Snake game.py

from random import randrange
from turtle import *

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 -200 < head.x < 190 and -200 < head.y < 190


def move():
    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, 'blue')
    update()
    ontimer(move, 250)


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()