CSC1002_2

from turtle import Turtle, Screen, mainloop
snake=Turtle()
screen=Screen()
KEY_UP,KEY_DOWN,KEY_LEFT,KEY_RIGHT="Up","Down","Left","Right"
g_direction="0"

def setSnake():
    snake.up()
    snake.setpos(0,0)
    snake.shape("square")
    snake.fillcolor("red")

def moveUp():
    global g_direction
    if g_direction!="Down":
        g_direction="Up"

def move():
    global g_direction
    x,y=snake.pos()
    if g_direction!="0":
        if g_direction=="Up":
            snake.setheading(90)
            if y<230:
                snake.forward(10)
            else:
                snake.forward(0)
            screen.update()
        screen.ontimer(move,200)


screen.onkey(moveUp,KEY_UP)
screen.listen()
#main
screen.setup(width=500, height=500, startx=None, starty=None)
setSnake()
move()
screen.mainloop()