It does seem strange to say "However, there are plenty of languages that don’t provide built in support for such a function, leaving you on your own." and then show examples in Python.

If you are using Excel, you might find my blog entry useful: http://kiyototamura.tumblr.com/post/91613880102/generating-a...

There's value in knowing how it's implemented.

Further, there is value in knowing what makes the incorrect ways incorrect. :)

Also, even in the article it noted to use a library if your language allows.