polars when for expression
Creates and modifies a when expression.
Signature
> polars when {flags} (when expression) (then expression)
Parameters
-
when expression: When expression used for matching. -
then expression: Expression that will be applied when predicate is true.
Input/output types:
| input | output |
|---|---|
| nothing | polars_expression |
| polars_expression | polars_expression |
| any | polars_expression |
Examples
Create a when conditions
> polars when ((polars col a) > 2) 4
Create a when conditions
> polars when ((polars col a) > 2) 4 | polars when ((polars col a) < 0) 6
Create a new column for the dataframe
> [[a b]; [6 2] [1 4] [4 1]]
| polars into-lazy
| polars with-column (
polars when ((polars col a) > 2) 4 | polars otherwise 5 | polars as c
)
| polars with-column (
polars when ((polars col a) > 5) 10 | polars when ((polars col a) < 2) 6 | polars otherwise 0 | polars as d
)
| polars collect
╭───┬───┬───┬───┬────╮
│ # │ a │ b │ c │ d │
├───┼───┼───┼───┼────┤
│ 0 │ 6 │ 2 │ 4 │ 10 │
│ 1 │ 1 │ 4 │ 5 │ 6 │
│ 2 │ 4 │ 1 │ 4 │ 0 │
╰───┴───┴───┴───┴────╯
Copyright © 2019–2026 The Nushell Project DevelopersLicensed under the MIT License.
https://www.nushell.sh/commands/docs/polars_when.html
