Python實現貪吃蛇大作戰

貪吃蛇

初始版本

初始版本，只存在基本資料結構——雙向佇列。

遊戲思路

貪吃蛇透過不斷得吃食物來增長自身，如果貪吃蛇碰到邊界或者自身則遊戲失敗。

食物是綠色矩形來模擬，座標為隨機數生成，定義一個蛇長變數，判斷蛇頭座標和食物座標是否接近，如果蛇頭接近食物，蛇長增加一個單位。

蛇結構體透過雙向佇列實現蛇的移動和增長。用pygame相應庫函式讀取鍵盤事件，每次事件發生都對應蛇頭的相應方向，例如按鍵盤下鍵貪吃蛇向下走。蛇的移動是透過在隊頭新增一個新的座標，然後刪掉隊尾元素實現的。佇列的長度始終為蛇長變數的值。

得分變數為蛇長變數減去一個單位，初始化的時候蛇長就為1個單位長度，故而需要減1。

完整程式碼

import pygame
import random

pygame.init()

# 以RGB的形式定義顏色
white = (255, 255, 255)
yellow = (255, 255, 102)
black = (0, 0, 0)
red = (213, 50, 80)
green = (0, 255, 0)
blue = (50, 153, 213)

# 設定窗體大小
dis_width = 800
dis_height = 600
dis = pygame.display.set_mode((dis_width, dis_height))
pygame.display.set_caption('貪吃蛇 KevenDuan1.0')

# 建立clock物件
clock = pygame.time.Clock()

# 蛇的寬度
snake_block = 15
# 蛇的速度
snake_speed = 15

# 從系統庫裡獲取字型
font_style = pygame.font.SysFont("bahnschrift", 25)
score_font = pygame.font.SysFont("comicsansms", 35)

def Your_score(score):
    value = score_font.render("Score: " + str(score), True, yellow)
    # 在主surface裡新增字型surface
    dis.blit(value, [0, 0])

def our_snake(snake_block, snake_list):
    for x in snake_list:
        pygame.draw.rect(dis, black, [x[0], x[1], snake_block, snake_block])

def message(msg, color):
    mesg = font_style.render(msg, True, color)
    dis.blit(mesg, [dis_width // 2 - 180, dis_height // 2])

def gameLoop():
    game_over = False
    game_close = False

    x1 = dis_width / 2
    y1 = dis_height / 2

    x1_change = 0
    y1_change = 0

    # 存放蛇的身體
    snake_List = []
    # 蛇的長度
    Length_of_snake = 1

    # 食物座標隨機生成
    foodx = round(random.randrange(snake_block, dis_width - snake_block, snake_block))
    foody = round(random.randrange(snake_block, dis_height - snake_block, snake_block))
    print(foodx, foody)

    while not game_over:
        while game_close == True:
            dis.fill(blue)
            message("Game over, press p again or q quit!", red)
            Your_score(Length_of_snake - 1)
            # 修改得分
            pygame.display.update()

            for event in pygame.event.get():
                if event.type == pygame.KEYDOWN:
                    if event.key == pygame.K_q:
                        game_over = True
                        game_close = False
                    if event.key == pygame.K_p:
                        gameLoop()

        # 獲取事件
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                game_over = True
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_LEFT or event.key == pygame.K_a:
                    x1_change = -snake_block
                    y1_change = 0
                elif event.key == pygame.K_RIGHT or event.key == pygame.K_d:
                    x1_change = snake_block
                    y1_change = 0
                elif event.key == pygame.K_UP or event.key == pygame.K_w:
                    y1_change = -snake_block
                    x1_change = 0
                elif event.key == pygame.K_DOWN or event.key == pygame.K_s:
                    y1_change = snake_block
                    x1_change = 0

        if x1 >= dis_width or x1 < 0 or y1 >= dis_height or y1 < 0:
            # 判斷為遊戲失敗
            game_close = True

        x1 += x1_change
        y1 += y1_change

        dis.fill(blue)
        pygame.draw.rect(dis, green, [foodx, foody, snake_block, snake_block])
        snake_Head = []
        snake_Head.append(x1)
        snake_Head.append(y1)
        snake_List.append(snake_Head)
        # 貪吃蛇的移動
        if len(snake_List) > Length_of_snake:
            del snake_List[0]

        # 判斷是否咬到自身
        for x in snake_List[:-1]:
            if x == snake_Head:
                game_close = True

        # 畫蛇出來
        our_snake(snake_block, snake_List)
        Your_score(Length_of_snake - 1)

        # 更新畫面
        pygame.display.update()

        # 判斷蛇是否遲到食物
        if foodx - 10 <= x1 <= foodx + 10 and foody - 10 <= y1 <= foody + 10:
            foodx = round(random.randrange(snake_block, dis_width - snake_block, snake_block))
            foody = round(random.randrange(snake_block, dis_height - snake_block, snake_block))
            # print(foodx, foody)
            Length_of_snake += 1

        # 調節幀率來控制蛇的速度
        clock.tick(snake_speed)

    pygame.quit()
    quit()

gameLoop()

程式碼講解

使用的pygame和random兩個庫。Pygame是一種流行的Python遊戲開發庫，它提供了許多功能，使開發人員可以輕鬆建立2D遊戲。它具有良好的跨平臺支援，可以在多個作業系統上執行。random庫是用來獲取隨機數的，後面使用其獲取食物的隨機座標。

import pygame
import random

初始化一些後期用到的引數，以及初始化pygame，建立clock時鐘物件。

# 初始化pygame
pygame.init()
# 以RGB的形式定義顏色
white = (255, 255, 255)
yellow = (255, 255, 102)
black = (0, 0, 0)
red = (213, 50, 80)
green = (0, 255, 0)
blue = (50, 153, 213)

# 設定窗體大小
dis_width = 800
dis_height = 600
dis = pygame.display.set_mode((dis_width, dis_height))
# 設定窗體的名稱
pygame.display.set_caption('貪吃蛇 KevenDuan1.0')

# 建立clock物件
clock = pygame.time.Clock()

# 蛇的寬度
snake_block = 15
# 蛇的速度
snake_speed = 15

# 從系統庫裡獲取字型
font_style = pygame.font.SysFont("bahnschrift", 25)
score_font = pygame.font.SysFont("comicsansms", 35)

定義得分函式，實際上就是在畫面中新增字型。

def Your_score(score):
    value = score_font.render("Score: " + str(score), True, yellow)
    # 在主surface裡新增字型surface
    dis.blit(value, [0, 0])

定義蛇體函式，實際上就是遍歷蛇身佇列，依次在畫面中畫出矩形。

def our_snake(snake_block, snake_list):
    for x in snake_list:
        pygame.draw.rect(dis, black, [x[0], x[1], snake_block, snake_block])

定義文字函式，實際上就是在畫面中顯示文字。

def message(msg, color):
    mesg = font_style.render(msg, True, color)
    dis.blit(mesg, [dis_width // 2 - 180, dis_height // 2])

兩個迴圈結構一個判斷遊戲是否結束一個判斷遊戲是否需要退出。

    while not game_over:
        while game_close == True:
            dis.fill(blue)
            message("Game over, press p again or q quit!", red)
            Your_score(Length_of_snake - 1)
            # 修改得分
            pygame.display.update()

            for event in pygame.event.get():
                if event.type == pygame.KEYDOWN:
                    if event.key == pygame.K_q:
                        game_over = True
                        game_close = False
                    if event.key == pygame.K_p:
                        gameLoop()

獲取鍵盤事件改變蛇頭方向

# 獲取事件
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                game_over = True
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_LEFT or event.key == pygame.K_a:
                    x1_change = -snake_block
                    y1_change = 0
                elif event.key == pygame.K_RIGHT or event.key == pygame.K_d:
                    x1_change = snake_block
                    y1_change = 0
                elif event.key == pygame.K_UP or event.key == pygame.K_w:
                    y1_change = -snake_block
                    x1_change = 0
                elif event.key == pygame.K_DOWN or event.key == pygame.K_s:
                    y1_change = snake_block
                    x1_change = 0

蛇的移動是透過在隊頭新增一個新的座標，然後刪掉隊尾元素實現的。佇列的長度始終為蛇長變數的值。

		x1 += x1_change
        y1 += y1_change

        dis.fill(blue)
        pygame.draw.rect(dis, green, [foodx, foody, snake_block, snake_block])
        snake_Head = []
        snake_Head.append(x1)
        snake_Head.append(y1)
        snake_List.append(snake_Head)
        # 貪吃蛇的移動
        if len(snake_List) > Length_of_snake:
            del snake_List[0]

        # 判斷是否咬到自身
        for x in snake_List[:-1]:
            if x == snake_Head:
                game_close = True

        # 畫蛇出來
        our_snake(snake_block, snake_List)
        Your_score(Length_of_snake - 1)

        # 更新畫面
        pygame.display.update()

判斷蛇頭是否吃到食物，設定一定的範圍，防止出現永遠吃不到的bug

# 判斷蛇是否吃到食物
        if foodx - 10 <= x1 <= foodx + 10 and foody - 10 <= y1 <= foody + 10:
            foodx = round(random.randrange(snake_block, dis_width - snake_block, snake_block))
            foody = round(random.randrange(snake_block, dis_height - snake_block, snake_block))
            # print(foodx, foody)
            Length_of_snake += 1

增加選單功能

透過查閱資料，發現pygame_menu提供了比較完善的遊戲選單功能。我透過pip下載後，查閱了官方樣例程式碼，這個選單確實是比較精美的，正是我所需要給遊戲新增的東西。

import pygame
import pygame_menu

pygame.init()

surface = pygame.display.set_mode((600, 400))

def set_difficulty(value, difficulty):
    # Do the job here !
    print(1)
    pass

def start_the_game():
    # Do the job here !
    pass

menu = pygame_menu.Menu('Welcome', 600, 400,
                       theme=pygame_menu.themes.THEME_BLUE)

menu.add.text_input('Name :', default='kevenduan')
menu.add.selector('Difficulty :', [('Hard', 1), ('Easy', 2)], onchange=set_difficulty)
menu.add.button('Play', start_the_game)
menu.add.button('Quit', pygame_menu.events.EXIT)
menu.mainloop(surface)

最終版本

新功能

最終版本新增了遊戲介面選單，有查詢得分記錄的功能，以及可以選擇兩個難度。

查詢分數透過列表記錄後，透過排序來顯示得分前5的分數。

難度的控制是由蛇的速度來控制，由於咬到自身就遊戲失敗有點坑，在這裡刪除了。

完整程式碼

import pygame
import random
import pygame_menu

score = [0, 0, 0, 0, 0]
pygame.init()
# 以RGB的形式定義顏色
white = (255, 255, 255)
yellow = (255, 255, 102)
black = (0, 0, 0)
red = (213, 50, 80)
green = (0, 255, 0)
blue = (50, 153, 213)

# 設定窗體大小
dis_width = 800
dis_height = 600
dis = pygame.display.set_mode((dis_width, dis_height))
pygame.display.set_caption('Snakes KevenDuan 1.0')

# 建立clock物件
clock = pygame.time.Clock()

# 蛇的寬度
snake_block = 15
# 蛇的速度
snake_speed = 15

# 從系統庫裡獲取字型
font_style = pygame.font.SysFont("bahnschrift", 25)
score_font = pygame.font.SysFont("comicsansms", 35)

def Your_score(score):
    value = score_font.render("Score: " + str(score), True, yellow)
    # 在主surface裡新增字型surface
    dis.blit(value, [0, 0])

def our_snake(snake_block, snake_list):
    for x in snake_list:
        pygame.draw.rect(dis, black, [x[0], x[1], snake_block, snake_block])

def message(msg, color):
    mesg = font_style.render(msg, True, color)
    dis.blit(mesg, [dis_width // 2 - 150, dis_height // 2])

def gameLoop():
    game_over = False
    game_close = False

    x1 = dis_width / 2
    y1 = dis_height / 2

    x1_change = 0
    y1_change = 0

    # 存放蛇的身體
    snake_List = []
    # 蛇的長度
    Length_of_snake = 1

    # 食物座標隨機生成
    foodx = round(random.randrange(snake_block, dis_width - snake_block, snake_block))
    foody = round(random.randrange(snake_block, dis_height - snake_block, snake_block))
    print(foodx, foody)

    while not game_over:
        while game_close == True:
            dis.fill(blue)
            score.append(Length_of_snake - 1)
            message(f"Game Over! your score is {Length_of_snake - 1}", red)
            Your_score(Length_of_snake - 1)
            # 修改得分
            pygame.display.update()
            pygame.time.wait(2000)
            # 顯示出選單
            menu.mainloop(dis)

        # 獲取事件
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                game_over = True
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_LEFT or event.key == pygame.K_a:
                    x1_change = -snake_block
                    y1_change = 0
                elif event.key == pygame.K_RIGHT or event.key == pygame.K_d:
                    x1_change = snake_block
                    y1_change = 0
                elif event.key == pygame.K_UP or event.key == pygame.K_w:
                    y1_change = -snake_block
                    x1_change = 0
                elif event.key == pygame.K_DOWN or event.key == pygame.K_s:
                    y1_change = snake_block
                    x1_change = 0

        if x1 >= dis_width or x1 < 0 or y1 >= dis_height or y1 < 0:
            # 判斷為遊戲失敗
            game_close = True

        x1 += x1_change
        y1 += y1_change

        dis.fill(blue)
        pygame.draw.rect(dis, green, [foodx, foody, snake_block, snake_block])
        snake_Head = []
        snake_Head.append(x1)
        snake_Head.append(y1)
        snake_List.append(snake_Head)
        # 貪吃蛇的移動
        if len(snake_List) > Length_of_snake:
            del snake_List[0]

        # 判斷是否咬到自身
        # for x in snake_List[:-1]:
        #     if x == snake_Head:
        #         game_close = True

        # 畫蛇出來
        our_snake(snake_block, snake_List)
        Your_score(Length_of_snake - 1)

        # 更新畫面
        pygame.display.update()

        # 判斷蛇是否吃到食物
        if foodx - 10 <= x1 <= foodx + 10 and foody - 10 <= y1 <= foody + 10:
            foodx = round(random.randrange(snake_block, dis_width - snake_block, snake_block))
            foody = round(random.randrange(snake_block, dis_height - snake_block, snake_block))
            # print(foodx, foody)
            Length_of_snake += 1

        # 調節幀率來控制蛇的速度
        clock.tick(snake_speed)

    pygame.quit()
    quit()



def set_difficulty(value, difficulty):
    # Do the job here !
    global snake_speed
    if snake_speed == 15: snake_speed = 30
    else: snake_speed = 15

def start_the_game():
    # Do the job here !
    gameLoop()

def rank():
    # flag = True
    while True:
        dis.fill(blue)
        score.sort()
        print(score)
        mesg1 = font_style.render(f"Your highest score is {score[-1]}", True, yellow)
        dis.blit(mesg1, [dis_width // 2 - 150, dis_height // 2 - 30])
        mesg2 = font_style.render(f"Ranking of scores:{score[-1:-6:-1]}", True, yellow)
        dis.blit(mesg2, [dis_width // 2 - 190, dis_height // 2 + 10])

        pygame.display.update()
        pygame.time.wait(3000)
        menu.mainloop(dis)
        # menu.add.button('Quit', pygame_menu.events.EXIT)
        # for event in pygame.event.get():
        #     if event.type == pygame.QUIT:
        #         flag = True

menu = pygame_menu.Menu('Welcome to my game', 800, 600,
                       theme=pygame_menu.themes.THEME_BLUE)

menu.add.text_input('Author :', default='KevenDuan')
menu.add.selector('Difficulty :', [('Easy', 1), ('Hard', 2)], onchange=set_difficulty)
menu.add.button('Yours socres', rank)
menu.add.button('Play', start_the_game)
menu.add.button('Quit', pygame_menu.events.EXIT)
menu.mainloop(dis)