Python 实现蛇游戏：蛇接触食物，食物保持在同一位置

import turtle
import time
import random

camara = turtle.Screen()
camara.title('bienvenido al juego de la serpiente.')
camara.setup(width=600, height=600)
camara.bgcolor("blue")
score = 0
total_score = 0
#texto
text = turtle.Turtle()

text.penup()
text.hideturtle()
text.color('red')
text.speed(0)
text.setpos(0, 250)
text.write(f'actual score {score} total score {total_score}', move=False, align='center', font=('candara', 24, 'bold'))

#cabeza

head = turtle.Turtle()

head.speed(1.4)

head.direction = 'stop'
head.shape('square')
head.shapesize(stretch_wid=1.1, stretch_len=1.1, outline=None)
head.color('red')
head.penup()
head.setpos(0, 0)

def arriba():
    while head.direction != 'down':
        head.direction = 'up'
        y = head.ycor()
        head.sety(y + 20)

def abajo():
    while head.direction != 'up':
        head.direction = 'down'
        y = head.ycor()
        head.sety(y - 20)

def izquierda():
    while head.direction != 'right':
        head.direction = 'left'
        x = head.xcor()
        head.setx(x - 20)

def derecha():
    while head.direction != 'left':
        head.direction = 'right'
        x = head.xcor()
        head.setx(x + 20)


camara.listen()
camara.onkeypress(arriba, 'w')
camara.onkeypress(izquierda, 'a')
camara.onkeypress(abajo, 's')
camara.onkeypress(derecha, 'd')
#food

food = turtle.Turtle()
food.penup()
food.shape('square')
food.speed(0)
x1 = random.randint(-270, 270)
y1 = random.randint(-270, 270)
food.setpos(x1, y1)

if food.distance(head) < 20:
    food.penup()
    food.shape('square')
    food.speed(0)
    x1 = random.randint(-270, 270)
    y1 = random.randint(-270, 270)
    food.setpos(x1, y1)

camara.mainloop()

大家好，我正在试着做一个《蛇的游戏》，我做了一个算法，当蛇接触到食物时，食物消失，然后再次出现在 map 上的随机位置，但不知何故，它似乎不起作用，因为当蛇接触食物时，食物仍然保持在相同的位置，所以在那之后，我做了这个算法(添加一个While True):

food = turtle.Turtle()
while True:
    food.penup()
    food.shape('square')
    food.speed(0)
    x1 = random.randint(-270, 270)
    y1 = random.randint(-270, 270)
    food.setpos(x1, y1)

为了弄清楚食物是否随机地看起来足够好，确实是这样，但当我开始移动蛇头时，循环停止运行，(蛇继续移动)，食物保持不变.我是说... 当我执行这些代码行时:

def arriba():
    while head.direction != 'down':
        head.direction = 'up'
        y = head.ycor()
        head.sety(y + 20)

def abajo():
    while head.direction != 'up':
        head.direction = 'down'
        y = head.ycor()
        head.sety(y - 20)

def izquierda():
    while head.direction != 'right':
        head.direction = 'left'
        x = head.xcor()
        head.setx(x - 20)

def derecha():
    while head.direction != 'left':
        head.direction = 'right'
        x = head.xcor()
        head.setx(x + 20)


camara.listen()
camara.onkeypress(arriba, 'w')
camara.onkeypress(izquierda, 'a')
camara.onkeypress(abajo, 's')
camara.onkeypress(derecha, 'd')

可以这么说，代码的其余部分停止运行. 那么这里的问题是什么呢？我应该怎么做才能让食物在每次蛇接触食物时都随机出现？谢谢.