Space Invaders Week 1

import turtle


wn = turtle.Screen()
wn.bgcolor("black")
wn.title("Space Invaders")

#border
border_pen = turtle.Turtle()
border_pen.speed(0)
border_pen.color("white")
border_pen.penup()
border_pen.setposition(-300,-300)
border_pen.pendown()
border_pen(3)
border_pen
for side in range(4):
    border_pen.fd(600)
    border_pen.lt(90)
border_pen.hideturtle()


player = turtle.Turtle()
player.color("blue")
player.shape("triangle")
player.penup()
player.speed(0)
player.setposition(0, -250)
player.setheading(90)



delay = input("Press enter to finish.")