1#!/usr/bin/env python
2"""       turtle-example-suite:
3
4            tdemo_yinyang.py
5
6Another drawing suitable as a beginner's
7programming example.
8
9The small circles are drawn by the circle
10command.
11
12"""
13
14from turtle import *
15
16def yin(radius, color1, color2):
17    width(3)
18    color("black")
19    fill(True)
20    circle(radius/2., 180)
21    circle(radius, 180)
22    left(180)
23    circle(-radius/2., 180)
24    color(color1)
25    fill(True)
26    color(color2)
27    left(90)
28    up()
29    forward(radius*0.375)
30    right(90)
31    down()
32    circle(radius*0.125)
33    left(90)
34    fill(False)
35    up()
36    backward(radius*0.375)
37    down()
38    left(90)
39
40def main():
41    reset()
42    yin(200, "white", "black")
43    yin(200, "black", "white")
44    ht()
45    return "Done!"
46
47if __name__ == '__main__':
48    main()
49    mainloop()
50