turtle_example.py

from ext_turtle import *
from time import sleep

def infinity():
  setheading(0) ; pendown() ; color("blue") ; pensize(3)
  pendown() ; left(90) ; circle(50, 180) ; home() ; right(90) ; circle(50, 180)

def rosace():
  setheading(0) ; pendown() ; pensize(1)
  colors = ['red', 'magenta', 'blue', 'cyan', 'green', 'white', 'yellow']
  for _ in range(6):
  	for col in colors:
  	  pencolor(col) ; circle(50) ; left(10)

def von_koch():
  def _von_koch(n,L):
    if n == 0 : forward(L)
    else : _von_koch(n-1,L/3) ; left(60) ; _von_koch(n-1,L/3) ; right(120) ; _von_koch(n-1,L/3) ; left(60) ; _von_koch(n-1,L/3)
  setheading(0) ; pendown() ; color("magenta") ; pensize(1)
  for i in range(6): clear() ; penup() ; goto(0, 111) ; pendown() ; _von_koch(i, 320) ; sleep(1)

von_koch()
#rosace()
#infinity()