I'm not fond of the example given in the post, but I've very happily used __init_subclass__ in a few places where I previously would have needed a decorator. Eg

I'm not fond of the example given in the post, but I've very happily used __init_subclass__ in a few places where I previously would have needed a decorator. Eg, for "plugin-like" things where I would have otherwise needed a decorator to keep track, or iterated over subclasses, now can just "register" subclasses without any extra work on the child classes. Things that I normally wouldn't expect to change the behavior of the subclass, but where having a no-effort hook at subclass creation time can be extremely useful.