Pygame Lesson One | Random Balls

#blue box
import pygame
import random

#variable
run = True
#init pygame
pygame.init()

#screen
screen = pygame.display.set_mode((800,600))

#title
pygame.display.set_caption("Blue sky")

#game loop
while run:
    #handle event
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False
            quit()

    #colo screen
    screen.fill((135,206,235))

    #coordinates
    x = random.randint(10,790)
    y = random.randint(10,590)

    #radius
    r = random.randint(2,18)

    #draw circle
    pygame.draw.circle(screen, (0,0,150),(x,y),r)

    #update the screen
    pygame.display.flip()