hash list of String

[gab23r]

Description

I am maybe not the first to ask for this feature, but I couldn't find anything.

I which I could hash a list of string with polars. Is it out of the scope ?
It would be awesome to be able to hash any nested polars data types.

pl.DataFrame({
    'a': [['1', '2']],
}).select(pl.col('a').hash())
# PanicException: Hashing a list with a non-numeric inner type not supported. Got dtype: List(String)

[ion-elgreco]

You can hash the inner elements first with list.eval(pl.element().hash).hash()

[gab23r]

Thanks @ion-elgreco, this is a workaround, I think the feature is still really valuable. Today if you want to hash a full dataframe with hash_rows for example, It may fail for certain data types. So you have to handle these cases by hand.

[ion-elgreco]

I agree :) Just showcasing a workaround that might help

[cmdlineluser]

I think it has been mentioned a few times with regards to .group_by

Another workaround is to .cast(pl.List(pl.Categorical))

Not sure on the technical reasons for why it is disallowed currently.

[reswqa]

I think this is duplicated with #10747.