#!/usr/bin/env python3
""" turtle-example-suite:

 tdemo_yinyang.py

Another drawing suitable as a beginner's
programming example.

The small circles are drawn by the circle
command.

"""

from turtle import *

def yin(radius, color1, color2):
 width(3)
 color("black", color1)
 begin_fill()
 circle(radius/2., 180)
 circle(radius, 180)
 left(180)
 circle(-radius/2., 180)
 end_fill()
 left(90)
 up()
 forward(radius*0.35)
 right(90)
 down()
 color(color1, color2)
 begin_fill()
 circle(radius*0.15)
 end_fill()
 left(90)
 up()
 backward(radius*0.35)
 down()
 left(90)

def main():
 reset()
 yin(200, "black", "white")
 yin(200, "white", "black")
 ht()
 return "Done!"

if __name__ == '__main__':
 main()
 mainloop()