如何在贪吃蛇游戏中添加再次玩功能

Question

此代码的大部分来自 Bro Code 的 Python 教程，介绍如何用 Python 制作贪吃蛇游戏。我决定添加一个“再玩一次？”游戏结束屏幕上的按钮，按下后将重置游戏并允许用户再次玩。 “new_game”函数是我添加的。

from tkinter import *
import random

GAME_WIDTH = 600
GAME_HEIGHT = 600
SPEED = 75
SPACE_SIZE = 50
BODY_PARTS = 3
SNAKE_COLOR = "#0000FF"
FOOD_COLOR = "#FFFF00"
BACKGROUND_COLOR = "#000000"

class Snake:

    def __init__(self):
        self.body_size = BODY_PARTS
        self.coordinates = []
        self.squares = []

        for  i in range(0, BODY_PARTS):
            self.coordinates.append([0,0])

        for x, y in self.coordinates:
            square = canvas.create_rectangle(x, y, x + SPACE_SIZE, y + SPACE_SIZE, fill=SNAKE_COLOR, tag = "snake")
            self.squares.append(square)

class Food:

    def __init__(self):

        x = random.randint(0, int(GAME_WIDTH/SPACE_SIZE)-1) * SPACE_SIZE
        y = random.randint(0, int(GAME_HEIGHT/SPACE_SIZE)-1) * SPACE_SIZE

        self.coordinates = [x, y]

        canvas.create_oval(x, y, x + SPACE_SIZE, y + SPACE_SIZE, fill=FOOD_COLOR, tag="food")

def next_turn(snake, food):

    x, y = snake.coordinates[0]

    if direction == "up":
        y -= SPACE_SIZE

    elif direction == "down":
        y += SPACE_SIZE

    elif direction == "left":
        x -= SPACE_SIZE

    elif direction == "right":
        x += SPACE_SIZE

    snake.coordinates.insert(0, (x, y))

    square = canvas.create_rectangle(x, y, x + SPACE_SIZE, y + SPACE_SIZE, fill=SNAKE_COLOR,)

    snake.squares.insert(0, square)

    if x == food.coordinates[0] and y == food.coordinates[1]:

        global score

        score += 1

        label.config(text="Score: {}".format(score))

        canvas.delete("food")

        food = Food()

    else:
        del snake.coordinates[-1]

        canvas.delete(snake.squares[-1])

        del snake.squares[-1]

    if check_collisions(snake):
        game_over()

    else:
        window.after(SPEED, next_turn, snake, food)

def change_direction(new_direction):

    global direction

    if new_direction == 'left':
        if direction != 'right':
            direction = new_direction

    elif new_direction == 'right':
        if direction != 'left':
            direction = new_direction

    elif new_direction == 'up':
        if direction != 'down':
            direction = new_direction

    elif new_direction == 'down':
        if direction != 'up':
            direction = new_direction

def check_collisions(snake):

    x, y, = snake.coordinates[0]

    if x < 0  or x>= GAME_WIDTH:
        return True
    elif y < 0  or y >= GAME_HEIGHT:
        return True

    for body_part in snake.coordinates[1:]:
        if x == body_part[0] and y == body_part[1]:
            return True

    return False

def game_over():

    global canvas

    canvas.delete(ALL)
    canvas.create_text(canvas.winfo_width() / 2,
                       canvas.winfo_height() / 2,
                       font=('consolas', 70),
                       text="GAME OVER",
                       fill="red",
                       tag="gameover")

#**BUTTON I ADDED**

    again = Button(canvas,
                   width=12,
                   height=2,
                   text="Play again?",
                   font=('consolas', 15),
                   bg="black",
                   fg="red",
                   activebackground="black",
                   activeforeground="red",
                   command=new_game)
    again.place(relx=0.5, rely=0.65, anchor=CENTER)

# **FUCNTION SUPPOSED TO RESET GAME**

def new_game():

    global canvas

    score = 0

    canvas.destroy()
    label.config(text="Score:{}".format(score))

    canvas = Canvas(window,
                    bg=BACKGROUND_COLOR,
                    height=GAME_HEIGHT,
                    width=GAME_WIDTH)
    canvas.pack()


window = Tk()
window.title("Snake game")
window.resizable(False, False)

score = 0
direction = 'down'

label = Label(window,
              text="Score:{}".format(score),
              font=('consolas', 40))
label.pack()

canvas = Canvas(window,
                bg=BACKGROUND_COLOR,
                height=GAME_HEIGHT,
                width=GAME_WIDTH)
canvas.pack()

window.update()
window_width = window.winfo_width()
window_height = window.winfo_height()
screen_width = window.winfo_screenwidth()
screen_height = window.winfo_screenheight()

x = int((screen_width / 2) - (window_width / 2))
y = int((screen_height / 2) - (window_height / 2))

window.geometry(f"{window_width}x{window_height}+{x}+{y}")

window.bind('<Left>', lambda event: change_direction('left'))
window.bind('<Right>', lambda event: change_direction('right'))
window.bind('<Up>', lambda event: change_direction('up'))
window.bind('<Down>', lambda event: change_direction('down'))
window.bind('<a>', lambda event: change_direction('left'))
window.bind('<d>', lambda event: change_direction('right'))
window.bind('<w>', lambda event: change_direction('up'))
window.bind('<s>', lambda event: change_direction('down'))

snake = Snake()
food = Food()

next_turn(snake, food)

window.mainloop()

我成功摧毁了“游戏结束”屏幕，将原来的画布添加回窗口，并重置分数，但我仍然不知道如何让蛇再次出现并重新开始游戏。

我尝试了一个 while 循环，它从一开始就是 True，当按下“再次播放”时将返回 False，而 while 循环将被破坏。但这并没有改变原始窗口中的任何内容，只是在原始窗口关闭时添加了一个相同的窗口。

Answer 1

可能是这样的

def new_game():
    global score
    global direction
    global snake
    global food
    
    again.destroy()
        
    score = 0           # reset score
    direction = 'down'  # reset direction

    canvas.delete('all')                 # reset canvas
    label.config(text=f"Score:{score}")  # reset label

    snake = Snake() # reset snake
    food = Food()   # reset food

    #snake.reset() # reset snake
    #food.reset()  # reset food

    next_turn(snake, food)  # run again loop