python-3.6.zip added from Github

README.cosmo contains the necessary links.

third_party/python/Lib/turtledemo/yinyang.py

@@ -0,0 +1,49 @@
+#!/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()