setting objects inside of objects that are dependant on eachother (Python)-CodePudding

I am attempting to insert enemies to my game, this one is called punching_bag, and I have made another object that is inside of punching_bag that is under the DangerZone class.

I want the DangerZone class to be next to the punching_bag. Hence the punching_bag.x - 64. But I am running into problems, because punching_bag.x doesn't exist yet I can not refer to it

Enemy Class

class Enemy:
    def __init__(self, sprite, x, y, health, attack):
        self.sprite = sprite
        self.x = x
        self.y = y
        self.health = health
        self.attack = attack

DangerZone Class

class DangerZone:
    def __init__(self, sprite, x, y, damage):
        self.sprite = sprite
        self.x = x
        self.y = y
        self.damage = damage

punching_bag Object

punch_bag = Enemy(sprite junk, 640, 0, 10,
              DangerZone(sprite junk, punch_bag.x - 64, punch_bag.y, 1)
              )

CodePudding user response：

You are correct. You are attempting to reference an attribute of an object that doesn't yet exist. But when it does exist, you know its x attribute is going to have the value 640, and y will have 0, right? So why not just do:

punch_bag = Enemy(sprite junk, 640, 0, 10,
              DangerZone(sprite junk, 640 - 64, 0, 1)
              )

You could wrap this in a factory function that took an x and y to be clearer what those values are and to make sure that the two uses of each provide the same value. So maybe:

class Enemy:
    def __init__(self, sprite, x, y, health, attack):
        self.sprite = sprite
        self.x = x
        self.y = y
        self.health = health
        self.attack = attack

   @staticmethod 
   def create_with_danger_zone(sprite_junk, x, y, health, attack):
      return Enemy(sprite_junk, x, y, health,
                      DangerZone(sprite_junk, x - 64, y, 1))

punch_bag = Enemy.create_with_danger_zone(sprite_junk, 640, 0, 10)