此项目在学习Python的过程中，对照着书本所写，已成功运行。

所用的编辑器为Spyder，安装插件Pygame.   外星人及飞船图片下载链接

以下为小部分代码，完整版已上传资源。

主程序：alien_invasion.py

import sys

import pygame

from pygame.sprite import Group

from settings import Settings

from game_stats import GameStats

from scoreboard import Scoreboard

from button import Button

from ship import Ship

from alien import Alien

import game_functions as gf

def run_game():

# 初始化游戏并创建一个屏幕对象

pygame.init()

ai_settings=Settings()

screen=pygame.display.set_mode(

(ai_settings.screen_width,ai_settings.screen_height))

pygame.display.set_caption("Alien Invasion")

# 创建play按钮

play_button=Button(ai_settings,screen,"Play")

# 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)

# 创建一艘飞船,创建一个用于存储子弹的编组，创建一个外星人编组

ship=Ship(ai_settings,screen)

bullets=Group()

aliens=Group()

# 创建外星人群

gf.create_fleet(ai_settings,screen,ship,aliens)

#开始游戏主循环

while True:

# 从gf中调用函数鼠标键盘，

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

# 更新飞船位置

if stats.game_active:

ship.update()

# 更新屏幕

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

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

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

run_game()

储存大量游戏运行的函数 :game_functions.py

import sys

from time import sleep

import pygame

from bullet import Bullet

from alien import Alien

def check_keydown_events(event,ai_settings,screen,ship,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:

ship.moving_left=True

elif event.key==pygame.K_SPACE:

fire_bullet(ai_settings,screen,ship,bullets)

# 快捷键结束游戏

elif event.key == pygame.K_q:

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"""

# 创建一颗子弹并将其加入到编组bullets中,屏幕上最多有三颗子弹

if len(bullets) < ai_settings.bullets_allowed:

new_bullet=Bullet(ai_settings,screen,ship)

bullets.add(new_bullet)

def check_keyup_events(event,ship):

"""响应松开"""

if event.key==pygame.K_RIGHT:

ship.moving_right=False

elif event.key==pygame.K_LEFT:

ship.moving_left=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()

# 按下鼠标

elif event.type==pygame.KEYDOWN:

check_keydown_events(event,ai_settings,screen,ship,bullets)

# 松开鼠标

elif event.type==pygame.KEYUP:

check_keyup_events(event,ship)

# 点击开始Play

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):

"""在玩家单击play时开始新游戏"""

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更新"""

# 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()

# 让最近绘画的屏幕可见

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"""

# 更新子弹的位置

bullets.update()

# 删除已消失的子弹

for bullet in bullets.copy():

if bullet.rect.bottom <= 0:

bullets.remove(bullet)

check_bullet_alien_collisions(ai_settings,screen,stats,sb,

ship,aliens,bullets)

def check_bullet_alien_collisions(ai_settings,screen,stats,sb,

ship,aliens,bullets):

"""响应子弹和外星人的碰撞"""

# 删除发生碰撞的子弹和外星人

# 方法groupcollide将子弹和外星人的rect相比较

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()

check_high_score(stats,sb)

if len(aliens) == 0:

# 删除现有的子弹加快游戏节奏，并新建一群外星人,整群外星人被消灭，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)

def get_number_aliens_x(ai_settings,alien_width):

"""计算每行可容纳多少个外星人"""

available_space_x=ai_settings.screen_width - 2 * alien_width

number_alien_x=int(available_space_x / (2 * alien_width))

return number_alien_x

def get_number_rows(ai_settings,ship_height,alien_height):

"""计算屏幕可容纳多少行外星人"""

available_space_y=(ai_settings.screen_height -

(3 * alien_height) - ship_height)

number_rows=int(available_space_y / (2 * 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

# 外星人间距为外星人宽度

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)

# 创建第一行外星人

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):

"""将整群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 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()

# 检测外星人和飞船之间的碰撞方法检测

if pygame.sprite.spritecollideany(ship,aliens):

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

# 检查是否有外星人到达屏幕底部

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

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，并将飞船放在屏幕底部中央

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):

"""检查是否有外星人达到屏幕底部"""

screen_rect=screen.get_rect()

for alien in aliens.sprites():

if alien.rect.bottom >= screen_rect.bottom:

# 像飞船被撞到一样进行处理

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

break

def check_high_score(stats,sb):

"""检查对否诞生了新的最高得分"""

if stats.score > stats.high_score:

stats.high_score=stats.score

sb.prep_high_score()

在运行的过程中，注意函数参数的位置