如何解决我不断收到的这个关键错误？

Question

import math
import random
import pygame
import tkinter as tk
from tkinter import messagebox

class cube(object):
    rows = 20
    w = 500
    def __init__(self,start,dirnx=1,dirny=0,color=(255,0,0)):
        self.pos = start
        self.dirnx = 1
        self.dirny = 0
        self.color = color

    def move(self, dirnx, dirny):
        self.dirnx = dirnx
        self.dirny = dirny
        self.pos = (self.pos[0] + self.dirnx, self.pos[1] + self.dirny)
    def draw(self, surface):
        dis = self.w // self.rows
        i = self.pos[0]
        j = self.pos[1]

        pygame.draw.rect(surface, self.color, (i*dis+1, j*dis+1, dis-2, dis-2))
        if eyes: 
            centre = dis//2
            radius = 3
            circleMiddle = (i*dis+centre-radius,j*dis+8)
            circleMiddle2 = (i*dis + dis -radius*2, j*dis+8)
            pygame.draw.circle(surface, (0,0,0), circleMiddle, radius)
            pygame.draw.circle(surface, (0,0,0), circleMiddle2, radius)

class snake(object):
    body = []
    turns = {}
    def __init__(self, color, pos):
        self.color = color
        self.head = cube(pos)
        self.body.append(self.head)
        self.dirnx = 0
        self.dirny = 1

    def move(self):
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()

            keys = pygame.key.get_pressed()

            for key in keys:
                if keys[pygame.K_LEFT]:
                    self.dirnx = -1
                    self.dirny = 0
                    self.turns[self.head.pos[:]] = [self.dirnx, self.dirny]

                elif keys[pygame.K_RIGHT]:
                    self.dirnx = 1
                    self.dirny = 0
                    self.turns[self.head.pos[:]] = [self.dirnx, self.dirny]

                elif keys[pygame.K_UP]:
                    self.dirnx = 0
                    self.dirny = -1
                    self.turns[self.head.pos[:]] = [self.dirnx, self.dirny]

                elif keys[pygame.K_DOWN]:
                    self.dirnx = 0
                    self.dirny = 1
                    self.turns[self.head.pos[:]] = [self.dirnx, self.dirny]

        for i, c in enumerate(self.body):
            p = c.pos[:]
            if p in self.turns:
                turn = self.turns[p]
                c.move(turn[0], turn[1])
            if i == len(self.body)-1:
                print(p, '-', self.turns)
                self.turns.pop(p)
            else:
                if c.dirnx == -1 and c.pos[0] <= 0: c.pos = (c.rows-1, c.pos[1])
                elif c.dirnx == 1 and c.pos[0] >= c.rows-1: c.pos = (0,c.pos[1])
                elif c.dirny == 1 and c.pos[1] >= c.rows-1: c.pos = (c.pos[0], 0)
                elif c.dirny == -1 and c.pos[1] <= 0: c.pos = (c.pos[0], c.rows-1)
                else: c.move(c.dirnx, c.dirny)

    def reset(self, pos):
        self.head = cube(pos)
        self.body = []
        self.body.append(self.head)
        self.turns = {}
        self.dirnx = 0
        self.dirny = 1

    def addCube(self):
        tail = self.body[-1]
        dx, dy = tail.dirnx, tail.dirny

        if dx == 1 and dy == 0:
            self.body.append(cube((tail.pos[0]-1, tail.pos[1])))
        elif dx == 1 and dy == 0:
            self.body.append(cube((tail.pos[0]+1, tail.pos[1])))
        elif dx == -1 and dy == 0:
            self.body.append(cube((tail.pos[0], tail.pos[1]-1)))
        elif dx == 0 and dy == -1:
            self.body.append(cube((tail.pos[0], tail.pos[1]+1)))

        self.body[-1].dirnx = dx
        self.body[-1].dirny = dy

    def draw(self, surface):
        for i, c in enumerate(self.body):
            if i == 0:
                c.draw(surface, True)
            else:
                c.draw(surface)

def drawGrid(w, rows,surface):
    sizeBtwn = w // rows

    x = 0
    y = 0 
    for l in range(rows):
        x = x + sizeBtwn
        y = y + sizeBtwn

        pygame.draw.line(surface, (255,255,255), (x,0), (x,w))
        pygame.draw.line(surface, (255,255,255), (0,y), (w,y))

def redrawWindow(surface):
    global rows, width, s, snack
    surface.fill((0,0,0))
    s.draw(surface)
    snack.draw(surface)
    drawGrid(width, rows, surface)
    pygame.display.update()

def randomSnack(rows, item):

    positions = item.body

    while True:
        x = random.randrange(rows)
        y = random.randrange(rows)
        if len(list(filter(lambda z:z.pos == (x,y), positions))) > 0:
            continue
        else:
            break

    return (x,y)

def message_box(subject, content):
    root = tk.TK()
    root.attributes("-topmost", True)
    root.withdraw()
    messagebox.showinfo(subject, content)
    try:
        root.destroy()
    except:
        pass

def main():
    global width, rows, s, snack
    width = 500 
    rows = 20
    win = pygame.display.set_mode((width,width))
    s = snake((255,0,0), (10,10))
    snack = cube(randomSnack(rows, s), color=(0,255,0))
    flag = True

    clock = pygame.time.Clock()

    while flag:
        pygame.time.delay(50)
        clock.tick(10)
        s.move()
        if s.body[0].pos == snack.pos:
            s.addCube()
            snack = cube(randomSnack(rows, s), color=(0,255,0))
        for x in range(len(s.body)):
            if s.body[x].pos in list(map(lambda z:z.pos, s.body[x+1:])):
                print('Score: ', len(s.body))
                message_box('You Lost!', 'Play again...')
                s.reset((10,10))
                break

        redrawWindow(win)

    pass

main()

我不断收到此错误：

     (10,10) - {}
     Traceback (most recent call last):
        File "snake.py" line 191, in <module>
           main()
        File "snake.py", line 176, in main
           s.move()
        File "snake.py", line 79, in move
           self.turns.pop(p)
     KeyError: (10, 10)

我相信 (10, 10) 指的是 (x, y) 我正在学习一个教程（深入的描述将帮助我理解如何解决这个问题）我相信这可能是我的元组，但我不确定如何要解决这个问题。我遵循了 TechWithTim 在 Youtube 上的教程。这是一个蛇程序，但我不确定这个错误是如何或意味着什么。蛇应该转动并被放置在一个网格中，但即使是 pygame 也拒绝启动。它在测试时确实开始了，但是在我让蛇移动后，程序停止工作并给了我这个错误。

Answer 1

我假设错误是从这个代码段抛出的：

if i == len(self.body)-1:
    print(p, '-', self.turns)
    self.turns.pop(p)

根据打印输出，self.turns 字典是空的，因此没有任何内容可以从中弹出。你必须弄清楚为什么字典是空的，为什么它不应该是空的。

会不会是缩进不对？如果测试p in self.turns 为真，也许您只想从turns 中删除p？