• Tornado初探


    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

    复制代码
    #!/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()
    复制代码

    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 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。

    复制代码
    <!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>
    复制代码
    复制代码
    {% 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 %}
    复制代码
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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:

    • 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'
    复制代码
    #!/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>')
    复制代码

    2、注册

    复制代码
    #!/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()
    复制代码

    3、使用

    复制代码
    <!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>
    复制代码

    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。

    复制代码
    #!/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()
    复制代码
    复制代码
    <!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>
    复制代码

    备注:静态文件缓存的实现

    复制代码
        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()
    复制代码

    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)

    复制代码
    settings = {
        "xsrf_cookies": True,
    }
    application = tornado.web.Application([
        (r"/", MainHandler),
        (r"/login", LoginHandler),
    ], **settings)
    复制代码
    <form action="/new_message" method="post">
      {{ xsrf_form_html() }}
      <input type="text" name="message"/>
      <input type="submit" value="Post"/>
    </form>
    复制代码
    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 + ")"));
        }});
    };
    复制代码

    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

    复制代码
    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!")
    复制代码

    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:

    复制代码
    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=")
    复制代码
    复制代码
    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())
    复制代码
    复制代码
    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)
    复制代码
    复制代码
    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
    复制代码

    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。

    复制代码
    #!/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()
    复制代码
    复制代码
    #!/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()
    复制代码

    4、Ajax上传文件

    复制代码
    <!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>
    复制代码
    复制代码
    #!/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()
    复制代码
    复制代码
    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);
        }
    })
    复制代码

    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

    复制代码
    #!/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
    
    """
    复制代码
    复制代码
    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)
            
    复制代码

    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!!!

    复制代码
    <!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>
    复制代码
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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:

    复制代码
    #!/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()
    复制代码
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  • 原文地址:https://www.cnblogs.com/hellojesson/p/6547393.html
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