polars shift

For [dataframe or lazyframe](/commands/categories/dataframe or lazyframe.md).

Shifts the values by a given period.

warning This command requires a plugin The polars shift 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.

Command Type

plugin

Signature

> polars shift {flags} (period)

Flags

--fill, -f {any}: Expression used to fill the null values (lazy df).

Parameters

period: Shift period.

Input/output types:

input	output
polars_dataframe	polars_dataframe
polars_lazyframe	polars_lazyframe
polars_expression	polars_expression
polars_selector	polars_expression

Examples

Shifts the values by a given period

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

Shifts the values by a given period, fill absent values with 0

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

Shift values of a column, fill absent values with 0

> [[a]; [1] [2] [2] [3] [3]]
                    | polars into-lazy
                    | polars with-column {b: (polars col a | polars shift 2 --fill 0)}
                    | polars collect
╭───┬───┬───╮
│ # │ a │ b │
├───┼───┼───┤
│ 0 │ 1 │ 0 │
│ 1 │ 2 │ 0 │
│ 2 │ 2 │ 1 │
│ 3 │ 3 │ 2 │
│ 4 │ 3 │ 2 │
╰───┴───┴───╯

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