Tornado user authentication example

Another example from mehmetkose
https://github.com/mehmetkose/tornado-user-authentication-example/blob/master/app.py

import tornado.httpserver
import tornado.ioloop
import tornado.web
import tornado.options
import os.path
from tornado.options import define, options

define("port", default=8000, help="run on the given port", type=int)

class BaseHandler(tornado.web.RequestHandler):
 def get_current_user(self):
  return self.get_secure_cookie("user")
  
class MainHandler(BaseHandler):
 @tornado.web.authenticated
 def get(self):
  self.render('index.html', user=self.current_user)

class LoginHandler(BaseHandler):
 def get(self):
  self.render('login.html')
 def post(self):
  getusername = self.get_argument("username")
  getpassword = self.get_argument("password")
  if "demo" == getusername and "demo" == getpassword:
      self.set_secure_cookie("user", self.get_argument("username"))
      self.redirect("/")
  else:
      wrong=self.get_secure_cookie("wrong")
      if wrong==False or wrong == None:
          wrong=0  
      self.set_secure_cookie("wrong", str(int(wrong)+1))
      self.write('Kullanici Adi veya Sifre Yanlis <a href="/login">Geri</a> '+str(wrong))

class LogoutHandler(BaseHandler):
    def get(self):
        self.clear_cookie("user")
        self.redirect(self.get_argument("next", "/"))

class Application(tornado.web.Application):
    def __init__(self):
        base_dir = os.path.dirname(__file__)
        settings = {
            "cookie_secret": "bZJc2sWbQLKos6GkHn/VB9oXwQt8S0R0kRvJ5/xJ89E=",
            "login_url": "/login",
   'template_path': os.path.join(base_dir, "templates"),
   'static_path': os.path.join(base_dir, "static"),
   'debug':True,
   "xsrf_cookies": True,
  }
  
        tornado.web.Application.__init__(self, [
            tornado.web.url(r"/", MainHandler, name="main"),
            tornado.web.url(r'/login', LoginHandler, name="login"),
            tornado.web.url(r'/logout', LogoutHandler, name="logout"),
        ], **settings)

def main():
    tornado.options.parse_command_line()
    Application().listen(options.port)
    tornado.ioloop.IOLoop.instance().start()

if __name__ == "__main__":
    main()