you have map_elements in polars which does exactly this. https://docs.pola.rs/api/python/dev/reference/expressions/api/polars.Expr.map_elements.html https://do

you have map_elements in polars which does exactly this. https://docs.pola.rs/api/python/dev/reference/expressions/api/polars.Expr.map_elements.html https://docs.pola.rs/api/python/dev/reference/expressions/ap... You can also iter_rows into a lambda if you really want to. https://docs.pola.rs/api/python/stable/reference/dataframe/api/polars.DataFrame.iter_rows.html https://docs.pola.rs/api/python/stable/reference/dataframe/a... Personally I find it extremely rare that I need to do this given Polars expressions are so comprehensive, including when.then.otherwise when all else fails.