Python编程：从入门到实践 项目《外星人入侵》完整代码

学习《Python编程：从入门到实践》有段时间了，跟着书本把所有代码都敲了一遍，感悟很深，现在完成了《外星人入侵》项目，对于库、类、函数、方法都有一定的理解，现在将该项目完整代码分享出来，以供学习。

1.首先当然是主运行文件alien_invasion.py

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
import game_functions as gf

def run_game(): 
    # 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))
    pygame.display.set_caption("Alien Invasion")
    
    # 创建Play按钮
    play_button = Button(ai_settings, screen, "Play")
    
    # 创建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、一个子弹编组和一个外星人编组
    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()
            gf.update_bullets(ai_settings,screen,stats,sb,ship,aliens,
                bullets)
            gf.update_aliens(ai_settings,stats,screen,sb,ship,aliens,bullets)

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

run_game()

　　

2.游戏相关参数设置settings.py

class Settings(): 
    """存储《外星人入侵》的所有设置的类""" 
    def __init__(self): 
        """初始化游戏的静态设置""" 
        # 屏幕设置
        self.screen_width = 800 
        self.screen_height = 600 
        self.bg_color = (230, 230, 230)
        
        # 飞船的设置
        self.ship_speed_factor = 0.3
        
        #子弹设置
        self.bullet_speed_factor = 1
        self.ship_limit = 3
        self.bullet_width = 3
        self.bullet_height = 15
        self.bullet_color = 60,60,60
        self.bullets_allowed = 3

		# 外星人设置
        self.alien_speed_factor = 0.1
        self.fleet_drop_speed = 10
        
        # 以什么样的速度加快游戏节奏
        self.speedup_scale = 1.01
        # 外星人点数的提高速度
        self.score_scale = 1.1

        self.initialize_dynamic_settings()
        
		# fleet_direction为1表示向右移，为-1表示向左移
        self.fleet_direction = 1

    def initialize_dynamic_settings(self): 
        """初始化随游戏进行而变化的设置""" 
        self.ship_speed_factor = 0.3 
        self.bullet_speed_factor = 1 
        self.alien_speed_factor = 0.1
        
        # fleet_direction为1表示向右；为-1表示向左
        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""" 
        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)

　　

3.按键及事件逻辑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:
        ship.moving_right = True
    elif event.key == pygame.K_LEFT:
        ship.moving_left = True
    elif event.key == pygame.K_UP:
        ship.moving_up = True
    elif event.key == pygame.K_DOWN:
        ship.moving_down = True
    elif event.key == pygame.K_SPACE:
        fire_bullet(ai_settings,screen,ship,bullets)
    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
    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
    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,ship,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): 
    """在玩家单击Play按钮时开始新游戏"""
    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_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
    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:
        # 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) 

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()

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_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 / (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.y = alien.rect.height + 2 * alien.rect.height * row_number
	alien.rect.x = alien.x
	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): 
			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 ship_hit(ai_settings, stats, screen, 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, stats, screen, sb, ship, aliens, bullets): 
    """检查是否有外星人到达了屏幕底端""" 
    screen_rect = screen.get_rect() 
    for alien in aliens.sprites():
        if alien.rect.bottom >= screen_rect.bottom: 
            # 像飞船被撞到一样进行处理
            ship_hit(ai_settings, stats, screen, sb, ship, aliens, bullets) 
            break

def check_high_score(stats, sb): 
    """检查是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()

def update_aliens(ai_settings, stats, screen, 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
    if pygame.sprite.spritecollideany(ship, aliens):
        ship_hit(ai_settings, stats, screen, sb, ship, aliens, bullets)
    
    # 检查是否有外星人到达屏幕底端
    check_aliens_bottom(ai_settings, stats, screen, sb, ship, aliens, bullets)

　　

4.计分相关设置scoreboard.py

import pygame.font
from pygame.sprite import Group

from ship import Ship

class Scoreboard():
    """显示得分信息的类"""

    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)

        # 准备包含最高得分和当前得分的图像
        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 

    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

    def prep_ships(self): 
        """显示还余下多少艘飞船"""
        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) 

    def show_score(self): 
        """在屏幕上显示飞船和得分""" 
        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)

　　

5.跟踪游戏统计信息

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 
        
    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
        

　　

6.“游戏开始”按键设置button.py

import pygame.font

class Button():
    
    def __init__(self, ai_settings, screen, msg):
        """初始化按钮的属性"""
        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('arial', 48)
          
        # 创建按钮的rect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)

    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) 

　　

7.飞船相关设置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('images/ship.bmp')
        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)
        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.center += self.ai_settings.ship_speed_factor
        if self.moving_left and self.rect.left > 0:
            self.center -= 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.center
        self.rect.centery = self.centery

    def center_ship(self): 
        """让飞船在屏幕上居中""" 
        self.center = self.screen_rect.centerx
        self.centery = self.screen_rect.bottom
        
    def blitme(self):
        """在指定位置绘制飞船""" 
        self.screen.blit(self.image,self.rect) 

　　

8.外星人相关设置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('images/alien.bmp') 
        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): 
        """向左或右移动外星人""" 
        self.x += (self.ai_settings.alien_speed_factor * 
                    self.ai_settings.fleet_direction)
        self.rect.x = self.x 

　　

9.子弹相关设置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对象""" 
        super(Bullet, self).__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(self.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) 

　　

关于ship.py文件中
self.image = pygame.image.load(‘images/ship.bmp’)
和alien.py文件中
self.image = pygame.image.load(‘images/alien.bmp’)
代码里的图片，需要各位自行在根目录下新建文件夹和图像

另外，自己在调试项目的过程中，常常有报错，其中主要错误的反而是忘了下划线、冒号还有代码缩进，代码缩进要么完全使用空格，要么全都使用tab进行缩进，python在识别缩进上非常严格。

写给自己，也分享给大家。

原文：https://blog.csdn.net/kenidi8215/article/details/88862701