Getting attribute error on non-attribute variable - python-3.x

Question

Im working on a game and getting a strange error where instance variable isn't saved properly (as far as I can tell). This happens when i try to access self.game from the RunGame instance. By the way the classes are in separate modules, and im not showing all code. The game runs fine, but when switching level it just crashes
class RunGame(object):
def __init__(self):
self.makeTk()
self.currentLevel = 0
self.bricksLayout = [ #for debugging: a layout of bricks. 3d array with each level
[
[0,1,0,1,1,1,1,1],
[0,0,0,0,4,1,1,1],
[4,4,4,4,4,4,4,4]
],
[
[4,0,0,1,0,1,0,1],
[0,0,0,0,0,1,0,1],
[4,4,4,4,4,4,4,4]
]
]
self.game = GameInstance(self.bricksLayout,self)
self.game.run = False #this does nothing for some reason, no error though
def switchLevel(self):
print("switching level")
self.game.run = False #calling this will give no attribute error
#self.game.clearCanvas()
#self.game.canvas.destroy()
self.currentLevel+=1
#self.game = Game(self.bricksLayout,self)
def makeTk(self):
self.root = Tk()
self.root.title("PrakeOut")
self.screen_width = self.root.winfo_screenwidth(); #monitor size
self.screen_height = self.root.winfo_screenheight();
#root.wm_attributes("-fullscreen",True) #this gives fullscreen, but removes the menu
self.root.resizable(0,0) #cant be resized
self.root.configure(background="Black") #bg color of root windw
#root.geometry("%ix%i+0+0" % (SCREEN_WIDTH, SCREEN_HEIGHT)) #maximizes screen. First two are width and height, other two are x1 and y1
#root.wm_attributes("-topmost",1); #places window in foreground
run = RunGame()
class GameInstance(object):
def __init__(self, bricksLayout,gameHandler):
self.bricksLayout = bricksLayout
self.gameHandler = gameHandler
self.run = True #game loop
self.makeCanvas()
self.brickList = [] #the list of all da created bricks
self.makeBricks()
self.makeBallAndPaddle()
self.gameLoop()
self.root.mainloop(); #needs to run main loop otherwise windows doesnt show
It gives this error:
File "C:\Users\Bollen\Desktop\python projects\breakout\PythonApplication1\PythonApplication1\GameHandler.py", line 30, in switchLevel
self.game.run = False #calling this will give no attribute error
AttributeError: 'RunGame' object has no attribute 'game'
Press any key to continue . . .

Answer 1

We can't use your code to reproduce the problem, but there is one very obvious logic error in your code. The problem is that neither of your classes is allowed to be fully created before they are being used.
Take a look at GameInstance: because you call mainloop within the initializer, that class will never be fully instantiated until after the root window has been created and then destroyed. Therefore, any other classes which try to work with this instance will be working with a not-fully-formed instance.
Likewise, with GameRunner you are creating an instance of GameInstance. Because GameInstance calls mainloop, the creation of the GameRunner object cannot be finished before GameInstance has been created, and GameInstance won't be finished until the window is destroyed.
The first step is to remove the call to mainloop from GameInstance.__init__. Instead, move that into a method that GameRunner can call once it is fully created.
You should also separate the creation of the two objects into two steps. Your main logic would then look something like the following./ I'm not sure if you should create the runner first or the game first, but either way is acceptable depending on how you define the classes.
game = GameInstance(...)
runner = GameRunner(..., game)
runner.run()
In the above, runner.run() would look something like this:
class GameRunner(...):
def run(self):
self.game.run()
... and game.run would look like this:
class GameInstance(...):
def run(self):
self.gameLoop()
self.root.mainloop()