我试图在pygame中编写一个代码，以随机显示箭头精灵（如DDR）。我本来想利用时间，但是睡眠会使整个程序暂停，我只想暂停一个箭头。

我试图创建一个随机列表类型的调用程序，但是这行不通，因为箭头需要先消失才能消失。

import pygame,sys
from pygame.locals import *
from random import randint
from time import sleep

#Variables
WIDTH = 800
HEIGHT = 450
FPS = 30
running = True
BLACK = (0,0)
SALMON = (253,171,159)

screen = pygame.display.set_mode((WIDTH,HEIGHT))
pygame.display.set_caption("Tempoify")

pygame.init()
pygame.mixer.init()
clock = pygame.time.Clock()

#####################################
# Gray Arrows

class ArrowRightGray(pygame.sprite.Sprite):

  def __init__(self):
    pygame.sprite.Sprite.__init__(self)
    self.image = pygame.image.load("gray right.png").convert()
    self.image.set_colorkey(BLACK)
    self.rect = self.image.get_rect()
    self.rect.center = (750,25)


class ArrowLeftGray(pygame.sprite.Sprite):

  def __init__(self):
    pygame.sprite.Sprite.__init__(self)
    self.image = pygame.image.load("gray left.png").convert()
    self.image.set_colorkey(BLACK)
    self.rect = self.image.get_rect()
    self.rect.center = (750,125)


class ArrowUpGray(pygame.sprite.Sprite):

  def __init__(self):
    pygame.sprite.Sprite.__init__(self)
    self.image = pygame.image.load("gray up.png").convert()
    self.image.set_colorkey(BLACK)
    self.rect = self.image.get_rect()
    self.rect.center = (750,250)

class ArrowDownGray(pygame.sprite.Sprite):

  def __init__(self):
    pygame.sprite.Sprite.__init__(self)
    self.image = pygame.image.load("gray down.png").convert()
    self.image.set_colorkey(BLACK)
    self.rect = self.image.get_rect()
    self.rect.center = (750,375)

class ArrowRight(pygame.sprite.Sprite):

  def __init__(self):
    pygame.sprite.Sprite.__init__(self)
    self.image = pygame.image.load("red right.png").convert()
    self.image.set_colorkey(BLACK)
    self.rect = self.image.get_rect()
    self.rect.center = (25,25)

  def update(self):
    self.rect.x += 5
    if (self.rect.left > (WIDTH + 50)):
        self.rect.right = 0

class ArrowLeft(pygame.sprite.Sprite):

  def __init__(self):
    pygame.sprite.Sprite.__init__(self)
    self.image = pygame.image.load("blue left.png").convert()
    self.image.set_colorkey(BLACK)
    self.rect = self.image.get_rect()
    self.rect.center = (25,125)

  def update(self):
    self.rect.x += 5
    if (self.rect.left > (WIDTH + 50)):
        self.rect.right = 0

class ArrowUp(pygame.sprite.Sprite):

  def __init__(self):
    pygame.sprite.Sprite.__init__(self)
    self.image = pygame.image.load("green up.png").convert()
    self.image.set_colorkey(BLACK)
    self.rect = self.image.get_rect()
    self.rect.center = (25,250)

  def update(self):
    self.rect.x += 5
    if (self.rect.left > (WIDTH + 50)):
        self.rect.right = 0

class ArrowDown(pygame.sprite.Sprite):

  def __init__(self):
    pygame.sprite.Sprite.__init__(self)
    self.image = pygame.image.load("yellow down.png").convert()
    self.image.set_colorkey(BLACK)
    self.rect = self.image.get_rect()
    self.rect.center = (25,375)

  def update(self):
    self.rect.x += 5
    if (self.rect.left > (WIDTH + 50)):
        self.rect.right = 0

allArrows = pygame.sprite.Group()
a1g = ArrowRightGray()
a1 = ArrowRight()

a2g = ArrowLeftGray()
a2 = ArrowLeft()

a3g = ArrowUpGray()
a3 = ArrowUp()

a4g = ArrowDownGray()
a4 = ArrowDown()

allArrows.add(a1g)
allArrows.add(a1)
allArrows.add(a2g)
allArrows.add(a2)
allArrows.add(a3g)
allArrows.add(a3)
allArrows.add(a4g)
allArrows.add(a4)

while running:
  clock.tick(FPS)

  #Update
  allArrows.update()

  keys = pygame.key.get_pressed()

  for event in pygame.event.get():
      if keys[pygame.K_RIGHT]:
          if pygame.sprite.collide_rect(a1,a1g):
              a1.rect.center = (900,600)
      elif keys[pygame.K_LEFT]:
          if pygame.sprite.collide_rect(a2,a2g):
              a2.rect.center = (900,600)
      elif keys[pygame.K_UP]:
          if pygame.sprite.collide_rect(a3,a3g):
              a3.rect.center = (900,600)
      elif keys[pygame.K_DOWN]:
          if pygame.sprite.collide_rect(a4,a4g):
              a4.rect.center = (900,600)
  #draw
  screen.fill(SALMON)
  allArrows.draw(screen)

  pygame.display.flip()

pygame.quit()

最后，箭头应指向屏幕的末端并随机显示。当它们与灰色箭头碰撞时，它们也应该消失。