class Player:
    def __init__(self): 
        self.hp = 10
        self.pos = [0,0,0]
        self.items = []
    def damage(self,dmg):
        self.hp += dmg

player = Player()
player.damage(3)
player.pos[0] += 5
player.items.push("banana")

print player.hp, player.pos, player.items
>> 5 [5,0,0] ["banana"]