title: Draw a square in Python Turtle
body: <p>I am following a tutorial for Python learning and I can't get the screen to open to draw. I don't get an error, it just shows that the program finish running.
  Maybe I missed something, can someone point it out?</p>
  
  <pre><code> import turtle #acutally called turtle to draw a turtle beautiful also used 
  to draw other stuff
  
   # to draw a square or eventually a turtle you need to do this things below
    # to draw a square you want to : move forward,turn right,move forward,turn 
   right,move forward turn right
  def draw_square(): #draw square for turtles
      window = turtle.Screen() #this is the background where the turtle will 
    move
  window.bgcolor("red") # the color of the screen
  brad = turtle.Turtle() #this is how to start drawing like time.sleep you use turtle.Turtle
  brad.forward(100)#move turtle forward takes in a number which is the distance to move forward
  brad.forward(90)# moves right 
  brad.forward(100)
  brad.forward(90)
  brad.forward(100)
  brad.forward(90)
  brad.forward(100)
  brad.forward(90)
  window.exitonclick() #click the screen to close it
  draw_square()
  </code></pre>