Penrose Design Python programming Demo by G Krishna Chauhan

 Source Code

#!/usr/bin/env python3

"""       turtle-example-suite:

            tdemo_paint.py

A simple  event-driven paint program

- left mouse button moves turtle

- middle mouse button changes color

- right mouse button toggles between pen up

(no line drawn when the turtle moves) and

pen down (line is drawn). If pen up follows

at least two pen-down moves, the polygon that

includes the starting point is filled.

 -------------------------------------------

 Play around by clicking into the canvas

 using all three mouse buttons.

 -------------------------------------------

          To exit press STOP button

 -------------------------------------------

"""

from turtle import *

def switchupdown(x=0, y=0):

    if pen()["pendown"]:

        end_fill()

        up()

    else:

        down()

        begin_fill()

def changecolor(x=0, y=0):

    global colors

    colors = colors[1:]+colors[:1]

    color(colors[0])

def main():

    global colors

    shape("circle")

    resizemode("user")

    shapesize(.5)

    width(3)

    colors=["red", "green", "blue", "yellow"]

    color(colors[0])

    switchupdown()

    onscreenclick(goto,1)

    onscreenclick(changecolor,2)

    onscreenclick(switchupdown,3)

    return "EVENTLOOP"

if __name__ == "__main__":

    msg = main()

    print(msg)

    mainloop()