polars fill-null for lazyframe

Replaces NULL values with the given expression.

This command requires a plugin

The polars fill-null 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 fill-null {flags} (fill)

Parameters

  • fill: Expression to use to fill the null values

Input/output types:

inputoutput
dataframedataframe
expressionexpression

Examples

Fills the null values by 0

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

Fills the null values in expression

> [[a]; [1] [2] [2] [3] [3]]
                    | polars into-df
                    | polars select (polars col a | polars shift 2 | polars fill-null 0)
                    | polars collect
╭───┬───╮
│ # │ a │
├───┼───┤
│ 0 │ 0 │
│ 1 │ 0 │
│ 2 │ 1 │
│ 3 │ 2 │
│ 4 │ 2 │
╰───┴───╯