我想让pygame中的这个立方体在我更新的时候移动。

import pygame
pygame.init()

window_width = 800
window_height = 600
window = pygame.display.set_mode((window_width, window_height))
pygame.display.set_caption("立方体移动示例")

cube_size = 50
cube_x = window_width // 2 - cube_size // 2
cube_y = window_height // 2 - cube_size // 2
cube_speed = 5

running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
    
    keys = pygame.key.get_pressed()
    if keys[pygame.K_LEFT]:
        cube_x -= cube_speed
    if keys[pygame.K_RIGHT]:
        cube_x += cube_speed
    if keys[pygame.K_UP]:
        cube_y -= cube_speed
    if keys[pygame.K_DOWN]:
        cube_y += cube_speed

    window.fill((255, 255, 255))  # 清空窗口
    pygame.draw.rect(window, (0, 0, 0), (cube_x, cube_y, cube_size, cube_size))  # 绘制立方体
    pygame.display.update()  # 更新窗口

pygame.quit()