データと表示と操作を分離させてみた

data_separation.py

class Data:
    def __init__(self):
        self._HP = 100
        self._MP = 50
        self.hp_lim = (0, self._HP)
        self.mp_lim = (0, self._MP)

    @property
    def HP(self):
        return self._HP

    @HP.setter
    def HP(self, value):
        if value <= self.hp_lim[0]:
            self._HP = self.hp_lim[0]
        elif value >= self.hp_lim[1]:
            self._HP = self.hp_lim[1]
        else:
            self._HP = value

    @property
    def MP(self):
        return self._MP

    @MP.setter
    def MP(self, value):
        if value <= self.mp_lim[0]:
            self._MP = self.mp_lim[0]
        elif value >= self.mp_lim[1]:
            self._MP = self.mp_lim[1]
        else:
            self._MP = value


class Visual:
    @staticmethod
    def show(data):
        print("HP:{}".format(data.HP))
        print("MP:{}".format(data.MP))
        print()


class Method:
    def __init__(self, data):
        self._data = data

    def Damage(self, value):
        self._data.HP -= value

    def Heal(self, value):
        self._data.HP += value

    def Spend(self, value):
        self._data.MP -= value


def main():
    d = Data()
    m = Method(d)
    Visual().show(d)

    m.Damage(20)
    Visual().show(d)

    m.Heal(15)
    Visual().show(d)


if __name__ == '__main__':
    main()