Handle something like `filter{|row| row.a > 2 && row.b.nil? }`

[turnon]

Shall we add such feature ?

convert:

filter{|row| row.a > 2 && row.b.nil? }

to:

filter((Polars.col("a") > 2) & (Polars.col("b").is_null))

I just think it more like usual ruby code....