- format strings - mandatory keyword arguments - multi-dict splatting - nicer yield semantics for generators - Fixing system-specific encoding ambiguities

- format strings - mandatory keyword arguments - multi-dict splatting - nicer yield semantics for generators - Fixing system-specific encoding ambiguities - dataclasses - inline type annotations - better metaclass support - more introspection tooling - pathlib (for nicer path handling) - mocking pulled into the standard library in a cleaner way - stable ABIs for extensions - secrets handling - ellipsis instead of pass (yeah who cares but I care) - lots of standard lib API cleanup All of this is very helpful for making clean applications. But I would say it's _very_ helpful for making good libraries as well. This stuff is about having a strong language foundation to avoid plain weirdness like the click issue . Obviously it doesn't kill all of them, but there used to be even more of that kind of thing all the time. Library issues would basically get exported to its users, all basically due to language problems.