I've never understood returns (https://github.com/dry-python/returns), is it just a gimmick or do people actually use it? It seems like it would be awkward to use and is working against how the language was designed.

[–] [email protected] 2 points 1 year ago

I don't use this library, but one I wrote myself with maybes, eithers, validators, and various other monads in production code.

While not pythonic, I don't think its a gimmick. I allow my junior engineers to write imperative and we will pair program to convert it to use monad structures like the ones in this library. We tend to find a lot of bugs and reduce the lines of code.

While we could probably clean up their imperative code to remove bugs and duplicated logic, but I find using monad chains makes it easier to find abstractions.

Data validation and error handling probably net the most return on investment in my experience. Simply return a left at some unit of code and handle it at the end of the chain.

[–] o11c 1 points 1 year ago (1 children)

I'm increasingly convinced that Python/JS-style duck typing is always a mistake, since you can't do default function impls for traits. Just use inheritance.

Rust's enums are even weirder, since they mix structuring with discrimination. You end up having to write everything twice most of the time. Again, use inheritance, though you'll have to choose between if chains and virtual function calls.

Python's pathlib has a major footgun in that ./foo collapses to foo, negating the main point of writing it that way in the first place.

[–] DanCardin 1 points 1 year ago

More obnoxiously than that even, imo, it’s that pathlib removes trailing slashes. Its impossible (afaict) to reproduce path.join(‘a’, ‘b/‘) with pathlib