import pygame
#%% create window.
pygame.init()

SCREENWIDTH = 800
SCREENHIEGHT = 600
screen = pygame.display.set_mode((SCREENWIDTH, SCREENHIEGHT))

#%% the player
player = pygame.Rect((300,250, 50, 50))

#%% keep window open, until click exit.
run = True
while run:
    screen.fill((0,0,0))
    pygame.draw.rect(screen, (255,0,0), player)
    key = pygame.key.get_pressed()
    if key[pygame.K_a]==True:
        player.move_ip(-1,0)
    if key[pygame.K_d]==True:
        player.move_ip(1,0)
    if key[pygame.K_w]==True:
        player.move_ip(0,-1)
    if key[pygame.K_s]==True:
        player.move_ip(0,1)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False
    pygame.display.update()
#%% close window.      
pygame.quit()