def unlock(self):
     if self.is_locked and redis.set(DOOR_LOCK_KEY, 0):
         self._lock = False
         return True
     else:
         return False
 def lock(self):
     if (self.is_locked == False) and redis.set(DOOR_LOCK_KEY, 1):
         self._lock = True
         return True
     else:
         return False