polars count-null for dataframe

Counts null values.

Signature

> polars count-null {flags}

Input/output types:

inputoutput
anyany

Examples

Counts null values

> let s = ([1 1 0 0 3 3 4] | polars into-df);
    ($s / $s) | polars count-null
╭───┬────────────╮
 # │ count_null │
├───┼────────────┤
 0          2
╰───┴────────────╯