def _has_straight(self, all_cards):
        '''
        Check the existence of straight cards
        Returns:
            True: exist
            False: not exist
        '''
        diff_rank_cards = self._get_different_rank_list(all_cards)
        self.best_five = self._get_straight_cards(diff_rank_cards)
        if len(self.best_five) != 0:
            return True
        else:
            return False

        Check the existence of straight cards
        Returns:
            True: exist
            False: not exist
        
rlcard/games/limitholdem/utils.py