polars horizontal for expression

Horizontal calculation across multiple columns.

This command requires a plugin

The polars horizontal 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 horizontal {flags} (type) ...rest

Flags

  • --nulls, -n: If set, null value in the input will lead to null output

Parameters

  • type: horizontal operation. Values of all, any, min, max, sum, and mean are accepted.
  • ...rest: Expression(s) that define the lazy group-by

Input/output types:

inputoutput
anyexpression

Examples

Horizontal sum across two columns (ignore nulls by default)

> [[a b]; [1 2] [2 3] [3 4] [4 5] [5 null]]
                    | polars into-df
                    | polars select (polars horizontal sum a b)
                    | polars collect
╭───┬─────╮
│ # │ sum │
├───┼─────┤
│ 0 │   3 │
│ 1 │   5 │
│ 2 │   7 │
│ 3 │   9 │
│ 4 │   5 │
╰───┴─────╯

Horizontal sum across two columns while accounting for nulls

> [[a b]; [1 2] [2 3] [3 4] [4 5] [5 null]]
                    | polars into-df
                    | polars select (polars horizontal sum a b --nulls)
                    | polars collect
╭───┬─────╮
│ # │ sum │
├───┼─────┤
│ 0 │   3 │
│ 1 │   5 │
│ 2 │   7 │
│ 3 │   9 │
│ 4 │     │
╰───┴─────╯