turtle ??

[Ömer sarı]

hi ,

l would like to ask a question as l m a little bit confused .l do practice in "how to think like a computer scientist:learning with python3.l installed python 2.7.10 and upper version 3.5 python.when l run  example code in the book , it gave me error.you can find the code , below.
""
import turtle             # Allows us to use turtles
 wn = turtle.Screen()      # Creates a playground for turtles
 alex = turtle.Turtle()    # Create a turtle, assign to alex

 alex.forward(50)          # Tell alex to move forward by 50 units
 alex.left(90)             # Tell alex to turn by 90 degrees
 alex.forward(30)          # Complete the second side of a rectangle

 wn.mainloop()             # Wait for user to close window

"" example code taken from "how to think like a computer scientist:learning with python3" chapter3. so l wonder which version of python l need to use for that code make work??.another question , is there any module which is named as arcpy?

 best regards.