snake_game.py

#snake game
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):
    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 in 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,'green')

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

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()