Python编程——从入门到实践外星人入侵项目

练习这个项目时，我用的编辑器是pycharm,然后安装第三方库pygame（功能很强大），这个项目代码还是比较多的，需要学习管理包含多个文件的项目，体会到函数以及变量命名方法还需要重构很多代码，以提高代码的效率，总之，对于刚入门来说，是一个用来练手的一个非常不错的项目。
安装pygame这里就不多说了，下面是我完成所有操作后的代码：
alien_invasion.py

import sys
import pygame
from pygame.sprite import Group
from setting 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pygame,设置和屏幕对象
    pygame.init()#初始化背景设置
    ai_settings= Settings() #创建Settings实例，并将其存储在变量ai_settings中
    screen = pygame.display.set_mode((ai_settings.screen_width, ai_settings.screen_height))#创建一个名为screen的显示窗口
    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)
    # 创建飞船,子弹编组和外星人编组
    ship = Ship(ai_settings, screen)
    bullets = Group()
    aliens = Group()
    # 创建一个外星人群
    gf.create_fleet(ai_settings, screen, ship, aliens)

    # 开始游戏主循环
    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, sb, screen, ship, aliens, bullets)
        gf.update_screen(ai_settings, screen, stats, sb, ship, aliens, bullets, play_button)


run_game()#初始化游戏，并开始主循环

setting.py

class Settings():
    """存储游戏中所有设置的类"""
    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)#设定创建的显示窗口的大小，以及颜色
        # 飞船的设置
        self.ship_limit = 3
        # 子弹设置
        self.bullet_width = 300
        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 = 1.1
        #外星人点数提高速度
        self.score_scale = 1.5
        self.initialize_dynamic_settings()

    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表示向右移，为-1表示向左移
        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)
        print(self.alien_points)

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("C:\python项目文件\飞机大战\images\ship.bmp")
        self.rect = self.image.get_rect()
        self.screen_rect = screen.get_rect()#把表示屏幕的矩形存储在其中

        # 将每艘飞船放在屏幕底部中央
        self.rect.centerx = self.screen_rect.centerx #self.rect.centerx飞船的中心坐标设置为表示屏幕的中心坐标，即飞船在屏幕中心
        self.rect.bottom = self.screen_rect.bottom#飞船下边缘y坐标设置为表示屏幕的矩形的属性bottom
        # 在飞船属性centerx中存储小数值
        self.center = float(self.rect.centerx)#使用函数float()将self.rect.centerx的值转换为小数
        self.bottom = float(self.rect.bottom)

        # 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
        #在pygame中，原点位于屏幕左上角
        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.bottom -= self.ai_settings.ship_speed_factor
        if self.moving_down and self.rect.bottom < self.screen_rect.bottom:
            self.bottom += self.ai_settings.ship_speed_factor


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

game_functions.py

import sys
from time import sleep
import pygame
from bullet import Bullet
from alien import Alien
from random import randint

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 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:#玩家单击游戏窗口的关闭按钮时，将检测到pygame.QUTT事件，调用sys.exit()退出事件
            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 update_bullets(ai_settings, screen, stats, sb, ship, aliens, bullets):
    """更新子弹位置，并删除消失的子弹"""
    #更新子弹位置
    bullets.update()
    # 删除以消失子弹
    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"""
    # 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 * len(aliens)
            sb.prep_score()
        check_high_score(stats, sb)
    if len(aliens) == 0:
        # 删除现有子弹, 加快游戏节奏，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)

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，并加入到编组bullet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"""
    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):
            #创建一个外星人并加入当前行
            create_alien(ai_settings, screen, aliens, alien_number, row_number)

def get_number_aliens_x(ai_settings, alien_width):
    """计算每行可容纳多少外星人"""
    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 create_alien(ai_settings, screen, aliens, alien_number, row_number):
    """创建一个外星人并将它放在当前行"""
    alien = Alien(ai_settings, screen)
    alien_width = alien.rect.width
    alien.x = alien_width + 2 * alien_width * alien_number
    #alien.x = randint(10,30) + 2 * alien_width * alien_number  随机生成位置
    alien.rect.x = alien.x
    alien.rect.y = alien.rect.height + 2 * alien.rect.height * row_number
    #alien.rect.y = randint(-30,0) + 2 * alien.rect.height * row_number 随机生成位置
    aliens.add(alien)
def get_number_rows(ai_settings, ship_height, alien_height):
    """计算屏幕可容纳多少外星人"""
    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 ship_hit(ai_settings, stats, sb, screen, ship, aliens, bullets):
    """响应被外星人撞到的飞船"""
    if stats.ships_left > 0:
        #将ship_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()
        #创建一群外星人，并将飞船放到屏幕底部中央
        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, stats, sb, screen, 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:
            #像飞船被撞到一样处理
            ship_hit(ai_settings, stats, sb, screen, ship, aliens, bullets)
            break
def update_aliens(ai_settings, stats, sb, screen, 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()
    #检测外星人和飞船之间的碰撞
    if pygame.sprite.spritecollideany(ship, aliens):
        ship_hit(ai_settings, stats, sb, screen, ship, aliens, bullets)
        print('ship hit!!!')
    # 检查是否有外星人到达屏幕底端
    check_aliens_bottom(ai_settings, stats, sb, screen, 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):
    """将整群外星人下移并改变方向"""
    for alien in aliens.sprites():
        alien.rect.y += ai_settings.fleet_drop_speed
    ai_settings.fleet_direction *= -1


def check_high_score(stats, sb):
    """检查是否产生了最高分"""
    if stats.score > stats.high_score:
        stats.high_score = stats.score
        sb.prep_high_score()

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，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
        # 存储用小数表示子弹的位置
        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)

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("C:\python项目文件\飞机大战\images\lien.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

    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

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
        # 在任何时候都不应重置最高得分
        self.high_score = 1

    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

button.py

import pygame.font

class Button():
    def __init__(self, ai_setings, screen, msg):
        """初始化按钮的属性"""
        self.screen = screen
        self.screen_rect = screen.get_rect()

        #设置按钮属性和其他属性
        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)

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图像
        self.prep_score()
        self.prep_high_score()
        self.prep_level()
        self.prep_ships()

    def prep_score(self):
        """将得分渲染为一幅渲染的图像"""
        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 show_score(self):
        """在屏幕上显示当前得分和最高得分"""
        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):
        """将最高分转化为渲染的图像"""
        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):
        """显示还剩余多少飞船"""
        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)

以上便是外星人这个项目的全部代码，在练习的时候我也是同样遇到过很多问题，后面会将这些问题补充上来，这里也比较多，我会将项目文件上传，大家可以下载看看效果。
这里是效果图：

我这里将子弹宽度是设置为300。
这里是代码文件以及图片下载链接：https://download.csdn.net/download/weixin_45054387/12333195