Pygame 没有移动我的矩形，我不知道为什么？

Question

I dont know why but my character is in the display but it cant move it is in a sprite group and it is updated all the time

class player(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image  = pygame.Surface( (30 , 30))
        self.image.fill (red)
        self.rect = self.image.get_rect ()
        self.rect.y = height /2
        self.rect.x = width-50
        self.speedy = 0


    def update(self):
        self.speedy = 0
        keystate = pygame.key.get_pressed()
        if keystate[pygame.K_UP]:
            self.speedy = 8

        if keystate[pygame.K_DOWN]:
            self.speedy = -8
        if self.rect.bottom >= height:
            self.rect.top = 0
        if self.rect.top <= 0:
            self.rect.bottom = height

Answer 1

You have to continuously change the position of the ".rect" attribute in the "update" method by "speedy":

self.rect.y += self.speedy

Ensure thatpygame.sprite.Group.update is invoked in every frame and change the position after evaluating the speed:

class player(pygame.sprite.Sprite):
    # [...]

    def update(self):
        self.speedy = 0
        keystate = pygame.key.get_pressed()
        if keystate[pygame.K_UP]:
            self.speedy = 8
        if keystate[pygame.K_DOWN]:
            self.speedy = -8

        self.rect.y += self.speedy

        if self.rect.bottom >= height:
            self.rect.top = 0
        if self.rect.top <= 0:
            self.rect.bottom = height