学习于Python编程从入门到实践（Eric Matthes 著）

整体目录：外星人入侵文件夹是打包后的不必在意

图片和音效都是网上下载的

音效下载网站：Free 游戏爆击中 Sound Effects Download - Pixabay

运行效果：可以上下左右移动，空格开火，空格或点击Play开始游戏，飞船碰到外星人或者外星人到达屏幕底部则失去一条命

下面是各个文件的内容

alien.py

import pygame
from pygame.sprite import Sprite


class Alien(Sprite):
    """表示单个外星人的类"""

    def __init__(self, ai_settings, screen):
        """初始化外星人并设置其起始位置"""
        super(Alien, self).__init__()
        self.screen = screen
        self.ai_settings = ai_settings

        # 加载外星人图像，并设置其rect属性
        # self.image = pygame.image.load('E:\\Project\\alien_invasion\\images\\alien.png')
        self.image = pygame.image.load('images/alien.png')
        self.image = pygame.transform.scale(self.image, (45, 45))
        self.rect = self.image.get_rect()

        # 每个外星人最初都在屏幕左上角附近
        self.rect.x = self.rect.width
        self.rect.y = self.rect.height

        # 存储外星人的准确位置
        self.x = float(self.rect.x)

    def blitme(self):
        """在指定位置绘制外星人"""
        self.screen.blit(self.image, self.rect)

    def check_edges(self):
        """如果外星人位于屏幕边缘，就返回True"""
        screen_rect = self.screen.get_rect()
        if self.rect.right >= screen_rect.right:
            return True
        elif self.rect.left <= 0:
            return True

    def update(self):
        """向左或向右移动外星人"""
        self.x += (self.ai_settings.alien_speed_factor *
                   self.ai_settings.fleet_direction)
        self.rect.x = self.x

alien_invasion.py

import pygame
from pygame.sprite import Group
from settings import Settings
from game_stats import GameStats
from ship import Ship
import game_functions as gf
from button import Button
from scoreboard import Scoreboard




def run_game():
    # 初始化游戏并创建一个屏幕对象
    # 初始化pygame、设置和屏幕对象
    pygame.init()
    ai_settings = Settings()
    screen = pygame.display.set_mode(
        (ai_settings.screen_width, ai_settings.screen_height)
    )

    # screen = pygame.display.set_mode((1200, 800))
    pygame.display.set_caption("Alien Invasion")

    # 创建一个用于存储游戏统计信息的实例,并创建记分牌
    stats = GameStats(ai_settings)
    sb = Scoreboard(ai_settings, screen, stats)

    # 创建一个飞船
    ship = Ship(ai_settings, screen)
    # 创建一个用于存储子弹的编组
    bullets = Group()
    # 创建一个外星人编组
    aliens = Group()

    # 创建外星人群
    gf.create_fleet(ai_settings, screen, ship, aliens)

    # 创建Play按钮
    play_button = Button(ai_settings, screen, "Play")


    # 开始游戏的主循环
    while True:

        gf.check_events(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets)

        if stats.game_active:
            ship.update()
            # 对每个bullet调用bullet.update()
            gf.update_bullets(ai_settings, screen, stats, sb, ship, aliens, bullets)
            gf.update_aliens(ai_settings, screen, stats, sb, ship, aliens, bullets)
            # 这个print用来检查是否真的删除子弹，保留此条代码会严重拖慢运行速度
            # print(len(bullets))

        gf.update_screen(ai_settings, screen, stats, sb, ship, aliens, bullets, play_button)


run_game()

bullet.py

import pygame
from pygame.sprite import Sprite

class Bullet(Sprite):
    """一个对飞船发射的子弹进行管理的类"""

    def __init__(self, ai_settings, screen, ship):
        """在飞船所处的位置创建一个子弹的对象"""
        super(Bullet, self).__init__() # Python2.7写法，也可写为下面这种
        # super().__init__()
        self.screen = screen

        # 在(0, 0)处创建一个表示子弹的矩形，再设置正确的位置
        self.rect = pygame.Rect(0, 0, ai_settings.bullet_width, ai_settings.bullet_height)
        self.rect.centerx = ship.rect.centerx
        self.rect.top = ship.rect.top

        # 存储用小数表示的子弹位置
        self.y = float(ship.rect.y)

        self.color = ai_settings.bullet_color
        self.speed_factor = ai_settings.bullet_speed_factor

    def update(self):
        """向上移动子弹"""
        # 更新表示子弹位置的小数值
        self.y -= self.speed_factor
        # 更新表示子弹的rect的位置
        self.rect.y = self.y

    def draw_bullet(self):
        """在屏幕上绘制子弹"""
        pygame.draw.rect(self.screen, self.color, self.rect)

button.py

import pygame.font

class Button():

    def __init__(self, ai_settings, screen, msg):
        """初始化按钮属性"""
        self.screen = screen
        self.screen_rect = screen.get_rect()

        # 设置按钮的尺寸和其他属性
        self.width, self.height = 200, 50
        self.button_color = (0, 255, 0)
        self.text_color = (255, 255, 255)
        self.font = pygame.font.SysFont(None, 48)

        # 创建按钮的rect属性，并使其居中
        self.rect = pygame.Rect(0, 0, self.width, self.height)
        self.rect.center = self.screen_rect.center

        # 按钮的标签只需要创建一次
        self.prep_msg(msg)

    def prep_msg(self, msg):
        """将msg渲染为图像，并使其在按钮上居中"""
        self.msg_image = self.font.render(msg, True, self.text_color,
                                          self.button_color)
        self.msg_image_rect = self.msg_image.get_rect()
        self.msg_image_rect.center = self.rect.center

    def draw_button(self):
        # 绘制一个用颜色填充的按钮，再绘制文本
        self.screen.fill(self.button_color, self.rect)
        self.screen.blit(self.msg_image, self.msg_image_rect)

game_function.py

import sys
import pygame
# 设置 mixer 支持 MP3 格式
pygame.mixer.pre_init(44100, -16, 2, 2048)  # 44100是采样率，-16是采样位数，2是声道数，2048是缓冲区大小
pygame.init()
pygame.mixer.init()

from bullet import Bullet
from alien import Alien
from time import sleep

# 加载音效
# fire_sound = pygame.mixer.Sound('E:\Project\\alien_invasion\\sounds\\fire.mp3')
fire_sound = pygame.mixer.Sound('sounds/fire.mp3')
# hit_sound = pygame.mixer.Sound('E:\Project\\alien_invasion\\sounds\\hit.mp3')
hit_sound = pygame.mixer.Sound('sounds/hit.mp3')
hit_sound.set_volume(0.2)


def check_keydown_events(event, ai_settings, screen, stats, sb, ship, aliens, bullets):
    """响应按键"""
    if event.key == pygame.K_RIGHT:
        # 向右移动飞船
        ship.moving_right = True
    elif event.key == pygame.K_LEFT:
        # 向左移动飞船
        ship.moving_left = True
    elif event.key == pygame.K_UP:
        # 向上移动飞船
        ship.moving_up = True
    elif event.key == pygame.K_DOWN:
        # 向下移动飞船
        ship.moving_down = True
    elif event.key == pygame.K_SPACE:
        # 创建一颗子弹，并将其加入到编组bullets中
        if stats.game_active:
            fire_bullet(ai_settings, screen, ship, bullets)
        else:
            start_game(ai_settings, screen, stats, sb, ship, aliens, bullets)


    elif event.key == pygame.K_ESCAPE:
        sys.exit()


def fire_bullet(ai_settings, screen, ship, bullets):
    """如果还没有到达限制就发射一颗子弹"""
    if len(bullets) < ai_settings.bullets_allowed:
        new_bullet = Bullet(ai_settings, screen, ship)
        fire_sound.play()
        bullets.add(new_bullet)

def check_keyup_events(event, ship):
    """松开按键"""
    if event.key == pygame.K_RIGHT:
        ship.moving_right = False
    elif event.key == pygame.K_LEFT:
        ship.moving_left = False
    elif event.key == pygame.K_UP:
        ship.moving_up = False
    elif event.key == pygame.K_DOWN:
        ship.moving_down = False

def check_events(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets):
    """响应按键和鼠标事件"""
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()

        elif event.type == pygame.KEYDOWN:
            check_keydown_events(event, ai_settings, screen, stats, sb, ship, aliens, bullets)
        elif event.type == pygame.KEYUP:
            check_keyup_events(event, ship)
        elif event.type == pygame.MOUSEBUTTONDOWN:
            mouse_x, mouse_y = pygame.mouse.get_pos()
            check_play_button(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets, mouse_x, mouse_y)

def check_play_button(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets,
                      mouse_x, mouse_y):
    """再玩家单机Play按钮时开始游戏"""
    button_clicked = play_button.rect.collidepoint(mouse_x, mouse_y)
    if button_clicked and not stats.game_active:
        # 重制游戏设置
        ai_settings.initialize_dynamic_settings()

        start_game(ai_settings, screen, stats, sb, ship, aliens, bullets)


def start_game(ai_settings, screen, stats, sb, ship, aliens, bullets):
    # 隐藏光标
    pygame.mouse.set_visible(False)
    # 重置游戏统计信息
    stats.reset_stats()
    stats.game_active = True

    # 重置记分牌图像
    sb.prep_score()
    sb.prep_high_score()
    sb.prep_level()
    sb.prep_ships()

    # 清空外星人列表和子弹列表
    aliens.empty()
    bullets.empty()

    # 创建一群新的外星人，并让飞船居中
    create_fleet(ai_settings, screen, ship, aliens)
    ship.center_ship()



def update_screen(ai_settings, screen, stats, sb, ship, aliens, bullets, play_button):
    """更新屏幕上的图像，并切换到新屏幕"""
    # 每次循环时都重绘屏幕
    screen.fill(ai_settings.bg_color)
    # 在飞船和外星人后面重绘所有子弹
    for bullet in bullets.sprites():
        bullet.draw_bullet()
    ship.blitme()
    aliens.draw(screen)

    # 显示得分
    sb.show_score()

    # 如果游戏处于非活跃状态，就绘制Play按钮
    if not stats.game_active:
        play_button.draw_button()

    # 让最近绘制的屏幕可见
    pygame.display.flip()

def update_bullets(ai_settings, screen, stats, sb, ship, aliens, bullets):
    """更新子弹的位置，并删除已消失的子弹"""

    # 更新子弹位置
    bullets.update()

    # 删除已经消失的子弹
    for bullet in bullets.copy():
        if bullet.rect.bottom <= 0:
            bullets.remove(bullet)

    check_bullet_alien_collision(ai_settings, screen, stats, sb, ship, aliens, bullets)

def check_bullet_alien_collision(ai_settings, screen, stats, sb, ship, aliens, bullets):
    """响应子弹和外星人的碰撞"""
    # 删除发生碰撞子弹和外星人
    # 若第一个True变为False可以让子弹直到顶部才消失并删除所有击中的外星人反之只击中一个子弹也消失
    collisions = pygame.sprite.groupcollide(bullets, aliens, True, True)

    if collisions:
        for aliens in collisions.values():
            stats.score += ai_settings.alien_points * len(aliens)
            sb.prep_score()
            # 播放音效
            hit_sound.play()
        check_high_score(stats, sb)


    # 检查外星人存在情况
    if len(aliens) == 0:
        # 删除现有的子弹，加快节奏，并重新创建一群外星人
        bullets.empty()
        ai_settings.increase_speed()

        # 提高等级
        stats.level += 1
        sb.prep_level()

        create_fleet(ai_settings, screen, ship, aliens)

def get_number_alien_x(ai_settings, alien_width):
    """计算一行可以有多少个外星人"""
    available_space_x = ai_settings.screen_width - 2 * alien_width
    number_aliens_x = int(available_space_x / (2 * alien_width))
    return number_aliens_x

def get_number_rows(ai_settings, ship_height, alien_height):
    """计算屏幕可以有多少行外星人"""
    available_space_y = (ai_settings.screen_height -
                         (3 * alien_height) - ship_height)
    number_rows = int(available_space_y / (3 * alien_height))
    return number_rows

def create_alien(ai_settings, screen, aliens, alien_number, row_number):
    """创建一个外星人并将其放在当前行"""
    alien = Alien(ai_settings, screen)
    alien_width = alien.rect.width
    alien.x = alien_width + 2 * alien_width * alien_number
    alien.rect.x = alien.x
    alien.rect.y = alien.rect.height + 2 * alien.rect.height * row_number
    aliens.add(alien)

def create_fleet(ai_settings, screen, ship, aliens):
    """创建外星人群"""
    # 创建一个外星人，并计算一行可以容纳多少个外星人
    # 外星人之间的间距为外星人宽度
    alien = Alien(ai_settings, screen)
    number_aliens_x = get_number_alien_x(ai_settings, alien.rect.width)
    number_rows = get_number_rows(ai_settings, ship.rect.height, alien.rect.height)

    # 创建外星人群
    for row_number in range(number_rows):
        for alien_number in range(number_aliens_x):
            create_alien(ai_settings, screen, aliens, alien_number, row_number)

def check_fleet_edges(ai_settings, aliens):
    """有外星人到达边缘时采取相应的措施"""
    for alien in aliens.sprites():
        if alien.check_edges():
            change_fleet_direction(ai_settings, aliens)
            break

def change_fleet_direction(ai_settings, aliens):
    """将整个外星人下移， 并改变它们的方向"""
    for alien in aliens.sprites():
        alien.rect.y += ai_settings.fleet_drop_speed
    ai_settings.fleet_direction *= -1

def ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets):
    """响应被外星人撞到的飞船"""

    if stats.ships_left > 0:
        # 将ships_left减 1
        stats.ships_left -= 1

        # 更新记分牌
        sb.prep_ships()

        # 清空外星人列表和子弹列表
        aliens.empty()
        bullets.empty()

        # 创建一群新的外星人，并将飞船放到屏幕底端中央
        create_fleet(ai_settings, screen, ship, aliens)
        ship.center_ship()

        # 暂停
        sleep(0.5)
    else:
        stats.game_active = False
        pygame.mouse.set_visible(True)



def check_aliens_bottom(ai_settings, screen, stats, sb, ship, aliens, bullets):
    """检查是否有外星人到达屏幕底端"""
    screen_rect = screen.get_rect()
    for alien in aliens.sprites():
        if alien.rect.bottom >= screen_rect.bottom:
            # 像飞船被撞一样处理
            ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets)
            break

def update_aliens(ai_settings, screen, stats, sb, ship, aliens, bullets):
    """
    检查是否有外星人位于屏幕边缘，并更新整群外星人的位置
    """
    check_fleet_edges(ai_settings, aliens)
    aliens.update()

    # 检查是否有外星人到达底部
    check_aliens_bottom(ai_settings, screen, stats, sb, ship, aliens, bullets)

    # 检查外星人和飞船之间的碰撞
    if pygame.sprite.spritecollideany(ship, aliens):
        ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets)

def check_high_score(stats, sb):
    """检查是否诞生了新的最高分数"""
    if stats.score > stats.high_score:
        stats.high_score = stats.score
        sb.prep_high_score()

game_stats.py

class GameStats():
    """跟踪游戏的统计信息"""

    def __init__(self, ai_settings):
        """初始化统计信息"""
        self.ai_settings = ai_settings
        self.reset_stats()
        # 游戏刚启动时处于非活动状态
        self.game_active = False
        # 在任何情况下都不应重置最高分
        self.high_score = 0

    def reset_stats(self):
        """初始化在游戏运行期间可能变化的统计信息"""
        self.ships_left = self.ai_settings.ship_limit
        self.score = 0
        self.level = 1

scoreboard.py

import pygame.font
from pygame.sprite import Group

from ship import Ship

class Scoreboard():
    """显示得分信息类"""

    def __init__(self, ai_settings, screen, stats):
        """初始化显示得分涉及的属性"""
        self.screen = screen
        self.screen_rect = screen.get_rect()
        self.ai_settings = ai_settings
        self.stats = stats

        # 显示得分信息时使用的字体设置
        self.text_color = (30, 30, 30)
        self.font = pygame.font.SysFont(None, 48)

        # 准备包含最高分图像和当前得分图像
        self.prep_score()
        self.prep_high_score()
        self.prep_level()
        self.prep_ships()

    def prep_score(self):
        """将得分转换为一幅渲染的图像"""
        rounded_score = int(round(self.stats.score, -1))
        score_str = "{:,}".format(rounded_score)
        self.score_image = self.font.render(score_str, True, self.text_color,
                                            self.ai_settings.bg_color)

        # 将得分放在屏幕的右上角
        self.score_rect = self.score_image.get_rect()
        self.score_rect.right = self.screen_rect.right - 20
        self.score_rect.top = 5

    def show_score(self):
        """在屏幕中显示飞船和得分"""
        self.screen.blit(self.score_image, self.score_rect)
        self.screen.blit(self.high_score_image, self.high_score_rect)
        self.screen.blit(self.level_image, self.level_rect)
        # 绘制飞船
        self.ships.draw(self.screen)

    def prep_high_score(self):
        """将最高得分转换为渲染的图像"""
        high_score = int(round(self.stats.high_score, -1))
        high_score_str = "{:,}".format(high_score)
        self.high_score_image = self.font.render(high_score_str, True,
                                                 self.text_color, self.ai_settings.bg_color)

        # 将最高得分放在屏幕顶部中央
        self.high_score_rect = self.high_score_image.get_rect()
        self.high_score_rect.centerx = self.screen_rect.centerx
        self.high_score_rect.top = self.score_rect.top

    def prep_level(self):
        """将等级转换为渲染的图像"""
        self.level_image = self.font.render(str(self.stats.level), True,
                                            self.text_color, self.ai_settings.bg_color)

        # 将等级放在得下面
        self.level_rect = self.level_image.get_rect()
        self.level_rect.right = self.score_rect.right
        self.level_rect.top = self.score_rect.bottom + 10

    def prep_ships(self):
        """显示还剩余多少搜飞船"""
        self.ships = Group()
        for ship_number in range(self.stats.ships_left):
            ship = Ship(self.ai_settings, self.screen)
            ship.rect.x = 10 + ship_number * ship.rect.width
            ship.rect.y = 10
            self.ships.add(ship)

settings.py

class Settings():
    """存储《外星人入侵》的所有设置类"""

    def __init__(self):
        """初始化游戏静态设置"""
        # 屏幕设置
        self.screen_width = 1200
        self.screen_height = 800
        self.bg_color = (230, 230, 230)

        # 飞船的设置
        self.ship_speed_factor = 1.5
        self.ship_limit = 3

        # 子弹设置
        # self.bullet_speed_factor = 3
        self.bullet_width = 30
        self.bullet_height = 15
        self.bullet_color = 60, 60, 60
        self.bullets_allowed = 3

        # 外星人设置
        self.alien_speed_factor = 1
        # fleet_drop_speed表示触碰到屏幕边缘时下移的速度
        self.fleet_drop_speed = 5
        # fleet_direction为 1 表示向右移动，为 -1 表示向左移动
        self.fleet_direction = 1

        # 以什么样的速度加快游戏节奏
        self.speedup_scale = 1.1
        # 外星人点数提高速度
        self.score_scale = 1.5


        self.initialize_dynamic_settings()

    def initialize_dynamic_settings(self):
        """初始化随游戏进行而变化的设置"""
        self.ship_speed_factor = 1.5
        self.bullet_speed_factor = 3
        self.alien_speed_factor = 1

        # fleet_direction为 1 表示向右移动，为 -1 表示向左移动
        self.fleet_direction = 1

        # 记分
        self.alien_points = 50

    def increase_speed(self):
        """提高速度设置和外星人点数设置"""
        self.ship_speed_factor *= self.speedup_scale
        self.bullet_speed_factor *= self.speedup_scale
        self.alien_speed_factor *= self.speedup_scale

        self.alien_points = int(self.alien_points * self.score_scale)

ship.py

import pygame
from pygame.sprite import Sprite

class Ship(Sprite):

    def __init__(self, ai_settings, screen):
        """初始化飞船并设置其初始位置"""
        super(Ship, self).__init__()
        self.screen = screen
        self.ai_settings = ai_settings

        # 加载飞船图像并获取其外接矩形
        # self.image = pygame.image.load('E:\\Project\\alien_invasion\\images\\ship.bmp')
        self.image = pygame.image.load('images/ship.bmp')
        # 调整图片大小
        self.image = pygame.transform.scale(self.image, (35, 35))
        self.rect = self.image.get_rect()
        self.screen_rect = screen.get_rect()

        # 将每艘新飞船放在屏幕的底部中央
        self.rect.centerx = self.screen_rect.centerx
        self.rect.bottom = self.screen_rect.bottom

        # 在飞船的属性center中存储小数值
        self.centerx = float(self.rect.centerx)
        self.centery = float(self.rect.centery)

        # 移动标志
        self.moving_right = False
        self.moving_left = False
        self.moving_up = False
        self.moving_down = False

    def update(self):
        """根据移动标志的调整飞船的位置"""
        # 更新飞船的center值，而不是rect
        if self.moving_right and self.rect.right < self.screen_rect.right:
            # self.rect.centerx += 1
            self.centerx += self.ai_settings.ship_speed_factor
        if self.moving_left and self.rect.left > 0:
            # self.rect.centerx -= 1
            self.centerx -= self.ai_settings.ship_speed_factor

        if self.moving_up and self.rect.top > 0:
            self.centery -= self.ai_settings.ship_speed_factor
        if self.moving_down and self.rect.bottom < self.screen_rect.bottom:
            self.centery += self.ai_settings.ship_speed_factor

        # 根据self.center更新rect对象
        self.rect.centerx = self.centerx
        self.rect.centery = self.centery


    def blitme(self):
        """在指定位置绘制飞船"""
        self.screen.blit(self.image, self.rect)

    def center_ship(self):
        """让飞船在屏幕上居中"""
        # self.centerx = self.screen_rect.centerx
        self.centerx = self.screen_rect.centerx
        self.centery = self.screen_rect.bottom - 15