当循环遍历嵌套列表时，我一直得到“ValueError:list.remove（x）：x not in list”

Question

我试着做一个简单的太空入侵者的版本，我一直遇到同样的错误

ValueError: list.remove(x): x not in list

试图在入侵者被击中后将其清除。

这是密码。

def killEnemies(bullets, enemies):
    for bullet in bullets:
        for x in enemies:
            for y in x:
                if bullet.top <= y.bottom and bullet.top >= y.top:
                    if bullet.left >= y.left and bullet.right <= y.right:
                        x.remove(y)
                        bullets.remove(bullet)

只有当if语句为True，并且控制台说错误发生在最后一行时，问题才会出现

下面是代码的其余部分

import pygame, sys
from pygame.locals import *


pygame.init()

FPS = 30
fpsClock = pygame.time.Clock()

DISPLAYSURF = pygame.display.set_mode((800, 660), 0, 32)
pygame.display.set_caption('Space Invaders')

white = (255, 255, 255)
black = (0, 0, 0)
shipx = 50
shipy = 630
DISPLAYSURF.fill(black)

timer = fpsClock.tick()
time = 0
direction = ''
bullets = []
bulletx = shipx + 25
bullety = shipy - 50
enemies = [[], [], [], [], [], [], []]
shields = []


def drawEnemies(enemies):
    y = 0
    for n in enemies:
        x = 0
        for f in range(7):
            enemy = pygame.draw.rect(DISPLAYSURF, white, (30 + x, 40 + y, 75, 20))
            n.append(enemy)
            x += 110
        y += 30
    return enemies

def killEnemies(bullets, enemies):
    for bullet in bullets:
        for x in enemies:
            for y in x:
                if bullet.top <= y.bottom and bullet.top >= y.top:
                    if bullet.left >= y.left and bullet.right <= y.right:
                    x.remove(y)
                    bullets.remove(bullet)


def moveBullets(bullets):
    for bullet in bullets:
         bullet.top -= 15
    for b in bullets:
        pygame.draw.rect(DISPLAYSURF, white, b)

while True:


    if direction == 'left':
        shipx -= 8
        bulletx -= 8
    elif direction == 'right':
        shipx += 8
        bulletx += 8


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

        key = pygame.key.get_pressed()

        if key[K_LEFT]:
            direction = 'left'
        elif key[K_RIGHT]:
            direction = 'right'
        elif key[K_SPACE]:
            bullet = pygame.draw.line(DISPLAYSURF, white, (bulletx, bullety), (bulletx, bullety - 25), 2)
            bullets.append(bullet)

        if event.type == KEYUP:
            direction = ''

    time += timer        
    DISPLAYSURF.fill(black)
    pygame.draw.polygon(DISPLAYSURF, white, ((shipx, shipy), (shipx + 25, shipy - 50), (shipx + 50, shipy)), 1)
    drawEnemies(enemies)
    moveBullets(bullets)
    killEnemies(bullets, enemies)
    pygame.display.update()
    fpsClock.tick(FPS)