polars.Expr.all method description is unclear on ignore_nulls parameter logic

[fci525]

Description

Documentation says:

If set to False, Kleene logic is used to deal with nulls: if the column contains any null values and no True values, the output is null.

This is immediately suspect in the example provided, where column c, containing None and True values, returns null. Also, a column containing only null values could be said to "contain no True values", but would produce an error since the method expects the series type to be Boolean and not null.

The stated logic is also not consistent with the documentation's linked article on Kleene logic. However, in testing, the actual method's behavior is consistent. Perhaps it would be more correct to say:

If set to False, Kleene logic is used to deal with nulls: if the column contains only True values, the output is true, while if it contains any False values, the output is false. If it contains only null and True values, the output is null.

Link

https://docs.pola.rs/api/python/stable/reference/expressions/api/polars.Expr.all.html#polars.Expr.all