polars filter-with for [dataframe or lazyframe](/commands/categories/dataframe or lazyframe.md)
Filters dataframe using a mask or expression as reference.
This command requires a plugin
The polars filter-with 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 filter-with {flags} (mask or expression)
Parameters
mask or expression: boolean mask used to filter data
Input/output types:
| input | output |
|---|---|
| polars_dataframe | polars_dataframe |
| polars_lazyframe | polars_lazyframe |
Examples
Filter dataframe using a bool mask
> let mask = ([true false] | polars into-df);
[[a b]; [1 2] [3 4]] | polars into-df | polars filter-with $mask
╭───┬───┬───╮
│ # │ a │ b │
├───┼───┼───┤
│ 0 │ 1 │ 2 │
╰───┴───┴───╯Filter dataframe using an expression
> [[a b]; [1 2] [3 4]] | polars into-df | polars filter-with ((polars col a) > 1)
╭───┬───┬───╮
│ # │ a │ b │
├───┼───┼───┤
│ 0 │ 3 │ 4 │
╰───┴───┴───╯