I'm trying to make a square with python. Here's the code:
import turtle
def draw_square():
    window = turtle.Screen()
    window.bgcolor("red")
    brad = turtle.Turtle()
    brad.shape("turtle")
    brad.color("yellow")
    brad.speed(2)
    brad.forward(100)
    brad.right(90)
    brad.forward(100)
    brad.right(90)
    brad.forward(100)
    brad.right(90)
    brad.forward(100)
    brad.right(90)
    window.exitonclick()
draw_square()
But I get this error:
File "C:/Python27\turtle.py", line 4, in draw_square
  window = turtle.Screen()
AttributeError: 'module' object has no attribute 'Screen'
 
     
    