dataframe

Create a var expression for an aggregation.

This command requires a plugin

The polars var command resides in the polars plugin. To use this command, you must install and register nu_plugin_polars. See the Plugins chapter in the book for more information.

Signature

> polars var {flags}

Input/output types:

input	output
any	any

Examples

Var value from columns in a dataframe or aggregates columns to their var value

> [[a b]; [6 2] [4 2] [2 2]] | polars into-df | polars var | polars collect
╭───┬──────┬──────╮
│ # │  a   │  b   │
├───┼──────┼──────┤
│ 0 │ 4.00 │ 0.00 │
╰───┴──────┴──────╯

Var aggregation for a group-by

> [[a b]; [one 2] [one 2] [two 1] [two 1]]
                    | polars into-df
                    | polars group-by a
                    | polars agg (polars col b | polars var)
                    | polars collect
                    | polars sort-by a
╭───┬─────┬──────╮
│ # │  a  │  b   │
├───┼─────┼──────┤
│ 0 │ one │ 0.00 │
│ 1 │ two │ 0.00 │
╰───┴─────┴──────╯