"""File:     draw_square.py
   Purpose:  Use the TurtleWorld module in Swampy to draw a square

   Run:      python draw_square.py

   Input:    None, except to terminate the program, click X to close
             the window
   Output:   A window with a square in it
   
   Note:     This is a solution to Exercise 4.3.1 in Python for 
             Software Design
"""

from TurtleWorld import *

def draw_sqr(t):      # Parameter is a turtle
   """Draw a square using the Turtle t
   """
   for i in range(4):
      fd(t, 100)
      lt(t)

world = TurtleWorld() # Create an instance of TurtleWorld -- i.e, a window
bob = Turtle()        # Create an instance of a Turtle
print bob

draw_sqr(bob)

wait_for_user()