• 【python之路42】web框架们的具体用法


    Python的WEB框架

    (一)、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。

    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、makojinja2cheetah
    • 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:
    • 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,
      }
      View Code

    框架的基本使用:

    #!/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

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

    2、动态路由

    @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

    @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

    #!/usr/bin/env python
    # -*- coding:utf-8 -*-
    from bottle import template, Bottle
    
    app01 = Bottle()
    
    @app01.route('/hello/', method='GET')
    def index():
        return template('<b>App01</b>!')
    app01.py
    #!/usr/bin/env python
    # -*- coding:utf-8 -*-
    from bottle import template, Bottle
    
    app02 = Bottle()
    
    
    @app02.route('/hello/', method='GET')
    def index():
        return template('<b>App02</b>!')
    app02.py
    #!/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、makojinja2cheetah等,以内置模板系统为例:

    <!DOCTYPE html>
    <html>
    <head lang="en">
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
        <h1>{{name}}</h1>
    </body>
    </html>
    hello_template.tpl
    #!/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
    • <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)

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

    rebase(name, **variables)

    <html>
    <head>
      <title>{{title or 'No title'}}</title>
    </head>
    <body>
      {{!base}}
    </body>
    </html>
    base.tpl
    # 导入母版
     
    % rebase('base.tpl', title='Page Title')
    <p>Page Content ...</p>

    defined(name)

    # 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)

    # 获取某个变量的值,不存在时可设置默认值

    setdefault(name, default)

    # 如果变量不存在时,为变量设置默认值

    扩展:自定义函数

    <!DOCTYPE html>
    <html>
    <head lang="en">
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
        <h1>自定义函数</h1>
        {{ wupeiqi() }}
    
    </body>
    </html>
    hello_template.tpl
    #!/usr/bin/env python
    # -*- coding:utf-8 -*-
    from bottle import template, Bottle,SimpleTemplate
    root = Bottle()
    
    
    def custom():
        return '123123'
    
    
    @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.html', name='alex', wupeiqi=custom)
    
    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:

    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:

    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:

    from bottle import route, request
    
    @route('/login')
    def login():
        return '''
            <form action="/login" method="post">
                Username: <input name="username" type="text" />
                Password: <input name="password" type="password" />
                <input value="Login" type="submit" />
            </form>
        '''
    
    @route('/login', method='POST')
    def do_login():
        username = request.forms.get('username')
        password = request.forms.get('password')
        if check_login(username, password):
            return "<p>Your login information was correct.</p>"
        else:
            return "<p>Login failed.</p>"
    基本Form请求
    <form action="/upload" method="post" enctype="multipart/form-data">
      Category:      <input type="text" name="category" />
      Select a file: <input type="file" name="upload" />
      <input type="submit" value="Start upload" />
    </form>
    
    
    @route('/upload', method='POST')
    def do_upload():
        category   = request.forms.get('category')
        upload     = request.files.get('upload')
        name, ext = os.path.splitext(upload.filename)
        if ext not in ('.png','.jpg','.jpeg'):
            return 'File extension not allowed.'
    
        save_path = get_save_path_for_category(category)
        upload.save(save_path) # appends upload.filename automatically
        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:

    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,
    }
    WSGI

    使用时,只需在主app执行run方法时指定参数即可:

    #!/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:

    # 如果使用Tornado的服务,则需要首先安装tornado才能使用
    
    class TornadoServer(ServerAdapter):
        """ The super hyped asynchronous server by facebook. Untested. """
        def run(self, handler): # pragma: no cover
            # 导入Tornado相关模块
            import tornado.wsgi, tornado.httpserver, tornado.ioloop
            container = tornado.wsgi.WSGIContainer(handler)
            server = tornado.httpserver.HTTPServer(container)
            server.listen(port=self.port,address=self.host)
            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

     (二)、Flask框架

    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

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

    一、第一次

    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:

    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:

    <!DOCTYPE html>
    <html>
    <head lang="en">
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
        <h1>自定义函数</h1>
        {{ww()|safe}}
    
    </body>
    </html>
    index.html
    #!/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:

    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
    @app.route('/login', methods=['POST', 'GET'])
    def login():
        error = None
        if request.method == 'POST':
            if valid_login(request.form['username'],
                           request.form['password']):
                return log_the_user_in(request.form['username'])
            else:
                error = 'Invalid username/password'
        # the code below is executed if the request method
        # was GET or the credentials were invalid
        return render_template('login.html', error=error)
    表单处理Demo
    from flask import request
    from werkzeug import secure_filename
    
    @app.route('/upload', methods=['GET', 'POST'])
    def upload_file():
        if request.method == 'POST':
            f = request.files['the_file']
            f.save('/var/www/uploads/' + secure_filename(f.filename))
        ...
    上传文件Demo
    from flask import request
    
    @app.route('/setcookie/')
    def index():
        username = request.cookies.get('username')
        # use cookies.get(key) instead of cookies[key] to not get a
        # KeyError if the cookie is missing.
    
    
    
    
    from flask import make_response
    
    @app.route('/getcookie')
    def index():
        resp = make_response(render_template(...))
        resp.set_cookie('username', 'the username')
        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

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

    b.模板引擎

    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

    #!/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

    from flask import Flask, abort, render_template
    app = Flask(__name__)
    
    @app.route('/e1/', methods=['GET', 'POST'])
    def index():
        abort(404, 'Nothing')
    app.run()
    指定URL,简单错误
    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

    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)
    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

    <!DOCTYPE html>
    <html>
    <head lang="en">
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
        {% with messages = get_flashed_messages() %}
            {% if messages %}
            <ul class=flashes>
                {% for message in messages %}
                <li>{{ message }}</li>
                {% endfor %}
            </ul>
            {% endif %}
        {% endwith %}
    </body>
    </html>
    index.html
    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():
        v = request.args.get('p')
        flash(v)
        return 'ok'
     
    if __name__ == "__main__":
        app.run()

    5.中间件

    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():
        v = 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/

    (三)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。)

    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

    #!/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

    #!/usr/bin/env python
    # -*- coding:utf-8 -*-
    #!/usr/bin/env python
    # -*- coding:utf-8 -*-
    
    import tornado.ioloop
    import tornado.web
    from tornado import httpclient
    from tornado.web import asynchronous
    from tornado import gen
    
    import uimodules as md
    import uimethods as mt
    
    class MainHandler(tornado.web.RequestHandler):
            @asynchronous
            @gen.coroutine
            def get(self):
                print 'start get '
                http = httpclient.AsyncHTTPClient()
                http.fetch("http://127.0.0.1:8008/post/", self.callback)
                self.write('end')
    
            def callback(self, response):
                print response.body
    
    settings = {
        'template_path': 'template',
        'static_path': 'static',
        'static_url_prefix': '/static/',
        'ui_methods': mt,
        'ui_modules': md,
    }
    
    application = tornado.web.Application([
        (r"/index", MainHandler),
    ], **settings)
    
    
    if __name__ == "__main__":
        application.listen(8009)
        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。

    #!/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 {%  %} 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。

    <!DOCTYPE html>
    <html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
        <title>老男孩</title>
        <link href="{{static_url("css/common.css")}}" rel="stylesheet" />
        {% block CSS %}{% end %}
    </head>
    <body>
    
        <div class="pg-header">
    
        </div>
        
        {% block RenderBody %}{% end %}
       
        <script src="{{static_url("js/jquery-1.8.2.min.js")}}"></script>
        
        {% block JavaScript %}{% end %}
    </body>
    </html>
    layout.html
    {% extends 'layout.html'%}
    {% block CSS %}
        <link href="{{static_url("css/index.css")}}" rel="stylesheet" />
    {% end %}
    
    {% block RenderBody %}
        <h1>Index</h1>
    
        <ul>
        {%  for item in li %}
            <li>{{item}}</li>
        {% end %}
        </ul>
    
    {% end %}
    
    {% block JavaScript %}
        
    {% end %}
    index.html
    #!/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

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

    2、注册

    #!/usr/bin/env python
    # -*- coding:utf-8 -*-
    #!/usr/bin/env python
    # -*- coding:utf-8 -*-
    
    import tornado.ioloop
    import tornado.web
    from tornado.escape import linkify
    import uimodules as md
    import uimethods as mt
    
    class MainHandler(tornado.web.RequestHandler):
        def get(self):
            self.render('index.html')
    
    settings = {
        'template_path': 'template',
        'static_path': 'static',
        'static_url_prefix': '/static/',
        'ui_methods': mt,
        'ui_modules': md,
    }
    
    application = tornado.web.Application([
        (r"/index", MainHandler),
    ], **settings)
    
    
    if __name__ == "__main__":
        application.listen(8009)
        tornado.ioloop.IOLoop.instance().start()
    main.py

    3、使用

    <!DOCTYPE html>
    <html>
    <head lang="en">
        <meta charset="UTF-8">
        <title></title>
        <link href="{{static_url("commons.css")}}" rel="stylesheet" />
    </head>
    <body>
        <h1>hello</h1>
        {% module custom(123) %}
        {{ tab() }}
    </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。

    #!/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',
        'static_path': 'static',
        'static_url_prefix': '/static/',
    }
     
    application = tornado.web.Application([
        (r"/index", MainHandler),
    ], **settings)
     
     
    if __name__ == "__main__":
        application.listen(80)
        tornado.ioloop.IOLoop.instance().start()
    main.py
    <!DOCTYPE html>
    <html>
    <head lang="en">
        <meta charset="UTF-8">
        <title></title>
        <link href="{{static_url("commons.css")}}" rel="stylesheet" />
    </head>
    <body>
        <h1>hello</h1>
    </body>
    </html>
    index.html
    def get_content_version(cls, abspath):
            """Returns a version string for the resource at the given path.
    
            This class method may be overridden by subclasses.  The
            default implementation is a hash of the file's contents.
    
            .. versionadded:: 3.1
            """
            data = cls.get_content(abspath)
            hasher = hashlib.md5()
            if isinstance(data, bytes):
                hasher.update(data)
            else:
                for chunk in data:
                    hasher.update(chunk)
            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)

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

    class MainHandler(tornado.web.RequestHandler):
        def get(self):
            if not self.get_cookie("mycookie"):
                self.set_cookie("mycookie", "myvalue")
                self.write("Your cookie was not set yet!")
            else:
                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:

    class MainHandler(tornado.web.RequestHandler):
        def get(self):
            if not self.get_secure_cookie("mycookie"):
                self.set_secure_cookie("mycookie", "myvalue")
                self.write("Your cookie was not set yet!")
            else:
                self.write("Your cookie was set!")
                 
    application = tornado.web.Application([
        (r"/", MainHandler),
    ], cookie_secret="61oETzKXQAGaYdkL5gEmGeJJFuYh7EQnp2XdTP1o/Vo=")
    Code
    def _create_signature_v1(secret, *parts):
        hash = hmac.new(utf8(secret), digestmod=hashlib.sha1)
        for part in parts:
            hash.update(utf8(part))
        return utf8(hash.hexdigest())
    
    
    def _create_signature_v2(secret, s):
        hash = hmac.new(utf8(secret), digestmod=hashlib.sha256)
        hash.update(utf8(s))
        return utf8(hash.hexdigest())
    内部算法
    def create_signed_value(secret, name, value, version=None, clock=None,
                            key_version=None):
        if version is None:
            version = DEFAULT_SIGNED_VALUE_VERSION
        if clock is None:
            clock = time.time
    
        timestamp = utf8(str(int(clock())))
        value = base64.b64encode(utf8(value))
        if version == 1:
            signature = _create_signature_v1(secret, name, value, timestamp)
            value = b"|".join([value, timestamp, signature])
            return value
        elif version == 2:
            # The v2 format consists of a version number and a series of
            # length-prefixed fields "%d:%s", the last of which is a
            # signature, all separated by pipes.  All numbers are in
            # decimal format with no leading zeros.  The signature is an
            # HMAC-SHA256 of the whole string up to that point, including
            # the final pipe.
            #
            # The fields are:
            # - format version (i.e. 2; no length prefix)
            # - key version (integer, default is 0)
            # - timestamp (integer seconds since epoch)
            # - name (not encoded; assumed to be ~alphanumeric)
            # - value (base64-encoded)
            # - signature (hex-encoded; no length prefix)
            def format_field(s):
                return utf8("%d:" % len(s)) + utf8(s)
            to_sign = b"|".join([
                b"2",
                format_field(str(key_version or 0)),
                format_field(timestamp),
                format_field(name),
                format_field(value),
                b''])
    
            if isinstance(secret, dict):
                assert key_version is not None, 'Key version must be set when sign key dict is used'
                assert version >= 2, 'Version must be at least 2 for key version support'
                secret = secret[key_version]
    
            signature = _create_signature_v2(secret, to_sign)
            return to_sign + signature
        else:
            raise ValueError("Unsupported version %d" % version)
    内部算法-加密
    def _decode_signed_value_v1(secret, name, value, max_age_days, clock):
        parts = utf8(value).split(b"|")
        if len(parts) != 3:
            return None
        signature = _create_signature_v1(secret, name, parts[0], parts[1])
        if not _time_independent_equals(parts[2], signature):
            gen_log.warning("Invalid cookie signature %r", value)
            return None
        timestamp = int(parts[1])
        if timestamp < clock() - max_age_days * 86400:
            gen_log.warning("Expired cookie %r", value)
            return None
        if timestamp > clock() + 31 * 86400:
            # _cookie_signature does not hash a delimiter between the
            # parts of the cookie, so an attacker could transfer trailing
            # digits from the payload to the timestamp without altering the
            # signature.  For backwards compatibility, sanity-check timestamp
            # here instead of modifying _cookie_signature.
            gen_log.warning("Cookie timestamp in future; possible tampering %r",
                            value)
            return None
        if parts[1].startswith(b"0"):
            gen_log.warning("Tampered cookie %r", value)
            return None
        try:
            return base64.b64decode(parts[0])
        except Exception:
            return None
    
    
    def _decode_fields_v2(value):
        def _consume_field(s):
            length, _, rest = s.partition(b':')
            n = int(length)
            field_value = rest[:n]
            # In python 3, indexing bytes returns small integers; we must
            # use a slice to get a byte string as in python 2.
            if rest[n:n + 1] != b'|':
                raise ValueError("malformed v2 signed value field")
            rest = rest[n + 1:]
            return field_value, rest
    
        rest = value[2:]  # remove version number
        key_version, rest = _consume_field(rest)
        timestamp, rest = _consume_field(rest)
        name_field, rest = _consume_field(rest)
        value_field, passed_sig = _consume_field(rest)
        return int(key_version), timestamp, name_field, value_field, passed_sig
    
    
    def _decode_signed_value_v2(secret, name, value, max_age_days, clock):
        try:
            key_version, timestamp, name_field, value_field, passed_sig = _decode_fields_v2(value)
        except ValueError:
            return None
        signed_string = value[:-len(passed_sig)]
    
        if isinstance(secret, dict):
            try:
                secret = secret[key_version]
            except KeyError:
                return None
    
        expected_sig = _create_signature_v2(secret, signed_string)
        if not _time_independent_equals(passed_sig, expected_sig):
            return None
        if name_field != utf8(name):
            return None
        timestamp = int(timestamp)
        if timestamp < clock() - max_age_days * 86400:
            # The signature has expired.
            return None
        try:
            return base64.b64decode(value_field)
        except Exception:
            return None
    
    
    def get_signature_key_version(value):
        value = utf8(value)
        version = _get_version(value)
        if version < 2:
            return None
        try:
            key_version, _, _, _, _ = _decode_fields_v2(value)
        except ValueError:
            return None
    
        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。

    #!/usr/bin/env python
    # -*- coding:utf-8 -*-
     
    import tornado.ioloop
    import tornado.web
     
     
    class MainHandler(tornado.web.RequestHandler):
     
        def get(self):
            login_user = self.get_secure_cookie("login_user", None)
            if login_user:
                self.write(login_user)
            else:
                self.redirect('/login')
     
     
    class LoginHandler(tornado.web.RequestHandler):
        def get(self):
            self.current_user()
     
            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.set_secure_cookie('login_user', '武沛齐')
                self.redirect('/')
            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'
    }
     
    application = tornado.web.Application([
        (r"/index", MainHandler),
        (r"/login", LoginHandler),
    ], **settings)
     
     
    if __name__ == "__main__":
        application.listen(8888)
        tornado.ioloop.IOLoop.instance().start()
    Demo-基于cookie进行用户验证
    #!/usr/bin/env python
    # -*- coding:utf-8 -*-
     
    import tornado.ioloop
    import tornado.web
     
    class BaseHandler(tornado.web.RequestHandler):
     
        def get_current_user(self):
            return self.get_secure_cookie("login_user")
     
    class MainHandler(BaseHandler):
     
        @tornado.web.authenticated
        def get(self):
            login_user = self.current_user
            self.write(login_user)
     
     
     
    class LoginHandler(tornado.web.RequestHandler):
        def get(self):
            self.current_user()
     
            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.set_secure_cookie('login_user', '武沛齐')
                self.redirect('/')
            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()
    Demo-Toando内部提供基于cookie进行用户验证

    4、Ajax上传文件

    <!DOCTYPE html>
    <html>
    <head lang="en">
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
        <input type="file" id="img" />
        <input type="button" onclick="UploadFile();" />
        <script>
            function UploadFile(){
                var fileObj = document.getElementById("img").files[0];
    
                var form = new FormData();
                form.append("k1", "v1");
                form.append("fff", fileObj);
    
                var xhr = new XMLHttpRequest();
                xhr.open("post", '/index', true);
                xhr.send(form);
            }
        </script>
    </body>
    </html>
    Html
    #!/usr/bin/env python
    # -*- coding:utf-8 -*-
    #!/usr/bin/env python
    # -*- coding:utf-8 -*-
    
    import tornado.ioloop
    import tornado.web
    
    
    class MainHandler(tornado.web.RequestHandler):
        def get(self):
    
            self.render('index.html')
    
        def post(self, *args, **kwargs):
            file_metas = self.request.files["fff"]
            # print(file_metas)
            for meta in file_metas:
                file_name = meta['filename']
                with open(file_name,'wb') as up:
                    up.write(meta['body'])
    
    settings = {
        'template_path': 'template',
    }
    
    application = tornado.web.Application([
        (r"/index", MainHandler),
    ], **settings)
    
    
    if __name__ == "__main__":
        application.listen(8000)
        tornado.ioloop.IOLoop.instance().start()
    Python
    var fileObj = $("#img")[0].files[0];
    var form = new FormData();
    form.append("k1", "v1");
    form.append("fff", fileObj);
    
    $.ajax({
        type:'POST',
        url: '/index',
        data: form,
        processData: false,  // tell jQuery not to process the data
        contentType: false,  // tell jQuery not to set contentType
        success: function(arg){
            console.log(arg);
        }
    })
    jQuery Ajax Upload

    五、扩展功能

    1、自定义Session

    a.知识储备

    #!/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']
    View Code

    b.session实现机制

    #!/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()
    View Code

    c. Session框架

    #!/usr/bin/env python
    #coding:utf-8
    
    import sys
    import math
    from bisect import bisect
    
    
    if sys.version_info >= (2, 5):
        import hashlib
        md5_constructor = hashlib.md5
    else:
        import md5
        md5_constructor = md5.new
    
    
    class HashRing(object):
        """一致性哈希"""
        
        def __init__(self,nodes):
            '''初始化
            nodes : 初始化的节点,其中包含节点已经节点对应的权重
                    默认每一个节点有32个虚拟节点
                    对于权重,通过多创建虚拟节点来实现
                    如:nodes = [
                            {'host':'127.0.0.1:8000','weight':1},
                            {'host':'127.0.0.1:8001','weight':2},
                            {'host':'127.0.0.1:8002','weight':1},
                        ]
            '''
            
            self.ring = dict()
            self._sorted_keys = []
    
            self.total_weight = 0
            
            self.__generate_circle(nodes)
            
                
                
        def __generate_circle(self,nodes):
            for node_info in nodes:
                self.total_weight += node_info.get('weight',1)
                
            for node_info in nodes:
                weight = node_info.get('weight',1)
                node = node_info.get('host',None)
                    
                virtual_node_count = math.floor((32*len(nodes)*weight) / self.total_weight)
                for i in xrange(0,int(virtual_node_count)):
                    key = self.gen_key_thirty_two( '%s-%s' % (node, i) )
                    if self._sorted_keys.__contains__(key):
                        raise Exception('该节点已经存在.')
                    self.ring[key] = node
                    self._sorted_keys.append(key)
                
        def add_node(self,node):
            ''' 新建节点
            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。
            '''
            node = node.get('host',None)
            if not node:
                    raise Exception('节点的地址不能为空.')
                    
            weight = node.get('weight',1)
            
            self.total_weight += weight
            nodes_count = len(self._sorted_keys) + 1
            
            virtual_node_count = math.floor((32 * nodes_count * weight) / self.total_weight)
            for i in xrange(0,int(virtual_node_count)):
                key = self.gen_key_thirty_two( '%s-%s' % (node, i) )
                if self._sorted_keys.__contains__(key):
                    raise Exception('该节点已经存在.')
                self.ring[key] = node
                self._sorted_keys.append(key)
            
        def remove_node(self,node):
            ''' 移除节点
            node : 要移除的节点 '127.0.0.1:8000'
            '''
            for key,value in self.ring.items():
                if value == node:
                    del self.ring[key]
                    self._sorted_keys.remove(key)
        
        def get_node(self,string_key):
            '''获取 string_key 所在的节点'''
            pos = self.get_node_pos(string_key)
            if pos is None:
                return None
            return self.ring[ self._sorted_keys[pos]].split(':')
        
        def get_node_pos(self,string_key):
            '''获取 string_key 所在的节点的索引'''
            if not self.ring:
                return None
                
            key = self.gen_key_thirty_two(string_key)
            nodes = self._sorted_keys
            pos = bisect(nodes, key)
            return pos
        
        def gen_key_thirty_two(self, key):
            
            m = md5_constructor()
            m.update(key)
            return long(m.hexdigest(), 16)
            
        def gen_key_sixteen(self,key):
            
            b_key = self.__hash_digest(key)
            return self.__hash_val(b_key, lambda x: x)
    
        def __hash_val(self, b_key, entry_fn):
            return (( b_key[entry_fn(3)] << 24)|(b_key[entry_fn(2)] << 16)|(b_key[entry_fn(1)] << 8)| b_key[entry_fn(0)] )
    
        def __hash_digest(self, key):
            m = md5_constructor()
            m.update(key)
            return map(ord, m.digest())
    
    
    """
    nodes = [
        {'host':'127.0.0.1:8000','weight':1},
        {'host':'127.0.0.1:8001','weight':2},
        {'host':'127.0.0.1:8002','weight':1},
    ]
    
    ring = HashRing(nodes)
    result = ring.get_node('98708798709870987098709879087')
    print result
    
    """
    一致性哈希
    from hashlib import sha1
    import os, time
    
    
    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):
            # 根据 self._id ,在一致性哈西中找到其对应的服务器IP
            # 找到相对应的redis服务器,如: r = redis.StrictRedis(host='localhost', port=6379, db=0)
            # 使用python redis api 链接
            # 获取数据,即:
            # return self._redis.hget(self._id, name)
    
        def __setitem__(self, key, value):
            # 根据 self._id ,在一致性哈西中找到其对应的服务器IP
            # 使用python redis api 链接
            # 设置session
            # self._redis.hset(self._id, name, value)
    
    
        def __delitem__(self, key):
            # 根据 self._id 找到相对应的redis服务器
            # 使用python redis api 链接
            # 删除,即:
            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!!!

    <!DOCTYPE html>
    <html>
    <head lang="en">
        <meta charset="UTF-8">
        <title></title>
        <link href="{{static_url("commons.css")}}" rel="stylesheet" />
    </head>
    <body>
        <h1>hello</h1>
        <form action="/index" method="post">
    
            <p>hostname: <input type="text" name="host" /> </p>
            <p>ip: <input type="text" name="ip" /> </p>
            <p>port: <input type="text" name="port" /> </p>
            <p>phone: <input type="text" name="phone" /> </p>
            <input type="submit" />
        </form>
    </body>
    </html>
    html
    #!/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:

    #!/usr/bin/env python
    # -*- coding:utf-8 -*-
    
    import tornado.ioloop
    import tornado.web
    import re
    
    
    class Field(object):
    
        def __init__(self, error_msg_dict, required):
            self.id_valid = False
            self.value = None
            self.error = None
            self.name = None
            self.error_msg = error_msg_dict
            self.required = required
    
        def match(self, name, value):
            self.name = name
    
            if not self.required:
                self.id_valid = True
                self.value = value
            else:
                if not value:
                    if self.error_msg.get('required', None):
                        self.error = self.error_msg['required']
                    else:
                        self.error = "%s is required" % name
                else:
                    ret = re.match(self.REGULAR, value)
                    if ret:
                        self.id_valid = True
                        self.value = ret.group()
                    else:
                        if self.error_msg.get('valid', None):
                            self.error = self.error_msg['valid']
                        else:
                            self.error = "%s is invalid" % name
    
    
    class IPField(Field):
        REGULAR = "^(25[0-5]|2[0-4]d|[0-1]?d?d)(.(25[0-5]|2[0-4]d|[0-1]?d?d)){3}$"
    
        def __init__(self, error_msg_dict=None, required=True):
    
            error_msg = {}  # {'required': 'IP不能为空', 'valid': 'IP格式错误'}
            if error_msg_dict:
                error_msg.update(error_msg_dict)
    
            super(IPField, self).__init__(error_msg_dict=error_msg, required=required)
    
    
    class IntegerField(Field):
        REGULAR = "^d+$"
    
        def __init__(self, error_msg_dict=None, required=True):
            error_msg = {'required': '数字不能为空', 'valid': '数字格式错误'}
            if error_msg_dict:
                error_msg.update(error_msg_dict)
    
            super(IntegerField, self).__init__(error_msg_dict=error_msg, required=required)
    
    
    class CheckBoxField(Field):
    
        def __init__(self, error_msg_dict=None, required=True):
            error_msg = {}  # {'required': 'IP不能为空', 'valid': 'IP格式错误'}
            if error_msg_dict:
                error_msg.update(error_msg_dict)
    
            super(CheckBoxField, self).__init__(error_msg_dict=error_msg, required=required)
    
        def match(self, name, value):
            self.name = name
    
            if not self.required:
                self.id_valid = True
                self.value = value
            else:
                if not value:
                    if self.error_msg.get('required', None):
                        self.error = self.error_msg['required']
                    else:
                        self.error = "%s is required" % name
                else:
                    if isinstance(name, list):
                        self.id_valid = True
                        self.value = value
                    else:
                        if self.error_msg.get('valid', None):
                            self.error = self.error_msg['valid']
                        else:
                            self.error = "%s is invalid" % name
    
    
    class FileField(Field):
        REGULAR = "^(w+.pdf)|(w+.mp3)|(w+.py)$"
    
        def __init__(self, error_msg_dict=None, required=True):
            error_msg = {}  # {'required': '数字不能为空', 'valid': '数字格式错误'}
            if error_msg_dict:
                error_msg.update(error_msg_dict)
    
            super(FileField, self).__init__(error_msg_dict=error_msg, required=required)
    
        def match(self, name, value):
            self.name = name
            self.value = []
            if not self.required:
                self.id_valid = True
                self.value = value
            else:
                if not value:
                    if self.error_msg.get('required', None):
                        self.error = self.error_msg['required']
                    else:
                        self.error = "%s is required" % name
                else:
                    m = re.compile(self.REGULAR)
                    if isinstance(value, list):
                        for file_name in value:
                            r = m.match(file_name)
                            if r:
                                self.value.append(r.group())
                                self.id_valid = True
                            else:
                                self.id_valid = False
                                if self.error_msg.get('valid', None):
                                    self.error = self.error_msg['valid']
                                else:
                                    self.error = "%s is invalid" % name
                                break
                    else:
                        if self.error_msg.get('valid', None):
                            self.error = self.error_msg['valid']
                        else:
                            self.error = "%s is invalid" % name
    
        def save(self, request, upload_path=""):
    
            file_metas = request.files[self.name]
            for meta in file_metas:
                file_name = meta['filename']
                with open(file_name,'wb') as up:
                    up.write(meta['body'])
    
    
    class Form(object):
    
        def __init__(self):
            self.value_dict = {}
            self.error_dict = {}
            self.valid_status = True
    
        def validate(self, request, depth=10, pre_key=""):
    
            self.initialize()
            self.__valid(self, request, depth, pre_key)
    
        def initialize(self):
            pass
    
        def __valid(self, form_obj, request, depth, pre_key):
            """
            验证用户表单请求的数据
            :param form_obj: Form对象(Form派生类的对象)
            :param request: Http请求上下文(用于从请求中获取用户提交的值)
            :param depth: 对Form内容的深度的支持
            :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)
            :return: 是否验证通过,True:验证成功;False:验证失败
            """
    
            depth -= 1
            if depth < 0:
                return None
            form_field_dict = form_obj.__dict__
            for key, field_obj in form_field_dict.items():
                print key,field_obj
                if isinstance(field_obj, Form) or isinstance(field_obj, Field):
                    if isinstance(field_obj, Form):
                        # 获取以key开头的所有的值,以参数的形式传至
                        self.__valid(field_obj, request, depth, key)
                        continue
                    if pre_key:
                        key = "%s.%s" % (pre_key, key)
    
                    if isinstance(field_obj, CheckBoxField):
                        post_value = request.get_arguments(key, None)
                    elif isinstance(field_obj, FileField):
                        post_value = []
                        file_list = request.request.files.get(key, None)
                        for file_item in file_list:
                            post_value.append(file_item['filename'])
                    else:
                        post_value = request.get_argument(key, None)
    
                    print post_value
                    # 让提交的数据 和 定义的正则表达式进行匹配
                    field_obj.match(key, post_value)
                    if field_obj.id_valid:
                        self.value_dict[key] = field_obj.value
                    else:
                        self.error_dict[key] = field_obj.error
                        self.valid_status = False
    
    
    class ListForm(object):
        def __init__(self, form_type):
            self.form_type = form_type
            self.valid_status = True
            self.value_dict = {}
            self.error_dict = {}
    
        def validate(self, request):
            name_list = request.request.arguments.keys() + request.request.files.keys()
            index = 0
            flag = False
            while True:
                pre_key = "[%d]" % index
                for name in name_list:
                    if name.startswith(pre_key):
                        flag = True
                        break
                if flag:
                    form_obj = self.form_type()
                    form_obj.validate(request, depth=10, pre_key="[%d]" % index)
                    if form_obj.valid_status:
                        self.value_dict[index] = form_obj.value_dict
                    else:
                        self.error_dict[index] = form_obj.error_dict
                        self.valid_status = False
                else:
                    break
    
                index += 1
                flag = False
    
    
    class MainForm(Form):
    
        def __init__(self):
            # self.ip = IPField(required=True)
            # self.port = IntegerField(required=True)
            # self.new_ip = IPField(required=True)
            # self.second = SecondForm()
            self.fff = FileField(required=True)
            super(MainForm, self).__init__()
    
    #
    # class SecondForm(Form):
    #
    #     def __init__(self):
    #         self.ip = IPField(required=True)
    #         self.new_ip = IPField(required=True)
    #
    #         super(SecondForm, self).__init__()
    
    
    class MainHandler(tornado.web.RequestHandler):
        def get(self):
            self.render('index.html')
        def post(self, *args, **kwargs):
            # for i in  dir(self.request):
            #     print i
            # print self.request.arguments
            # print self.request.files
            # print self.request.query
            # name_list = self.request.arguments.keys() + self.request.files.keys()
            # print name_list
    
            # list_form = ListForm(MainForm)
            # list_form.validate(self)
            #
            # print list_form.valid_status
            # print list_form.value_dict
            # print list_form.error_dict
    
            # obj = MainForm()
            # obj.validate(self)
            #
            # print "验证结果:", obj.valid_status
            # print "符合验证结果:", obj.value_dict
            # print "错误信息:"
            # for key, item in obj.error_dict.items():
            #     print key,item
            # print self.get_arguments('favor'),type(self.get_arguments('favor'))
            # print self.get_argument('favor'),type(self.get_argument('favor'))
            # print type(self.get_argument('fff')),self.get_argument('fff')
            # print self.request.files
            # obj = MainForm()
            # obj.validate(self)
            # print obj.valid_status
            # print obj.value_dict
            # print obj.error_dict
            # print self.request,type(self.request)
            # obj.fff.save(self.request)
            # from tornado.httputil import HTTPServerRequest
            # name_list = self.request.arguments.keys() + self.request.files.keys()
            # print name_list
            # print self.request.files,type(self.request.files)
            # print len(self.request.files.get('fff'))
            
            # obj = MainForm()
            # obj.validate(self)
            # print obj.valid_status
            # print obj.value_dict
            # print obj.error_dict
            # obj.fff.save(self.request)
            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()
    Form验证框架
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  • 原文地址:https://www.cnblogs.com/sunshuhai/p/9153727.html
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