text: """This module contains a code example related to
  
  Think Python, 2nd Edition
  by Allen Downey
  http://thinkpython2.com
  
  Copyright 2015 Allen Downey
  
  License: http://creativecommons.org/licenses/by/4.0/
  """
  
  from __future__ import print_function, division
  
  import turtle
  
  
  def koch(t, n):
      """Draws a koch curve with length n."""
      if n < 10:
          t.fd(n)
          return
      m = n/3
      koch(t, m)
      t.lt(60)
      koch(t, m)
      t.rt(120)
      koch(t, m)
      t.lt(60)
      koch(t, m)
  
  
  def snowflake(t, n):
      """Draws a snowflake (a triangle with a Koch curve for each side)."""
      for i in range(3):
          koch(t, n)
          t.rt(120)
  
  
  bob = turtle.Turtle()
  
  bob.pu()
  bob.goto(-150, 90)
  bob.pd()
  snowflake(bob, 300)
  
  turtle.mainloop()