[zahlman]

Argument parsing is absolutely the kind of thing where I'd reach for a third-party library if the standard library didn't provide (and in Python's case, maybe even then - argparse has some really unpleasant behaviours). When you look through library code, it might seem like way more than you'd write yourself, and it probably is. But on a conceptual level you'll probably actually end up using a big chunk of it, or at least see a future use for it. And it doesn't tend to pull in a lot of dependencies. (For example, click only needs colorama, and then only on Windows; and that doesn't appear to bring in anything transitively.)

It's a very different story with heavyweight dependencies like Numpy (which include reams of tests, documentation and headers even in the wheels that people are only installing to be a dependency of something else, and covers a truly massive range of functionality including exposing BLAS and LAPACK for people who might just want to multiply some small matrices or efficiently represent an image bitmap), or the more complex ones that end up bringing in multiple things completely unrelated to your project that will never be touched at runtime. (Rich supports a ton of wide-ranging things people might want to do with text in a terminal, and I would guess most clients probably want to do exactly one of those things.)