• Python的WEB框架

    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。

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    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：
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      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

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    #!/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

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

    2、动态路由

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    @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

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    @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
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    #!/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：

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

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

    defined(name)

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    # 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)

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    # 获取某个变量的值，不存在时可设置默认值

    setdefault(name, default)

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    # 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：

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    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：

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    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：

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    #!/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

    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

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    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

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    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：

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    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
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    #!/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：

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    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

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

    b.模板引擎

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    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

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    #!/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
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    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

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    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)
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    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
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    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

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    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/

    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。）

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    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

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    #!/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。

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    #!/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 if、for、while 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
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    #!/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：

    • escape: tornado.escape.xhtml_escape 的別名
    • xhtml_escape: tornado.escape.xhtml_escape 的別名
    • url_escape: tornado.escape.url_escape 的別名
    • json_encode: tornado.escape.json_encode 的別名
    • squeeze: tornado.escape.squeeze 的別名
    • linkify: tornado.escape.linkify 的別名
    • datetime: Python 的 datetime 模组
    • handler: 当前的 RequestHandler 对象
    • request: handler.request 的別名
    • current_user: handler.current_user 的別名
    • locale: handler.locale 的別名
    • _: handler.locale.translate 的別名
    • static_url: for handler.static_url 的別名
    • xsrf_form_html: handler.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

    备注：静态文件缓存的实现

        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

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    #!/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

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    #!/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

    #!/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
    ?
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    #!/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/AbnerLc/p/11834211.html
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