Hey folks, qq on config.when when matches against multiple config values. So if I have something like

@config.when(stage="training", imputation="median")  # type: ignore[misc]
def imputers__training__median(

What do I actually do about those dunders? It seems to be properly included into graph like this, but do we really need to enumerate all those values in the function name? Thanks!

Hi Konstantin! When you use

@config.when

to define two

imputers

nodes, you need to have functions named

imputers__SOMETHING()

and

imputers_SOMETHING_ELSE()

. What you put after the dunder is up to you (Hamilton doesn't read it). You could have

imputers__default()

,

imputers__v1()

,

imputers__training()

and organize it how you prefer

Alright, so basically anything after the dunder is for my own understanding and there is no expectation from the frameworks side what it is in there? I know I’m rehashing what you said, but just want to make sure I understand it right.

exactly!

This is quite a relief thanks!

Thanks @Thierry Jean! To add/confi — they should only have one set of dunders in them. Under the hood it’ll find the last

__

and remove that + everything after that, but I think it’s fair to assuem that multiple sets of

__

is closer to undefined behavior