old_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  # Private module
  from lib.book import (GetHandler, EditHandler,
                        DeleteHandler)
  from lib.auth import (AuthHandler, LoginHandler,
                        LogoutHandler, RegisterHandler)
  from lib import superuuid
  # Public module
  import tornado.locale
  import tornado.httpserver
  import tornado.ioloop
  import tornado.web
  import pymongo
  
  from tornado.options import define, options
  
  # DEFINE
  define("port", default=8000, type=int, help="run on the given port")
  define("mongodb_host", default="127.0.0.1", help="database host")
  define("mongodb_port", default=27017, help="database port")
  define("mongodb_db", default="continue", help="database name")
  
  
  class Application(tornado.web.Application):
      def __init__(self):
          handlers = [
              (r"/book/get", GetHandler),
              (r"/book/edit", EditHandler),
              (r"/book/delete/([0-9]+)", DeleteHandler),
              (r"/auth", AuthHandler),
              (r"/auth/login", LoginHandler),
              (r"/auth/logout", LogoutHandler),
              (r"/auth/register", RegisterHandler)
              # Add new Handler HERE
          ]
          settings = {
              "login_url": "/auth/login",
              # Suite to one instance
              "cookie_secret": superuuid.generate(),
              "debug": True
          }
          tornado.web.Application.__init__(self, handlers, **settings)
  
          conn = pymongo.Connection(options.mongodb_host,
                                    options.mongodb_port)
          self.db = conn[options.mongodb_db]
  
  
  def main():
      tornado.options.parse_command_line()
      http_server = tornado.httpserver.HTTPServer(Application())
      http_server.listen(options.port)
      tornado.ioloop.IOLoop.instance().start()
  
  
  if __name__ == "__main__":
      main()
new_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  # Private module
  from lib.book import (GetHandler, EditHandler,
                        DeleteHandler)
  from lib.auth import (AuthHandler, LoginHandler,
                        LogoutHandler, RegisterHandler)
  from lib import superuuid
  # Public module
  import tornado.locale
  import tornado.httpserver
  import tornado.ioloop
  import tornado.web
  import pymongo
  
  from tornado.options import define, options
  
  # DEFINE
  define("port", default=8000, type=int, help="run on the given port")
  define("mongodb_host", default="127.0.0.1", help="database host")
  define("mongodb_port", default=27017, help="database port")
  define("mongodb_db", default="continue", help="database name")
  
  
  class Application(tornado.web.Application):
      def __init__(self):
          handlers = [
              (r"/book/get", GetHandler),
              (r"/book/edit", EditHandler),
              (r"/book/delete/([0-9]+)", DeleteHandler),
              (r"/auth/", AuthHandler),
              (r"/auth/login", LoginHandler),
              (r"/auth/logout", LogoutHandler),
              (r"/auth/register", RegisterHandler)
              # Add new Handler HERE
          ]
          settings = {
              "login_url": "/auth/login",
              # Suite to one instance
              "cookie_secret": superuuid.generate(),
              "debug": True
          }
          tornado.web.Application.__init__(self, handlers, **settings)
  
          conn = pymongo.Connection(options.mongodb_host,
                                    options.mongodb_port)
          self.db = conn[options.mongodb_db]
  
  
  def main():
      tornado.options.parse_command_line()
      http_server = tornado.httpserver.HTTPServer(Application())
      http_server.listen(options.port)
      tornado.ioloop.IOLoop.instance().start()
  
  
  if __name__ == "__main__":
      main()
subject: Fix bug - /auth/ 404