Small and Large Stones of Programming

Every time I write a program in C, I am quire tired. I thought it was easier to write one by Python. So I wrote a demo program of raw socket communication. It was not so easy as I expected, but the following program sends (and receives) an Ethernet packet almost every second. (Whole this article is licensed by Creative Commons, but the program is in public domain; that is, it can be copied without any restriction.)

This is the first 3D-printing related program for this site because most of my 3D-printing programs are spagetti like. I believe this 3D turtle graphics library in Python can be used by other people, I first publish this.