import pygame
from pygame.locals import *
from sys import exit
from random import randint

# Random Rectangle Demonstration

pygame.init()

screen = pygame.display.set_mode((640, 480), 0, 32)

while True:
    
    for event in pygame.event.get():
        if event.type == QUIT:
            pygame.quit()
            quit()
    
    # Lock the screen
    screen.lock()
    for count in range(10):
        random_color = (randint(0,255), randint(0,255), randint(0,255))
        random_pos = (randint(0,639), randint(0, 479))
        random_size = (639 - randint(random_pos[0], 639) , 479 - randint(random_pos[1], 479))
        pygame.draw.rect(screen, random_color, Rect(random_pos, random_size))
    # don't forget to unlock it
    screen.unlock()  
    pygame.display.update()
    
    