pyppin is a library of "basic components" that can be used in a wide range of contexts -- things that could hypothetically live in a standard library, only there's no particular reason to put them in there. It is essentially a box of tools that are slightly less common than the basics, but are nonetheless damned useful in practice. If the main argument against adding something to the standard library is "why does it need to be in there, as opposed to elsewhere?" and it's not big enough to merit its own standalone package, this is a perfectly reasonable place to put it.

You can find the current catalogue of tools in the documentation. You can also directly browse the source code and the unittests, which are deliberately heavily commented and meant to be readable!