[morelisp]

The only one I had not heard of before is a relatively recent addition, __class_getitem__. To Python's credit, I immediately (and correctly) guessed what it did from the name. I have used over half of them - if you have even written anything that needs to show docstring/typing information or a plugin loader you already cover nearly of them. I've used __index__, __slots__, and __mro__ more times than I can remember. The ones I haven't used are mostly because they are Python 3.4+.

But, critically, you won't find anything other than __slots__ and __index__ (and maybe __subclasshook__ if the code you're working on was from someone who drank the ABC koolaid back in the day) in "normal code" - they're there for people who want to hook into language internals, the kind of thing you'd usually find #pragma'd in C++.

With C++, on the other hand, you run into this kind of complexity just trying to solve "ordinary" problems. And it bears repeating, the "safe subset" between projects is different. It's not the only language with this problem (Common Lisp suffers greatly from it), but it's the one that offers the least in return and breaks the hardest when you get it wrong.