How to make ball bounce off wall with Pygame?

Question

Before you criticize me for not googling or do research before asking, I did research beforehand but to no avail.

I am trying to create the Atari Br

Answer 1

The issue are the multiple nested loops. You have an application loop, so use it.
Continuously move the ball in the loop:

box.y -= box.vel_y        
box.x += box.vel_x

Define a rectangular region for the ball by a pygame.Rect object:

bounds = window.get_rect() # full screen

or

bounds = pygame.Rect(450, 200, 300, 200)  # rectangular region

Change the direction of movement when the ball hits the bounds:

if box.x - box.radius < bounds.left or box.x + box.radius > bounds.right:
    box.vel_x *= -1 
if box.y - box.radius < bounds.top or box.y + box.radius > bounds.bottom:
    box.vel_y *= -1 

See the example:

box = Circle(600,300,10)

run = True
start = False
clock = pygame.time.Clock()

while run:                     
    clock.tick(120)  

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False

    keys = pygame.key.get_pressed()
    if keys[pygame.K_SPACE]:
        start = True

    bounds = pygame.Rect(450, 200, 300, 200)
    if start:
        box.y -= box.vel_y        
        box.x += box.vel_x

        if box.x - box.radius < bounds.left or box.x + box.radius > bounds.right:
            box.vel_x *= -1 
        if box.y - box.radius < bounds.top or box.y + box.radius > bounds.bottom:
            box.vel_y *= -1 

    window.fill((0,0,0))
    pygame.draw.rect(window, (255, 0, 0), bounds, 1)
    pygame.draw.circle(window, (44,176,55), (box.x, box.y), box.radius)
    pygame.display.update()

Answer 2

it is quite simple. just say if it hits the left or right sides, then multiply the x movement value by -1, and if it hits the top or bottom, then multiply the y movement value by -1