python – 吃豆人 – 一旦按下并释放一个键,让pacman向一个方向

所以,我想用pygame模块在 python3中编写pac-man.但是,一旦按下一个键,我不知道怎样让pac-man移动.目的是按下例如“向上”键,并且pac-man将继续朝那个方向移动,直到他击中边界,即使我释放了键.截至目前,我没有编码这些边界,因为我优先考虑pac-man的连续运动.我试图嵌套一个应该工作的while循环,但这显然给了我一个phat运行时错误.有关如何做到这一点的任何想法？

if keys[pygame.K_UP] and (pac.y - pac.radius) > 0:
        pac.y -= pac.speed
        pac.direction = "UP"
    elif keys[pygame.K_DOWN] and (pac.y + 2*(pac.radius) + pac.speed) < height:
        pac.y += pac.speed
        pac.direction = "DOWN"
    elif keys[pygame.K_LEFT] and (pac.x - pac.radius) > 0:
        pac.x -= pac.speed
        pac.direction = "LEFT"
        left = True
    elif keys[pygame.K_RIGHT] and (pac.x + 2*pac.radius + pac.speed) < width:
        pac.x += pac.speed
        pac.direction = "RIGHT"
        right = True

预期的结果是输入单个方向,并且pac man将自己朝那个方向移动而不需要按住键.实际上发生的事情是我最终不得不按住钥匙,这样pac人就会朝着想要的方向前进.

def update():
    pac.y += pac.yspeed
    pac.x += pac.xspeed


while True:
    clock.tick(60)
    if keys[pygame.K_UP] and (pac.y - pac.radius) > 0:
        pac.yspeed = 1
    elif keys[pygame.K_DOWN] and (pac.y + 2*(pac.radius) + pac.speed) < height:
        pac.yspeed = -1
    elif keys[pygame.K_LEFT] and (pac.x - pac.radius) > 0:
        pac.xspeed = -1
        left = True
    elif keys[pygame.K_RIGHT] and (pac.x + 2*pac.radius + pac.speed) < width:
        pac.xspeed = 1
        right = True
    if keys[pygame.K_ESC]:
        break
    update()
    # Do all your other stuff