对象之间的Python Pygame碰撞检测

您好，对很多问题感到抱歉，但我再次认识python，但我正在尝试学习pygame。在游戏中，我正在尝试使之进入游戏，因此当块/图像接触到精灵时，它会回到屏幕顶部。我看过许多教程，但似乎无法以一种很好的方式来理解它。有什么建议吗？这是代码，谢谢！！！：

import pygame
import sys
from random import randint
import os

x = 250
y = 30

os.environ["SDL_VIDEO_WINDOW_POS"] = "%d,%d" % (x, y)

width = 1024
height = 768

icon1 = pygame.image.load("Firstpygamegame/santa-claus.png")
pygame.display.set_icon(icon1)

screen = pygame.display.set_mode((width, height))
pygame.display.set_caption("Gift Catcher")
background_image = pygame.image.load("Firstpygamegame/wintervillage.png")

sprite1 = pygame.image.load("Firstpygamegame/santabag2.png")
spriterect = sprite1.get_rect()
speed = 2.5
# 442 or 467
spriterect.x = 442
icon2 = pygame.image.load("Firstpygamegame/present1.png")
icon3 = pygame.image.load("Firstpygamegame/present2.png")
icon4 = pygame.image.load("Firstpygamegame/present3.png")
icon5 = pygame.image.load("Firstpygamegame/present4.png")

cubes = [[
    randint(1, 1000),  # X coordinate
    randint(-1500, -350)]  # Y coordinate, -Y is above screen  (top of screen is zero)
    for x in range(2)]  # 20 cubes

cubes1 = [[
    randint(1, 1000),  # X coordinate
    randint(-1500, -150)]  # Y coordinate, -Y is above screen  (top of screen is zero)
    for x in range(2)]  # 20 cubes

cubes2 = [[
    randint(1, 1000),  # X coordinate
    randint(-1500, -550)]  # Y coordinate, -Y is above screen  (top of screen is zero)
    for x in range(2)]  # 20 cubes

cubes3 = [[
    randint(1, 1000),  # X coordinate
    randint(-1500, -450)]  # Y coordinate, -Y is above screen  (top of screen is zero)
    for x in range(2)]  # 20 cubes

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

    keys = pygame.key.get_pressed()
    spriterect.x += (keys[pygame.K_RIGHT] - keys[pygame.K_LEFT]) * speed
    spriterect.y = 600

    screen.blit(background_image, (0, 0))
    screen.blit(sprite1, spriterect)

    for cb in cubes:
        cb[1] += .25  # cube moves down 2 pixels
        screen.blit(icon2, cb)  # draw cube
        if cb[1] > 800:  # if cube passed bottom of screen
            cb[1] = -100  # move to above screen
            cb[0] = randint(1, 1000)

    for cb in cubes1:
        cb[1] += .25  # cube moves down 2 pixels
        screen.blit(icon3, cb)  # draw cube
        if cb[1] > 800:  # if cube passed bottom of screen
            cb[1] = -100  # move to above screen
            cb[0] = randint(1, 1000)  # random X position

    for cb in cubes2:
        cb[1] += .25  # cube moves down 2 pixels
        screen.blit(icon4, cb)  # draw cube
        if cb[1] > 800:  # if cube passed bottom of screen
            cb[1] = -100  # move to above screen
            cb[0] = randint(1, 1000)  # random X position

    for cb in cubes3:
        cb[1] += .25  # cube moves down 2 pixels
        screen.blit(icon5, cb)  # draw cube
        if cb[1] > 800:  # if cube passed bottom of screen
            cb[1] = -100  # move to above screen
            cb[0] = randint(1, 1000)  # random X position

    pygame.display.flip()