def get_rps_list(self):
        """
        get list of each second's rps
        :returns: list of tuples (rps, duration of corresponding rps in seconds)
        :rtype: list
        """
        seconds = range(0, int(self.duration) + 1)
        rps_groups = groupby([proper_round(self.rps_at(t)) for t in seconds],
                             lambda x: x)
        rps_list = [(rps, len(list(rpl))) for rps, rpl in rps_groups]
        return rps_list