Arthur said:

...

Your opinion?

Very cool! Especially for someone like myself who would like to be getting a handle on generators.

Not just the how, but the why and when.

The only amendment I would like to see is tutorial type annotations. Recursive generators is a bit more than I seem to be able to fully follow without some help.

Is this a good candidate for Useless Python?

Art

I found it helpful to turn on the debugger before running this ("step" through items that are not turtle instructions, and "over" turtle instructions, just as one tends to step over everything that is not "print x"), and also to read and try http://www-106.ibm.com/developerworks/library/l-pycon.html?n-l-9271