import turtle
import time
b=turtle.Screen()
b.title("my window")
b.bgcolor("black")

t = turtle.Turtle()
t.color("white")
t.shape("turtle")
t.forward(100)
t.left(90)
t.forward(100)
t.left(90)
t.forward(100)
t.left(90)
t.forward(100)
t.left(90)
