dfr arg-true
for dataframe
Returns indexes where values are true.
Signature
> dfr arg-true
Examples
Returns indexes where values are true
> [false true false] | dfr into-df | dfr arg-true
╭───┬──────────╮
│ # │ arg_true │
├───┼──────────┤
│ 0 │ 1 │
╰───┴──────────╯