import turtle
t = turtle.Turtle()
t.speed(5) # 1:slowest, 3:slow, 5:normal, 10:fast, 0:fastest
t.width(5)
x=100
for r in range(4):
  for side in [1, 2, 3, 4]:
    t.fd(100)
    t.rt(90)
  t.penup()
  t.rt(45)
  t.fd(15)
  t.lt(45)
  t.pendown()