Python实现贪吃蛇一

贪吃蛇是一款经典的小游戏，最近尝试用Python实现它。先做一个基础版本实现以下目标：

1、做一个按钮，控制游戏开始

2、按Q键退出游戏

3、右上角显示一个记分牌

4、随机生成一个食物，蛇吃到食物后长度加一，得10分

5、蛇碰到边缘，游戏结束

6、蛇碰到自己，游戏结束

主流程代码（gluttonous_snake.py）如下：

import sysimport pygame
import randomfrom settings import Settings
from snake import Snake
from game_stats import GameStats
from button import Button
from food import Food
from scoreboard import Scoreboardclass GluttonousSnake:""" 管理游戏资源和行为的类 """def __init__(self):""" 初始化游戏并创建游戏资源 """pygame.init()self.settings = Settings()self.screen = pygame.display.set_mode((self.settings.screen_width, self.settings.screen_height))pygame.display.set_caption("贪吃蛇")# 创建一个用于存储游戏统计信息的实例self.stats = GameStats(self)# 创建记分牌self.sb = Scoreboard(self)self.food = Food(self)self.snakes = []self._create_snakes()# 创建Play按钮self.play_button = Button(self, "Play")def _create_snakes(self):""" 初始化创建长度为3的蛇 """for snake_number in range(3):self._create_snake(snake_number)def _create_snake(self, snake_number):""" 创建一段蛇身 """snake = Snake(self)self.screen_rect = self.screen.get_rect()snake.x = self.settings.screen_width / 2snake.y = self.settings.screen_height / 2 + snake_number * self.settings.snake_heightsnake.rect.x = snake.xsnake.rect.y = snake.yself.snakes.append(snake)def _check_events(self):# 监视键盘和鼠标的事件for event in pygame.event.get():if event.type == pygame.QUIT:sys.exit()elif event.type == pygame.KEYDOWN:self._check_keydown_events(event)elif event.type == pygame.MOUSEBUTTONDOWN:mouse_pos = pygame.mouse.get_pos()self._check_play_button(mouse_pos)def _check_play_button(self, mouse_pos):""" 在玩家单击Play按钮时开始新游戏 """button_clicked = self.play_button.rect.collidepoint(mouse_pos)if button_clicked and not self.stats.game_active:# 重置游戏设置self.stats.game_active = True# 隐藏鼠标光标pygame.mouse.set_visible(False)self.stats.score = 0self.sb.prep_score()self.settings.snake_direction = 'up'# 清空余下的蛇身self.snakes.clear()# 重新创建蛇身self._create_snakes()def _check_keydown_events(self, event):# 响应按键if event.key == pygame.K_RIGHT:if self.settings.snake_direction == 'up' or self.settings.snake_direction == 'down':self.settings.snake_direction = 'right'elif event.key == pygame.K_LEFT:if self.settings.snake_direction == 'up' or self.settings.snake_direction == 'down':self.settings.snake_direction = 'left'elif event.key == pygame.K_UP:if self.settings.snake_direction == 'right' or self.settings.snake_direction == 'left':self.settings.snake_direction = 'up'elif event.key == pygame.K_DOWN:if self.settings.snake_direction == 'right' or self.settings.snake_direction == 'left':self.settings.snake_direction = 'down'elif event.key == pygame.K_q:sys.exit()def _update_snakes(self):""" 更新蛇 """snake_head = self.snakes[0]self._create_snake_head(snake_head.rect.x, snake_head.rect.y)""" 检查是否吃到食物 """eat_food = self._check_eat_food()if not eat_food:self.snakes.pop()def _check_edges(self):""" 蛇碰到边缘时采取相应的措施 """snake_head = self.snakes[0]if snake_head.check_edges():self.stats.game_active = False# 显示鼠标光标pygame.mouse.set_visible(True)def _check_eat_self(self, snake_head):""" 是否碰到自己 """for snake in self.snakes:if snake.rect.colliderect(snake_head.rect):self.stats.game_active = False# 显示鼠标光标pygame.mouse.set_visible(True)breakdef _check_eat_food(self):""" 检测蛇吃到食物 """snake_head = self.snakes[0]food = self.foodif snake_head.rect.colliderect(food.rect):food.rect.x = round(random.randrange(20, self.settings.screen_width - self.settings.snake_width * 2) / 20.0) * 20.0food.rect.y = round(random.randrange(20, self.settings.screen_height - self.settings.snake_height * 2) / 20.0) * 20.0self.stats.score += self.settings.food_scoreself.sb.prep_score()return Trueelse:return Falsedef _create_snake_head(self, x, y):""" 创建蛇头 """snake = Snake(self)if self.settings.snake_direction == 'up':snake.x = xsnake.y = y - self.settings.snake_heightelif self.settings.snake_direction == 'down':snake.x = xsnake.y = y + self.settings.snake_heightelif self.settings.snake_direction == 'right':snake.x = x + self.settings.snake_widthsnake.y = yelif self.settings.snake_direction == 'left':snake.x = x - self.settings.snake_widthsnake.y = ysnake.rect.x = snake.xsnake.rect.y = snake.yself._check_eat_self(snake)self.snakes.insert(0, snake)def run_game(self):""" 开始游戏的主循环 """while True:self._check_events()if self.stats.game_active:if self.settings.update_count % 500 == 0: #控制游戏速度self._update_snakes()self._check_edges()self.settings.update_count = 0self.settings.update_count += 1self._update_screen()def _update_screen(self):# 每次循环时都会重绘屏幕self.screen.fill(self.settings.bg_color)self.food.draw_food()for snake in self.snakes:snake.draw_snake()# 如果游戏处于非活动状态，就绘制Play按钮if not self.stats.game_active:self.play_button.draw_button()# 显示得分self.sb.show_score()# 让最近绘制的屏幕可见pygame.display.flip()if __name__ == '__main__':# 创建实例并运行游戏ai = GluttonousSnake()ai.run_game()

按钮类（button.py）：

import pygame.fontclass Button:def __init__(self, ai_game, msg):""" 初始化按钮的属性 """self.screen = ai_game.screenself.screen_rect = self.screen.get_rect()# 设置按钮的尺寸和其他属性self.width, self.height = 100, 50self.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.centerself.rect.y = 100# 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.centerdef 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)

食物类（food.py）：

import pygameclass Food:def __init__(self, ai_game):""" 创建一个蛇身对象 """super().__init__()self.screen = ai_game.screenself.screen_rect = ai_game.screen.get_rect()self.settings = ai_game.settingsself.color = self.settings.food_color# 在（0,0）处创建一个表示食物的矩形，再设置正确的位置self.rect = pygame.Rect(0, 0, self.settings.food_width,self.settings.food_height)# 对于每个食物，都将其放在屏幕底部的中央self.rect.x = self.settings.screen_width / 2self.rect.y = self.settings.screen_height - 100# 在食物的属性x中存储小数值self.x = float(self.rect.x)# 存储用小数点表示的食物位置self.y = float(self.rect.y)def draw_food(self):""" 在屏幕上绘制食物 """pygame.draw.rect(self.screen, self.color, self.rect)

游戏状态（game_stats.py）：

class GameStats:""" 跟踪游戏的统计信息 """def __init__(self, ai_game):""" 初始化统计信息 """self.settings = ai_game.settingsself.reset_stats()# 游戏刚启动时处于非活动状态self.game_active = Falsedef reset_stats(self):""" 初始化在游戏运行期间可能变化的统计信息 """self.score = 0

游戏设置（settings.py）：

class Settings:def __init__(self):""" 初始化游戏的静态设置 """# 屏幕设置self.screen_width = 800self.screen_height = 600self.bg_color = (230, 230, 230)# 游戏设置self.update_count = 1# 蛇身设置self.snake_width = 20self.snake_height = 20self.snake_color = (0, 230, 0)self.snake_direction = 'up'# 食物设置self.food_width = 20self.food_height = 20self.food_color = (230, 0, 0)self.food_score = 10

记分牌（scoreboard.py）：

import pygame.font
from pygame.sprite import Groupclass Scoreboard:""" 显示得分信息的类 """def __init__(self, ai_game):""" 初始化显示得分涉及的属性 """self.ai_game = ai_gameself.screen = ai_game.screenself.screen_rect = self.screen.get_rect()self.settings = ai_game.settingsself.stats = ai_game.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)# 准备初始得分的图像self.prep_score()def prep_score(self):""" 将得分转换为一副渲染的图像 """round_score = round(self.stats.score, -1)score_str = "{:,}".format(round_score)self.score_image = self.font.render(score_str, True,self.text_color, self.settings.bg_color)# 在屏幕右上角显示得分self.score_rect = self.score_image.get_rect()self.score_rect.right = self.screen_rect.right - 20self.score_rect.top = 20def show_score(self):""" 在屏幕上显示得分 """self.screen.blit(self.score_image, self.score_rect)

蛇对象（snake.py）：

import pygame
from pygame.sprite import Spriteclass Snake(Sprite):def __init__(self, ai_game):""" 创建一个蛇身对象 """super().__init__()self.screen = ai_game.screenself.screen_rect = ai_game.screen.get_rect()self.settings = ai_game.settingsself.color = self.settings.snake_color# 在（0,0）处创建一个表示一段蛇身的矩形，再设置正确的位置self.rect = pygame.Rect(0, 0, self.settings.snake_width,self.settings.snake_height)# 对于每段蛇身，都将其放在屏幕底部的中央self.rect.x = self.screen_rect.width + (self.settings.screen_width / 2)self.rect.y = self.screen_rect.height + (self.settings.screen_height / 2)# 在蛇身的属性x中存储小数值self.x = float(self.rect.x)# 存储用小数点表示的子弹位置self.y = float(self.rect.y)def draw_snake(self):""" 在屏幕上绘制蛇身 """pygame.draw.rect(self.screen, self.color, self.rect)def check_edges(self):""" 如果蛇位于屏幕边缘，就返回True """screen_rect = self.screen.get_rect()if self.rect.right >= screen_rect.right or self.rect.left <= 0 or self.rect.top <= 0 or self.rect.bottom >= screen_rect.bottom:return True

运行游戏，下面是初始界面：