polars n-unique for dataframe

Counts unique values.

Signature

> polars n-unique {flags}

Input/output types:

inputoutput
anyany

Examples

Counts unique values

> [1 1 2 2 3 3 4] | polars into-df | polars n-unique
╭───┬──────────────╮
 # │ count_unique │
├───┼──────────────┤
 0            4
╰───┴──────────────╯

Creates a is n-unique expression from a column

> polars col a | polars n-unique