I am making pong with pygame and Python is reading my variables as if they are in the local scope rather than the global scope. This is the relevant piece of code: import pygame import sys import random pygame.init #the intial starting code to intialize pygame and the screen, as well as associated objects screen = pygame.display.set_mode((640, 480)) pygame.display.set_caption("Screen Display Test") clock = pygame.time.Clock() #defines an objects x position obj_x_pos = [615, 320] #defines an objects y position obj_y_pos = [100, 240] #assigns in each point in the x and y lists an object obj_ref_list = [pygame.image.load("Sprites/paddle.png"), pygame.image.load("Sprites/ball.png") ] print(obj_x_pos) #defines the list the holds an objects x and y position for display output rend_positions = [] ball_movex = random.randint(-5, 5) ball_movey = random.randint(-5, 5) while ball_movex == ball_movey: ball_movex = random.randint(-5, 5) ball_movey = random.randint(-5, 5) #defines the function to declare an object movement as the player def player_movement(obj_index, move_speed): button_presses = pygame.key.get_pressed() if button_presses[pygame.K_s]: obj_y_pos[obj_index] += move_speed if button_presses[pygame.K_w]: obj_y_pos[obj_index] -= move_speed #function which draw objects to the screen by taking their reference number, then inputting the corresponding x, y and display information def draw_object(ref_number): rend_positions = [obj_x_pos[ref_number], obj_y_pos[ref_number]] screen.blit(obj_ref_list[ref_number], rend_positions) def ball_movement(obj_index): obj_x_pos[obj_index] += ball_movex obj_y_pos[obj_index] += ball_movey if obj_x_pos[obj_index] <= 0: ball_movex = ball_movex * -1 if obj_x_pos[obj_index] >= 605: ball_movex = ball_movex * -1 if obj_y_pos[obj_index] <= 0: ball_movey = ball_movey * -1 if obj_y_pos[obj_index] >= 470: ball_movey = ball_movey * -1 #runs the game loop while True: #calls the function to draw an object on screen draw_object(0) draw_object(1) #calls the function that moves the player player_movement(0, 2) ball_movement(1) #allows the game window to close and function without windows problems for event in pygame.event.get(): if event.type == pygame.QUIT: pygame.quit() sys.exit() #updates the display every frame pygame.display.update() screen.fill((0, 0, 0)) #locks the frame rate to 60 fps clock.tick(60) this just throws a traceback error stating that in the first line of the function is "contains no value". It should just print the number The particular error is: Traceback (most recent call last): File "game.py", line 63, in <module> ball_movement(1) File "game.py", line 44, in ball_movement obj_x_pos[obj_index] += ball_movex ^^^^^^^^^^ UnboundLocalError: cannot access local variable 'ball_movex' where it is not associated with a value Continue reading...
