Whenever I try to run my script it stops working

Question

I am currently making a py game and python stops working every time, but I'm not sure why.

from turtle import Turtle, Screen

screen = Screen()
screen.setup(600, 600)
screen.bgcolor('black')

screen.title('Snake Game')
turtles = []
y = 0
x = 0
for _ in range(3):
    turtle = Turtle('square')
    turtle.color('white')
    turtle.penup()
    turtle.goto(x, y)
    x -= 20


game_is_on = True
while game_is_on:
    for seg in turtles:
        seg.forward(20)

Answer 1

You have forgotten to add each turtle to the turtles list. All you need to do is append the turtle in the for loop.

Here is the code:

from turtle import Turtle, Screen

screen = Screen()
screen.setup(600, 600)
screen.bgcolor('black')

screen.title('Snake Game')
turtles = []
y = 0
x = 0
for _ in range(3):
    turtle = Turtle('square')
    turtle.color('white')
    turtle.penup()
    turtle.goto(x, y)
    turtles.append(turtle)
    x -= 20

game_is_on = True
while game_is_on:
    for seg in turtles:
        seg.forward(20)