polars agg for lazyframe

Performs a series of aggregations from a group-by.

This command requires a plugin

The polars agg 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 agg {flags} ...rest

Parameters

  • ...rest: Expression(s) that define the aggregations to be applied

Input/output types:

inputoutput
dataframedataframe

Examples

Group by and perform an aggregation

> [[a b]; [1 2] [1 4] [2 6] [2 4]]
                | polars into-lazy
                | polars group-by a
                | polars agg [
                    (polars col b | polars min | polars as "b_min")
                    (polars col b | polars max | polars as "b_max")
                    (polars col b | polars sum | polars as "b_sum")
                 ]
                | polars collect
                | polars sort-by a
╭───┬───┬───────┬───────┬───────╮
│ # │ a │ b_min │ b_max │ b_sum │
├───┼───┼───────┼───────┼───────┤
│ 0 │ 1 │     2 │     4 │     6 │
│ 1 │ 2 │     4 │     6 │    10 │
╰───┴───┴───────┴───────┴───────╯

Group by and perform an aggregation using a record

> [[a b]; [1 2] [1 4] [2 6] [2 4]]
                | polars into-lazy
                | polars group-by a
                | polars agg {
                    b_min: (polars col b | polars min)
                    b_max: (polars col b | polars max)
                    b_sum: (polars col b | polars sum)
                 }
                | polars collect
                | polars sort-by a
╭───┬───┬───────┬───────┬───────╮
│ # │ a │ b_min │ b_max │ b_sum │
├───┼───┼───────┼───────┼───────┤
│ 0 │ 1 │     2 │     4 │     6 │
│ 1 │ 2 │     4 │     6 │    10 │
╰───┴───┴───────┴───────┴───────╯