游戏动图：

源码

from turtle import *
from random import randrange
from freegames import square, vector

food = vector(0, 0)
snake = [vector(10, 0)]
aim = vector(0, -10)

def change(x, y):
   "Change snake direction."
   aim.x = x
   aim.y = y

def inside(head):
   "Return True if head inside boundaries."
   return -200 < head.x < 190 and -200 < head.y < 190

def move():
   "Move snake forward one segment."
   head = snake[-1].copy()
   head.move(aim)

   if not inside(head) or head in snake:
       square(head.x, head.y, 9, 'red')
       update()
       return

   snake.append(head)

   if head == food:
       print('Snake:', len(snake))
       food.x = randrange(-15, 15) * 10
       food.y = randrange(-15, 15) * 10
   else:
       snake.pop(0)

   clear()

   for body in snake:
       square(body.x, body.y, 9, 'black')

   square(food.x, food.y, 9, 'green')
   update()
   ontimer(move, 100)

setup(420, 420, 370, 0)
hideturtle()
tracer(False)
listen()
onkey(lambda: change(10, 0), 'Right')
onkey(lambda: change(-10, 0), 'Left')
onkey(lambda: change(0, 10), 'Up')
onkey(lambda: change(0, -10), 'Down')
move()
done()     

运行

复制上述代码到一个 py 为后缀的文件，命名 snake.py.

在文件所在目录打开控制台：运行pip install freegames，然后运行python snake.py