title: Arrow Commands in Python Turtle
body: <p>I have been trying to put turtle in tkinter using the canvas feature. I want to be able to make a turtle etcher sketcher thing so that I can control the turtle with arrow keys. I cannot seem to get it to work and don't understand the error it spits out:</p>
  
  <p><code>NameError: name 'Screen' is not defined</code></p>
  
  <p>Here is my code:</p>
  
  <pre><code>import tkinter as tk
  import turtle
  
  window = tk.Tk()
  window.geometry("750x500")
  window.resizable(0,0)
  
  app = tk.Canvas(master = window,
                  width = 500,
                  height = 500,
                  bg = "white")
  app.pack()
  Screen()
  turtle = turtle.RawTurtle(app)
  turtle = turtle.Screen()
  
  def k1():
      move.forward(1)
  
  def k2():
      move.left(1)
  
  def k3():
      move.right(1)
  
  def k4():
      move.back(1)
  
  turtle.onkey(k1, "Up")
  turtle.onkey(k2, "Left")
  turtle.onkey(k3, "Right")
  turtle.onkey(k4, "Down")
  
  turtle.listen()
  window.mainloop()
  </code></pre>