*This is a companion to the Julia companion for: "Vectors, Matrices, and Least Squares" by Boyd and Vandenberghe. Which you can find here: http://vmls-book.stanford.edu/.
You can find notebooks with implementations in both Python and Julia that are direct references to the companion.
This is best perused in conjunction to the first degree companion: http://vmls-book.stanford.edu/vmls-julia-companion.pdf.
You can also find a Python companion put together by Leung and Matyspura here: https://ses.library.usyd.edu.au/handle/2123/21370