class Player():
    def __init__(self, str, vit, agi, hp):
        self.str = str
        self.agi = agi
        self.vit = vit
        self.hp = hp

    def level_up(self, stat):
        if stat == 'agi':
            self.agi += 1
        elif stat == 'vit':
            self.vit += 1
        else:
            self.str += 1


my_hero = Player(10, 15, 8, 100)
print(my_hero.str, my_hero.agi, my_hero.vit, my_hero.hp)
my_hero.level_up("agi")
print(my_hero.str, my_hero.agi, my_hero.vit, my_hero.hp)