Weird though when the author mentions the desire to rewrite Python functions in C.

The whole section about references was very confused. Especially for someone who supposedly knows C.

I suspect the issue is precisely that he's coming from C. In C, pass by value vs pass by reference is extremely explicit. In python, it's "magical", because it depends entirely on the type of the variable that is passed in, which is itself hidden from view of the code due to the dynamically typed nature of the language.

This has been one of my own annoyances with Python as well.

It doesn't depend on the type at all. Objects are never copied when passed (or assigned to names). The only thing that might give you the opposite impression is that some objects are immutable, so you wouldn't be able to notice if a copy were made (without calling `id`).