Tornado PyMongo product wishlist
You can try editing your BaseHandler like this

class BaseHandler(tornado.web.RequestHandler):
    def prepare(self):
        self.user_email = self.get_secure_cookie('trakr')
        self.user_db = self.application.db.users


and then call the  following in your other Handlers 

self.userdb.update({'email_id': self.user_email},


Basically the prepare function is called right at the beginning of the request
for more information you can look at the tornado docs