I tried loading a partitioned asset value with

load_asset_value

without specifying a partition, and got a very unhelpful error. I think the function tried to load the parent directory containing the partitioned asset with pickle as though it was the pickled file, giving me an unhelpful

IsADirectoryError

. I eventually realized the problem was I wasn't specifying a

partition_key

. It would be helpful if, in a case like this, the error message told me explicitly to supply a partition key for a partitioned asset, rather than leave it to the lower level pathlib to throw an error that doesn't explain what I did wrong.

Thanks for the feedback! Yeah, that does sound like an unhelpful error. I'll bring it back to the team. Thanks for trying out

load_asset_value

! It's one of my favorite hidden gems of Dagster.

Yeah, seems like a really nice feature.