前言

代码来源《python编程从入门到实践》Eric Matthes 署 袁国忠 译

使用软件：PyCharm Community Editor 2022

目的：记录一下按照书上敲的代码

alien_invasion.py

游戏的一些初始化设置，调用已经封装好的函数方法，一个函数的调用实现一个游戏的部分。

import pygame from settings import Settings from ship import Ship import game_functions as gf from pygame.sprite import Group from game_stats import GameStats 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     pygame.init()     ai_settigns = Settings()     # 里面是一个元组     screen = pygame.display.set_mode((ai_settigns.screen_width, ai_settigns.screen_height))     # 窗口尺寸，宽高     # screen=pygame.display.set_mode((1200,800))     # 窗口标题     pygame.display.set_caption("Alien Invasion")     # 创建Play按钮     play_button = Button(ai_settigns, screen, "Play")     # 创建一个用于存储游戏统计信息的实例     stats = GameStats(ai_settigns)     # 创建储存游戏统计信息的实例，并创建记分牌     sb = Scoreboard(ai_settigns, screen, stats)      # 设置背景色     # bg_color=(230,230,230)     # 创建一艘飞船、一个子弹编组和一个外星人编组     ship = Ship(ai_settigns, screen)     # 创建一个用于存储子弹的编组     bullets = Group()     # 创建一个外星人     # alien=Alien(ai_settigns,screen)     aliens = Group()     # 创建外星人群     gf.create_fleet(ai_settigns, screen, ship, aliens)      # 开始游戏的主循环     while True:         gf.check_events(ai_settigns, screen, stats, sb, play_button, ship, aliens, bullets)         if stats.game_active:             ship.update()             gf.update_bullets(ai_settigns, screen, stats, sb, ship, aliens, bullets)             gf.update_aliens(ai_settigns, screen, stats, sb, ship, aliens, bullets)         # print(len(bullets))          gf.update_screen(ai_settigns, screen, stats, sb, ship, aliens, bullets, play_button)         # 监视键盘和鼠标事件         # for event in pygame.event.get():         #     if event.type==pygame.QUIT:         #         sys.exit()         # 每次循环都重绘屏幕         # screen.fill(bg_color)         # screen.fill(ai_settigns.gb_color)         # ship.blitme()         # 让最近绘制的屏幕可见         # pygame.display.flip()   run_game() 

game_functions.py

 游戏主体，具体功能的实现被封装在里面，按下按键、松开按键的响应，界面的更新、子弹的发射、外星人和飞船之间碰撞的检查等等。

import sys import pygame from bullet import Bullet from alien import Alien from time import sleep   # 响应按键 def check_keydown_events(event, ai_settings, screen, ship, bullets):     if event.key == pygame.K_RIGHT:         ship.moving_right = True     elif event.key == pygame.K_LEFT:         ship.moving_left = True     elif event.key == pygame.K_SPACE:         fire_bullet(ai_settings, screen, ship, bullets)     # 按下键盘上的q键同样关闭游戏界面(需要是英文状态下)     elif event.key == pygame.K_q:         sys.exit()   # 响应松开 def check_keyup_events(event, ship):     if event.key == pygame.K_RIGHT:         ship.moving_right = False     elif event.key == pygame.K_LEFT:         ship.moving_left = False   # 响应按键和鼠标事件 def check_events(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets):     for event in pygame.event.get():         if event.type == pygame.QUIT:             sys.exit()          elif event.type == pygame.KEYDOWN:             # if event.key == pygame.K_RIGHT:             #     ship.moving_right = True             # elif event.key == pygame.K_LEFT:             #     ship.moving_left = True             check_keydown_events(event, ai_settings, screen, ship, bullets)         elif event.type == pygame.KEYUP:             # if event.key == pygame.K_RIGHT:             #     ship.moving_right = False             # elif event.key == pygame.K_LEFT:             #     ship.moving_left = False             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)   # 更新屏幕上的图像，并切换到新屏幕 def update_screen(ai_settings, screen, stats, sb, ship, aliens, bullets, play_button):     # 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()     # 如果游戏处于非活动状态，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()   # 更新子弹的位置，并删除已经消失的子弹 def update_bullets(ai_settings, screen, stats, sb, ship, aliens, bullets):     # 更新子弹的位置     bullets.update()      # 删除已经消失的子弹     for bullet in bullets.copy():         if bullet.rect.bottom <= 0:             bullets.remove(bullet)      # 检查是否有子弹击中了外星人     # 如果是这样，就删除相应的子弹和外星人     check_bullet_alien_collision(ai_settings, screen, stats, sb, ship, aliens, bullets)   # 响应子弹和外星人的碰撞 def check_bullet_alien_collision(ai_settings, screen, stats, sb, ship, aliens, bullets):     # 删除发生碰撞的子弹和外星人     collisions = pygame.sprite.groupcollide(bullets, aliens, True, True)     if collisions:         for aliens in collisions.values():             stats.score += ai_settings.alien_points             sb.prep_score()         check_high_score(stats, sb)      if len(aliens) == 0:         # 删除现有的子弹并新建一群外星人(如果整群外星人都被消灭，就提高一个等级)         bullets.empty()         ai_settings.increase_speed()         # 提高等级         stats.level += 1         sb.prep_level()          create_fleet(ai_settings, screen, ship, aliens)   # 如果还没有到达限制，就发射一颗子弹 def fire_bullet(ai_settings, screen, ship, bullets):     # 创建一颗子弹,并将其加入到编组bullets中     if len(bullets) < ai_settings.bullets_allowed:         new_bullet = Bullet(ai_settings, screen, ship)         bullets.add(new_bullet)   # 创建一个外星人群 def create_fleet(ai_settings, screen, ship, aliens):     # 创建一个外星人，并计算每行可容纳多少个外星人     alien = Alien(ai_settings, screen)     number_aliens_x = get_number_aliens_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):             # 创建一个外星人并将其加入当前行             create_alien(ai_settings, screen, aliens, alien_number, row_number)   # 计算每行可容纳多少个外星人 def get_number_aliens_x(ai_settings, alien_width):     available_space_x = ai_settings.screen_width - 2 * alien_width     number_aliens_x = int(available_space_x / (2 * alien_width))     return number_aliens_x   # 创建一个外星人并将其放在当前行 def create_alien(ai_settings, screen, aliens, alien_number, row_number):     # 外星人间距为外星人的宽度     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)   # 计算屏幕可容纳多少行外星人 def get_number_rows(ai_settings, ship_height, alien_height):     available_space_y = (ai_settings.screen_height - (3 * alien_height) - ship_height)     number_rows = int(available_space_y / (2 * alien_height))     return number_rows   # 检查是否有外星人位于屏幕边缘，更新外星人群中所有外星人的位置 def update_aliens(ai_settings, screen, stats, sb, ship, aliens, bullets):     check_fleet_edges(ai_settings, aliens)     aliens.update()      # 检测外星人和飞船之间的碰撞     if pygame.sprite.spritecollideany(ship, aliens):         # print("Ship hit!!!")         ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets)      # 检查是否有外星人到达屏幕底端     check_aliens_bottom(ai_settings, screen, stats, sb, ship, aliens, bullets)   # 有外星人到达边缘采取相应的措施 def check_fleet_edges(ai_settings, aliens):     for alien in aliens.sprites():         if alien.check_edges():             change_fleet_direction(ai_settings, aliens)             break   # 将整群外星人下移，并改变他们的方向 def change_fleet_direction(ai_settings, aliens):     for alien in aliens.sprites():         alien.rect.y += ai_settings.fleet_drop_speed     ai_settings.fleet_direction *= -1   # 响应被外星人撞到的飞船 def ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets):     if stats.ships_left > 0:         # 将ships_letf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)   # 检查是否有外星人到达了屏幕底端 def check_aliens_bottom(ai_settings, screen, stats, sb, ship, aliens, bullets):     screen_rect = screen.get_rect()     for alien in aliens.sprites():         if alien.rect.bottom >= screen_rect.bottom:             # 向飞船被撞到一样进行处理             ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets)             break   # 在玩家单机Play按钮时开始新游戏 def check_play_button(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets, mouse_x, mouse_y):     button_clicked = play_button.rect.collidepoint(mouse_x, mouse_y)     if button_clicked and not stats.game_active:         # 重置游戏设置         ai_settings.initialize_dynamic_settings()         # 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()   # 检查是否诞生了新的最高部分 def check_high_score(stats, sb):     if stats.score > stats.high_score:         stats.high_score = stats.score         sb.prep_high_score() 

settings.py

游戏的一些初始化数据的储存，子弹的速度，大小，屏幕的大小等等。

# 储存《外星人入侵》所设置的类 class Settings():     # 初始化游戏的静态属性     def __init__(self):         # 屏幕设置         self.screen_width = 1200         self.screen_height = 800         self.bg_color = (230, 230, 230)          # 飞船设置         # 位置         self.ship_speed_factor = 1.5         self.ship_limit = 3          # 子弹设置(宽高，颜色)         self.bullet_speed_factor = 1  # 速度         self.bullet_width = 3  # 宽度         self.bullet_height = 15  # 高度         self.bullet_color = 60, 60, 60  # 颜色         self.bullets_allowed = 3          # 外星人设置         self.alien_speed_factor = 1         self.fleet_drop_speed = 10         # fleet_direction为1表示向右移，为-1表示向左移         self.fleet_direction = 1          # 以什么样的速度加快游戏节奏         self.speedup_scale = 1.1         # 外星人点数的提高速度         self.score_scale = 1.5         self.initialize_dynamic_settings()          # 记分         self.alien_points = 50      # 初始化随游戏进行而变化的设置     def initialize_dynamic_settings(self):         self.ship_speed_factor = 1.5         self.bullet_speed_factor = 3         self.alien_speed_factor = 1          # fleet_direction为1表示向右；为-1表示向左         self.fleet_direction = 1      # 提高速度和外星人点数设置     def increase_speed(self):         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)         print(self.alien_points) 

ship.py

 飞船的初始化信息（在屏幕上面显示的位置）和移动。

import pygame from pygame.sprite import Sprite  class Ship(Sprite):     # 初始化飞船并设置其初始位置     def __init__(self, ai_settings, screen):         super(Ship, self).__init__()         self.screen = screen         self.ai_settings = ai_settings         # 加载飞船图像并获取外接矩形         self.image = pygame.image.load('images/ship.png')         self.rect = self.image.get_rect()         self.screen_rect = screen.get_rect()         # 将每艘新飞船放在屏幕底部中央         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.center = float(self.rect.centerx)          # 移动标志         self.moving_right = False         self.moving_left = False      # 根据移动标志调整飞船的位置     def update(self):         # 更新飞船的center值，而不是rect         # if self.moving_right:         # 增加不能越界的条件         if self.moving_right and self.rect.right < self.screen_rect.right:             # self.rect.centerx += 1             self.center += self.ai_settings.ship_speed_factor         # elif self.moving_left:         if self.moving_left and self.rect.left > 0:             # self.rect.centerx -= 1             self.center -= self.ai_settings.ship_speed_factor          # 根据self.center更新rect对象         self.rect.centerx = self.center      # 在指定位置绘制飞船     def blitme(self):         self.screen.blit(self.image, self.rect)      # 让飞船在屏幕上居中     def center_ship(self):         self.center = self.screen_rect.centerx 

alien.py

外星人的初始信息（在屏幕上面显示的位置）和移动。

import pygame from pygame.sprite import Sprite   # 表示单个外星人的类 class Alien(Sprite):     # 初始化外星人并设置起始位置     def __init__(self, ai_settings, screen):         super(Alien, self).__init__()         self.screen = screen         self.ai_settins = ai_settings          # 加载外星人图像，并设置其rect属性         self.image = pygame.image.load('images/alien.png')         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)      # 在指定位置绘制外星人     def blitme(self):         self.screen.blit(self.image, self.rect)      # 向右、左移动外星人     def update(self):         # self.x += self.ai_settins.alien_speed_factor         self.x += (self.ai_settins.alien_speed_factor * self.ai_settins.fleet_direction)         self.rect.x = self.x      # 如果外星人位于屏幕边缘，就返回True     def check_edges(self):         screen_rect = self.screen.get_rect()         if self.rect.right >= screen_rect.right:             return True         elif self.rect.left <= 0:             return True 

bullet.py

子弹的显示和移动。

import pygame from pygame.sprite import Sprite   # 一个对飞船发射的子弹进行管理的类 class Bullet(Sprite):     # 在飞船所处的位置创建一个子弹对象     def __init__(self, ai_settings, screen, ship):         super(Bullet, self).__init__()         self.screen = screen          # 在(0,0)处创建一个表示子弹的矩形，在设置正确的位置         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(self.rect.y)         self.color = ai_settings.bullet_color         self.speed_factor = ai_settings.bullet_speed_factor      # 向上移动子弹     def update(self):         # 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      # 在屏幕上绘制子弹     def draw_bullet(self):         pygame.draw.rect(self.screen, self.color, self.rect) 

game_stats.py

游戏是否结束，统计游戏运行期间的变化。

# 跟踪游戏的统计信息 class GameStats():     # 初始化统计信息     def __init__(self, ai_settings):         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得分         self.high_score = 0      # 初始化在游戏运行期间可能变化的统计信息     def reset_stats(self):         self.ships_left = self.ai_settings.ship_limit         self.score = 0         self.level = 1 

 button.py

开始按钮

import pygame.font   class Button():     # 初始化按钮的属性     def __init__(self, ai_setting, screen, msg):         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, 0, 0)         self.text_color = (255, 255, 255)         self.font = pygame.font.SysFont(None, 48)          # 创建按钮的rect的对象，并使其居中         self.rect = pygame.Rect(0, 0, self.width, self.height)         self.rect.center = self.screen_rect.center          # 按钮的标签只需创建一次         self.prep_msg(msg)      # 将msg渲染为图像，并使其在按钮上居中     def prep_msg(self, msg):         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      # 绘制一个用颜色填充的按钮，再绘制文本     def draw_button(self):         self.screen.fill(self.button_color, self.rect)         self.screen.blit(self.msg_image, self.msg_image_rect) 

scoreboard.py

当前得分，和最高得分

import pygame.font from pygame.sprite import Group from ship import Ship   # 显示得分信息的类 class Scoreboard():     def __init__(self, ai_setting, screen, stats):         self.screen = screen         self.screen_rect = screen.get_rect()         self.ai_setting = ai_setting         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)          # 准备初始得分图像         self.prep_score()         self.prep_high_score()         self.prep_level()         self.prep_ships()      # 将得分转换为一幅渲染的图像     def prep_score(self):         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_setting.bg_color)          # 将得分放在屏幕右上角         self.score_rect = self.score_image.get_rect()         self.score_rect.right = self.screen_rect.right - 20;         self.score_rect.top = 20      # 在屏幕上显示得分和飞船     def show_score(self):         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)      # 将最高得分转换为渲染的图像     def prep_high_score(self):         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_setting.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      # 将等级转换为渲染的图像     def prep_level(self):         self.level_image = self.font.render(str(self.stats.level), True, self.text_color, self.ai_setting.bg_color)          # 将等级放在得分下方         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      # 显示还余下多少艘飞船     def prep_ships(self):         self.ships = Group()         for ship_number in range(self.stats.ships_left):             ship = Ship(self.ai_setting, self.screen)             ship.rect.x = 10 + ship_number * ship.rect.width             ship.rect.y = 10             self.ships.add(ship) 

我们的飞船和下面的飞船相撞或者撞到下面的墙都会输出：“Ship hit!!!”(程序中已经注释)

 图片可以自己去找，如果想修改图片可以运用电脑的“画图”工具来实现。

总结

主要是记录一下这个，毕竟敲了这么久了，不过还是要理解。

整个游戏的结构还是是否清晰的，游戏的流程储存在alien_invasion中，为了让程序的可读性更好，把功能封装成对应的函数，把这些函数全部储存到game_functions中，把游戏需要初始化的数据（子弹的大小，颜色，速度等等）全部储存到settings中，ship是对飞船的抽象表示，alien是对外星人的抽象表示，bullet是对子弹的抽象表示，通过button来开始游戏，game_stats来记录整个游戏，用scoreboard统计游戏得分。