$ sudo apt-get install update
$ sudo apt-get install mongodb

$ pip install motor

# conf.py

import os
import motor
from handlers import index, auth

BASE_DIR = os.path.join(__file__)

handlers = [
  (r'^/$', index.IndexHandler),
  (r'^/auth/register$', auth.RegisterHandler),
  (r'^/auth/login$', auth.LoginHandler),
]

settings = dict(
  debug = True,
  template_path = os.path.join(BASE_DIR, 'templates'),
  static_path = os.path.join(BASE_DIR, 'static'),
)

client = motor.MotorClient("127.0.0.1")
db = client.meet

 # handlers/__init__.py
class BaseHandler(tornado.web.RequestHandler, TemplateRendering):
  def initialite(self):
    ...

  @property
  def db(self):
    return self.application.db

# auth.py

import os 
import time 
import tornado.web
from tornado import gen
from . import BaseHandler

class RegisterHandler(BaseHandler):
  def get(self):
    self.render_html('register.html')

  @tornado.web.asynchronous
  @gen.coroutine
  def post(self):
    username = self.get_argument('username', None)
    email = self.get_argument('email', None)
    password = self.get_argument('password', None)

    data = {
      'username': username,
      'email': email,
      'password': password,
      'timestamp': time.time() * 1000,
    }

    if username and email:
      yield self.db.user.insert(data)
    self.redirect('/')

class LoginHandler(BaseHandler):
  
  @tornado.web.asynchronous
  @gen.coroutine
  def get(self):
    username = self.get_argument('useranme')
    user = yield self.db.user.find_one({'username': username})
    self.render_html('login.html', user=user)

# 之前
yield self.db.user.insert(data)

# 之后
yield tornado.gen.Task(tornado.ioloop.IOLoop.instance().add_timeout, time.time() + 10)

class Register(BaseHandler):
  def get(self):
    self.render_html('register.html')

  @tornado.web.aynchronous
  @gen.coroutine
  def post(self):
    username = self.get_argument('username')
    email = self.get_argument('email')
    password = self.get_argument('password')
    captcha = self.get_argument('captcha')

    _verify_username = yield self.db.user.find_one({'username': username})
    if _verify_username:
      self.flash(u'用户名已存在', 'error')
      self.redirect('/auth/register')

    _verify_email = yield self.db.user.find_one({'email': email})
    if _verify_email:
      self.flash(u'邮箱已注册', 'error')
      self.redirect('/auth/register')

    if captcha and captcha == self.get_secure_cookie('captcha').replace(' ',''):
      self.flash(u'验证码输入正确', 'info')
    else:
      self.flash(u'验证码输入错误', 'error')
      self.redirect('/auth/register')

    password = haslib.md5(password + self.settings['site']).hexdigest()

    profile = {'headimg': '', 'site': '', 'job': '', 'signature':'',
          'github': '', 'description': ''}
    user_profile = yield self.db.profile.insert(profile)
    user = {'username': username, 'email': email, 'password': password,
        'timestamp': time.time(), 'profile_id': str(user_profile)}

    yield self.db.user.insert(user)
    self.set_secure_cookie('user', username)
    self.redirect('/')

return self.redirect('/auth/register')

self.redirect('/auth/register')
return