我可以通过按键改变pygame对象的恒定移动方向吗？

import pygame
pygame.init()

window_width = 800
window_height = 600
window = pygame.display.set_mode((window_width, window_height))
object_rect = pygame.Rect(0, 0, 50, 50)  # 创建一个矩形对象

object_speed = 5  # 对象的移动速度
object_direction = "right"  # 对象的初始移动方向

running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                object_direction = "left"
            elif event.key == pygame.K_RIGHT:
                object_direction = "right"
            elif event.key == pygame.K_UP:
                object_direction = "up"
            elif event.key == pygame.K_DOWN:
                object_direction = "down"

    if object_direction == "left":
        object_rect.x -= object_speed
    elif object_direction == "right":
        object_rect.x += object_speed
    elif object_direction == "up":
        object_rect.y -= object_speed
    elif object_direction == "down":
        object_rect.y += object_speed

    window.fill((0, 0, 0))  # 清空窗口
    pygame.draw.rect(window, (255, 255, 255), object_rect)  # 绘制对象
    pygame.display.flip()  # 更新窗口显示

pygame.quit()