import pygame

pygame.init()
window = pygame.display.set_mode([800,580])

X = 200
Y = 200
speedX = 1
speedY = 1
clock = pygame.time.Clock()

while True:
    window.fill((255,255,255))

    pygame.draw.circle(
      window,
      [255,0,0],
      [X,Y],
      70
    )

    X += speedX
    Y += speedY

    if X < 70 or X > 730:
      speedX= -speedX;
    if Y < 70 or Y > 510:
      speedY = -speedY;

    pygame.display.update()
    clock.tick(60)