python游戏demo——外星人入侵

先上一张效果图

再来一张动图

代码如下（较多）
alien_invasion/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)
    )
    # screen = pygame.display.set_mode((1200,800))
    pygame.display.set_caption("外星人入侵")

    # 创建开始游戏按钮
    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)
    # 设置背景色
    bg_color = (230,230,230)

    # 创建一艘飞船
    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
    # alien = Alien(ai_settings, screen)
    # 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)

    # 开始游戏的主循环
    while True:

        # 监视键盘和鼠标事件
        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, screen, stats, sb, ship, aliens, bullets)

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

run_game()

alien_invasion/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该重置最高得分
        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

alien_invasion/scoreboard.py

import pygame.ftfont
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.ftfont.SysFont('arial', 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)) # python2
        rounded_score = round(self.stats.score, -1)
        score_str = "{:,}".format(rounded_score)
        # score_str = str(self.stats.score)
        self.score_image = self.font.render('Score ' + 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 = round(self.stats.high_score, -1)
        high_score_str = "{:,}".format(high_score)
        self.high_score_image =self.font.render('High Score ' + 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 show_score(self):
        """在屏幕上显示得分"""
        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_level(self):
        """将等级转换为渲染的图像"""
        self.level_image = self.font.render('Level ' + 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):
        """显示剩余飞船数"""
        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)

alien_invasion/button.py

import pygame.ftfont
import pygame.sysfont
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.ftfont._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)

alien_invasion/game_functions.py

import sys

import pygame

from bullet import Bullet
from alien import Alien

from time import sleep

def check_keydown_events(event, ai_settings, screen, ship, bullets):
    """响应按键"""
    if event.key == pygame.K_RIGHT:
        ship.moving_right = True
        # 向右移动飞船
        # ship.rect.centerx += 1
    elif event.key == pygame.K_LEFT:
        ship.moving_left = True
    elif event.key == pygame.K_SPACE:
        fire_bullet(ai_settings, screen, ship, bullets)
    elif event.key == pygame.K_q:
        sys.exit()

def check_keyup_events(event, ship):
    """响应松开"""
    if event.key == pygame.K_RIGHT:
        ship.moving_right = False
    if 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()
        elif event.type == pygame.KEYDOWN:
            check_keydown_events(event, ai_settings, screen, ship, bullets)
            # check_keydown_events(event, ship)
        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 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)
    # screen.fill(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)
    # alien.blitme()

    # 显示得分
    sb.show_score()

    # 如果游戏处于非活动状态，就绘制开始游戏按钮
    if not stats.game_active:
        play_button.draw_button()

    # 让最近的绘制屏幕可见
    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 fire_bullet(ai_settings, screen, ship, bullets):
    """如果还没有达到限制，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 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_space_x = get_number_aliens_x(ai_settings, alien.rect.width)
    number_rows = get_number_rows(ai_settings, ship.rect.height,
                                  alien.rect.height)
    for row_nunber in range(number_rows):
        # 创建第一行外星人
        for alien_number in range(number_space_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_nunber)
            # create_alien(ai_settings, screen, aliens ,alien_number)

def get_number_aliens_x(ai_settings ,alien_width):
    """计算每行可容纳多少外星人"""
    avaliable_sqpce_x = ai_settings.screen_width - 2 * alien_width
    number_space_x = int(avaliable_sqpce_x / (2 * alien_width))
    return number_space_x

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 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 update_aliens(ai_settings, screen, stats, sb, ship, aliens, bullets):
    """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"""
    check_fleet_edges(ai_settings, aliens)
    aliens.update()

    # 检测外星人和飞船相撞
    if pygame.sprite.spritecollideany(ship, aliens):
        ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets)
        # print("飞船遭遇撞击！！！")
    # 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)

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):
    """将外星人下移，并改变他们的方向"""
    for alien in aliens.sprites():
        alien.rect.y += ai_settings.fleet_drop_speed
    ai_settings.fleet_direction *= -1

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

    # 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
    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:
        # 如果整群外星人被消灭，就提高一个等级
        # 删除现有的子弹并创建一群新外星人
        bullets.empty()
        ai_settings.increase_speed()

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

        create_fleet(ai_settings, screen, ship, aliens)

def ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets):
    """响应被撞到的飞船"""
    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了底端"""
    screen_rect = screen.get_rect()
    for alien in aliens.sprites():
        if alien.rect.bottom >= screen_rect.bottom:
            # 像飞船被撞倒一样处理
            ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets)
            break

def check_play_button(ai_settings, screen, stats, sb, play_button, ship, aliens,
                      bullets, mouse_x, mouse_y):
    """在玩家单击开始游戏按钮时开始游戏"""
    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()

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

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()

alien_invasion/alien.py

import sys
import os.path
import pygame
from pygame.sprite import Sprite

def resource_path(relative_path):
    try:
        base_path = sys._MEIPASS
    except Exception:
        base_path = os.path.abspath(".")

    return os.path.join(base_path, relative_path)

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().__init__()
        self.screen = screen
        self.ai_settings = ai_settings

        # 加载外星人图像，并设置其rect性
        self.image = pygame.image.load(resource_path('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 update(self):
        """向右移动外星人"""
        self.x += (self.ai_settings.alien_speed_factor *
                   self.ai_settings.fleet_direction)
        # self.x += self.ai_settings.alien_speed_factor
        self.rect.x = self.x

    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

alien_invasion/ship.py

import sys
import os.path
import pygame
from pygame.sprite import Sprite

def resource_path(relative_path):
    try:
        base_path = sys._MEIPASS
    except Exception:
        base_path = os.path.abspath(".")

    return os.path.join(base_path, relative_path)

class Ship(Sprite):

    def __init__(self,ai_settings, screen):
        """初始化飞船并获取其初始位置"""
        super().__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(resource_path('ship.bmp'))
        self.rect = self.image.get_rect()
        self.screen_rect = screen.get_rect()

        # 将每艘飞船放在屏幕底中央
        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

    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:
        # if self.moving_right:
            self.center += self.ai_settings.ship_speed_factor
            # self.rect.centerx += 1
        if self.moving_left and self.rect.left > 0:
        # if self.moving_left:
            self.center -= self.ai_settings.ship_speed_factor
            # self.rect.centerx -= 1

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

    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.center = self.screen_rect.centerx

alien_invasion/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 = 1200
        self.screen_height = 800
        self.bg_color = (230,230,230)
        self.ship_limit = 3

        # 子弹设置
        self.bullet_width = 3
        self.bullet_height = 15
        self.bullet_color = 60,60,60
        self.bullets_allowed = 3
        # 外星人设置
        self.fleet_drop_speed = 10

        # 以什么样的速度加快游戏节奏
        self.speedup_scale = 1.2
        # 外星人点数的提高速度
        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
        self.alien_points = 50

        # fleet_direction 为1表示右移，-1表示左移
        self.fleet_direction = 1

    def increase_speed(self):
        """提高速度设置"""
        self.ship_speed_factor *= self.speedup_scale
        self.bullet_speed_factor *= self.speedup_scale
        self.alien_speed_factor *= self.speedup_scale

        # 提高点数外星人
        self.alien_points = int(self.alien_points * self.score_scale)

alien_invasion/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().__init__() # python3
        # super(Bullet, self).__init__() # python2
        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)