # print self.request,type(self.request)
298         # obj.fff.save(self.request)
299         # from tornado.httputil import HTTPServerRequest
300         # name_list = self.request.arguments.keys() + self.request.files.keys()
301         # print name_list
302         # print self.request.files,type(self.request.files)
303         # print len(self.request.files.get('fff'))
304         
305         # obj = MainForm()
306         # obj.validate(self)
307         # print obj.valid_status
308         # print obj.value_dict
309         # print obj.error_dict
310         # obj.fff.save(self.request)
311         self.write('ok')
312 
313 
314 
315 settings = {
316     'template_path': 'template',
317     'static_path': 'static',
318     'static_url_prefix': '/static/',
319     'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh',
320     'login_url': '/login'
321 }
322 
323 application = tornado.web.Application([
324     (r"/index", MainHandler),
325 ], **settings)
326 
327 
328 if __name__ == "__main__":
329     application.listen(8888)
330     tornado.ioloop.IOLoop.instance().start()
Form验证框架
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