一、快速上手
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web class MainHandler(tornado.web.RequestHandler): def get(self): self.write("Hello, world") application = tornado.web.Application([ (r"/index", MainHandler), ]) if __name__ == "__main__": application.listen(8888) tornado.ioloop.IOLoop.instance().start()
第一步:执行脚本,监听 8888 端口
第二步:浏览器客户端访问 /index --> http://127.0.0.1:8888/index
第三步:服务器接受请求,并交由对应的类处理该请求
第四步:类接受到请求之后,根据请求方式(post / get / delete ...)的不同调用并执行相应的方法
第五步:方法返回值的字符串内容发送浏览器
二、路由系统
路由系统其实就是 url 和 类 的对应关系,这里不同于其他框架,其他很多框架均是 url 对应 函数,Tornado中每个url对应的是一个类。
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web class MainHandler(tornado.web.RequestHandler): def get(self): self.write("Hello, world") class StoryHandler(tornado.web.RequestHandler): def get(self, story_id): self.write("You requested the story " + story_id) class BuyHandler(tornado.web.RequestHandler): def get(self): self.write("buy.wupeiqi.com/index") application = tornado.web.Application([ (r"/index", MainHandler), (r"/story/([0-9]+)", StoryHandler), ]) application.add_handlers('buy.wupeiqi.com$', [ (r'/index',BuyHandler), ]) if __name__ == "__main__": application.listen(80) tornado.ioloop.IOLoop.instance().start()
三、模板
Tornao中的模板语言和django中类似,模板引擎将模板文件载入内存,然后将数据嵌入其中,最终获取到一个完整的字符串,再将字符串返回给请求者。
Tornado 的模板支持“控制语句”和“表达语句”,控制语句是使用 {%
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。
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/> <title>123456</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>
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
{% extends 'layout.html'%} {% block CSS %} <link href="{{static_url("css/index.css")}}" rel="stylesheet" /> <link href="/static/css/common.css" rel="stylesheet" /> {% end %} {% block RenderBody %} <h1>Index</h1> {% end %} {% block JavaScript %} {% end %}
#!/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') settings = { 'template_path': 'template', 'static_path': 'static', 'static_url_prefix': '/static/', } application = tornado.web.Application([ (r"/index", MainHandler), ], **settings) if __name__ == "__main__": application.listen(8888) 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
: forhandler.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
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
# uimethods.py def tab(self): return 'UIMethod'
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#!/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>chenchao</h1>')
2、注册
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#!/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
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
<!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>
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。
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web 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(8888) tornado.ioloop.IOLoop.instance().start()
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/> <title>123456</title> <link href="{{static_url("css/common.css")}}" rel="stylesheet" /> </head> <body> <div class="pg-header"> <h1>Index</h1> </div> <script src="{{static_url("js/jquery-1.8.2.min.js")}}"></script> </body> </html>
备注:静态文件缓存的实现
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
def get_content_version(cls, abspath): 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()
2、csrf
Tornado中的跨站请求伪造和Django中的相似,跨站伪造请求(Cross-site request forgery)
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
settings = { "xsrf_cookies": True, } application = tornado.web.Application([ (r"/", MainHandler), (r"/login", LoginHandler), ], **settings)
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
<form action="/new_message" method="post"> {{ xsrf_form_html() }} <input type="text" name="message"/> <input type="submit" value="Post"/> </form>
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
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 + ")")); }}); };
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进行签名以防止伪造。
a、基本操作
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
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!")
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:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
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=")
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。
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#!/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', '陈超') 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()
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#!/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', '陈超') 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()
五、扩展功能
1、自定义Session
a.知识储备
类的特殊成员
#!/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'] = 'chenchao' #del obj['k1']
b.session实现机制
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web from hashlib import sha1 import os, time session_container = {}
# 创建MD516进制的session_id create_session_id = lambda: sha1('%s%s' % (os.urandom(16), time.time())).hexdigest() class Session(object): session_id = "__sessionId__" # 自定义session的key名称 def __init__(self, request):
# 默认先从请求信息里获取自定义的cookie值 session_value = request.get_cookie(Session.session_id) if not session_value: self._id = create_session_id() else: self._id = session_value
# 设置cookie 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): # 创建Session的对象,将MainHandler的对象传入 self.my_session = Session(self)
# 继承自定义的BaseHandler class MainHandler(BaseHandler): def get(self): print self.my_session['c_user'] # 获取session的值 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 == 'chenchao' and password == '123':
# 设置session的值 self.my_session['c_user'] = 'chenchao' 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()
2、自定义模型绑定
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!!!
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
<!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>
#!/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}$' def check_valid(self, request): form_dict = self.__dict__ for key, regular in form_dict.items(): post_value = request.get_argument(key) # 让提交的数据 和 定义的正则表达式进行匹配 ret = re.match(regular, post_value) print key,ret,post_value class MainHandler(tornado.web.RequestHandler): def get(self): self.render('index.html') def post(self, *args, **kwargs): obj = MainForm() result = obj.check_valid(self) self.write('ok') settings = { 'template_path': 'template', 'static_path': 'static', 'static_url_prefix': '/static/', 'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh', 'login_url': '/login' } application = tornado.web.Application([ (r"/index", MainHandler), ], **settings) if __name__ == "__main__": application.listen(8888) tornado.ioloop.IOLoop.instance().start()
由于请求的验证时,需要考虑是否可以为空以及正则表达式的复用,所以:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web import re class Field(object): def __init__(self, error_msg_dict, required): self.id_valid = False self.value = None self.error = None self.name = None self.error_msg = error_msg_dict self.required = required def match(self, name, value): self.name = name if not self.required: self.id_valid = True self.value = value else: if not value: if self.error_msg.get('required', None): self.error = self.error_msg['required'] else: self.error = "%s is required" % name else: ret = re.match(self.REGULAR, value) if ret: self.id_valid = True self.value = ret.group() else: if self.error_msg.get('valid', None): self.error = self.error_msg['valid'] else: self.error = "%s is invalid" % name class IPField(Field): REGULAR = "^(25[0-5]|2[0-4]d|[0-1]?d?d)(.(25[0-5]|2[0-4]d|[0-1]?d?d)){3}$" 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