dfr is-null for dataframe

Creates mask where value is null.

Signature

> dfr is-null

Input/output types:

input	output
any	any

Examples

Create mask where values are null

> let s = ([5 6 0 8] | dfr into-df);
    let res = ($s / $s);
    $res | dfr is-null
╭───┬─────────╮
│ # │ is_null │
├───┼─────────┤
│ 0 │ false   │
│ 1 │ false   │
│ 2 │ true    │
│ 3 │ false   │
╰───┴─────────╯

Creates a is null expression from a column

> dfr col a | dfr is-null

Tips: Dataframe commands were not shipped in the official binaries by default, you have to build it with --features=dataframe flag