请给我用python 写一个飞机大战的游戏代码 标好注释

当然，下面是用Python实现的飞机大战游戏代码，注释已经添加在代码中，用于解释代码的不同部分的含义和功能。

# 导入所需的模块
import pygame
import random

# 初始化pygame模块
pygame.init()

# 设置游戏窗口大小和标题
width, height = 640, 480
screen = pygame.display.set_mode((width, height))
pygame.display.set_caption("飞机大战")

# 加载背景图片和飞机图片
background = pygame.image.load("background.png").convert()
player = pygame.image.load("player.png").convert_alpha()
enemy = pygame.image.load("enemy.png").convert_alpha()

# 设置帧率和字体
clock = pygame.time.Clock()
font = pygame.font.SysFont("Arial", 24)

# 定义常量
player_speed = 5
enemy_speed = 3
bullet_speed = 7
bullet_interval = 250  # 子弹发射间隔时间（单位：毫秒）

# 定义游戏对象类
class GameObject:
    def __init__(self, x, y, image):
        self.x = x
        self.y = y
        self.image = image

    def draw(self):
        screen.blit(self.image, (self.x, self.y))

    def collide(self, other):
        x_distance = abs(self.x - other.x)
        y_distance = abs(self.y - other.y)
        if x_distance < (self.image.get_width() + other.image.get_width()) / 2 and y_distance < (self.image.get_height() + other.image.get_height()) / 2:
            return True
        else:
            return False

# 定义玩家类
class Player(GameObject):
    def move_left(self):
        if self.x > 0:
            self.x -= player_speed

    def move_right(self):
        if self.x < width - self.image.get_width():
            self.x += player_speed

    def shoot(self):
        bullet = Bullet(self.x + self.image.get_width() / 2, self.y)
        bullets.add(bullet)

# 定义敌机类
class Enemy(GameObject):
    def move(self):
        self.y += enemy_speed

    def out_of_screen(self):
        return self.y > height

# 定义子弹类
class Bullet(GameObject):
    def move(self):
        self.y -= bullet_speed

    def out_of_screen(self):
        return self.y < -self.image.get_height()

# 创建玩家对象和敌机对象的集合
player = Player(width / 2 - player.get_width() / 2, height - player.get_height(), player)
enemies = pygame.sprite.Group()
bullets = pygame.sprite.Group()

# 定义游戏主循环
while True:
    # 处理游戏事件
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            quit()
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                player.move_left()
            elif event.key == pygame.K_RIGHT:
                player.move_right()
            elif event.key == pygame.K_SPACE:
                player.shoot()

    # 更新游戏对象状态
    for enemy in enemies:
        enemy.move()
        if enemy.out_of_screen():
            enemies.remove(enemy)
    for bullet in bullets:
        bullet.move()
        if bullet.out_of_screen():
            bullets.remove(bullet)

    # 判断游戏对象碰撞
    for enemy in enemies:
        if player.collide(enemy):
            pygame.quit()
            quit()
        for bullet in bullets:
            if bullet.collide(enemy):
                enemies.remove(enemy)
                bullets.remove(bullet)

    # 创建敌机
    if random.randint(1, 100) == 1:
        enemy = Enemy(random.randint(0, width - enemy.get_width()), -enemy.get_height(), enemy)
        enemies.add(enemy)

    # 绘制游戏画面
    screen.blit(background, (0, 0))
    player.draw()
    for enemy in enemies:
        enemy.draw()
    for bullet in bullets:
        bullet.draw()

    # 绘制游戏分数
    score_text = font.render("Score: " + str(len(bullets)), True, (255, 255, 255))
    screen.blit(score_text, (10, 10))

    # 更新游戏画面
    pygame.display.update()

    # 控制游戏帧率
    clock.tick(60)

以上是飞机大战游戏的Python实现代码，其中实现了玩家、敌机、子弹等游戏对象的定义和操作，以及游戏画面的绘制、碰撞检测等功能。需要注意的是，这只是一个简单的示例代码，实际的游戏代码需要更加复杂和完善。