Error on extraneous columns

[ion-elgreco]

Not sure if this exists, but when I do validate, it doesn't throw an error on extraneous columns. This was a feature in patito for example

[borchero]

This is intended. Other than this is the behavior in patito: would you have expected dataframely to keep the columns as well? If so, what would be your use case?

[ion-elgreco]

So using the return value of validate removes the columns, but we were only using it to see if there were errors, so we just wanted to receive an error if there are extra columns

[Makiv1]

It feels like there should at least be option to raise when calling .validate on a dataframe with columns not present in the dataframely schema.

One use of dataframely could be to monitor for schema drift of external sources. Say an external source adds another column, you might want to be notified that such a change has occurred. Dataframely could be the perfect tool for that.

Also out of curiosity, what is the reason for not raising when extra columns exist? It feels to me at least that this choice goes against the polars philosophy of "Adhering to a strict schema". For example polars will not allow you to concatenate two dataframes with different columns unless you explicitly set how="diagonal". It is possible that two dataframes - which have both been validated by the same schema - cause an exception in a call to pl.concat() (unless how="diagonal")

Super big fan of dataframely btw, You guys are doing some awesome work. :3