Snake game

import turtle
import time
import random

delay = 0.1


#setup the screen
wn = turtle.Screen()
wn.title('Snake')
wn.bgcolor('blue')
wn.setup(width=600, height=600)
wn.tracer(0)

#snake head
head = turtle.Turtle()
head.speed(0)
head.shape('square')
head.color('green')
head.penup()
head.goto(0,0)
head.direction = "stop"


#snake food
food = turtle.Turtle()
food.speed(0)
food.shape('circle')
food.color('red')
food.penup()
food.goto(0,100)

segments = []



#functions
def go_up():
    head.direction = "up"

def go_down():
    head.direction = "down"

def go_right():
    head.direction = "right"

def go_left():
    head.direction = "left"

def move():
    if head.direction == "up":
        y = head.ycor()
        head.sety(y + 20)

    if head.direction == "down":
        y = head.ycor()
        head.sety(y - 20)

    if head.direction == "left":
        x = head.xcor()
        head.setx(x - 20)

    if head.direction == "right":
        x = head.xcor()
        head.setx(x + 20)

#Keyboard bindings
wn.listen()
wn.onkeypress(go_up, "w")
wn.onkeypress(go_down, "s")
wn.onkeypress(go_left, "a")
wn.onkeypress(go_right, "d")

# main game loop
while True:
    wn.update()

#check for a collision with the food
    if head.distance(food) < 20:

        #move the food to a random spot
        x = random.randint(-290, 290)
        y = random.randint(-290, 290)
        food.goto(x,y)

        # add a segment
        new_segment = turtle.Turtle()
        new_segment.speed(0)
        new_segment.shape("square")
        new_segment.color("grey")
        new_segment.penup()
        segments.append(new_segment)

        # move the end segments first in reverse order
        for index in range(len(segments)-1, 0, -1):
            x = segments[index-1].xcor()
            y = segments[index-1].ycor()
            segments[index].goto(x, y)

        # move segment 0 to where the head is
        if len(segments) > 0:
            x = head.xcor()
            y = head.ycor()
            segments[0].goto(x,y)


    move()

    time.sleep(delay)



wn.mainloop()