polars.Expr.list.unique#

Expr.list.unique(*, maintain_order: bool = False) → Expr[source]#

Get the unique/distinct values in the list.

Parameters:

maintain_order: Maintain order of data. This requires more work.

Examples

>>> df = pl.DataFrame(
...     {
...         "a": [[1, 1, 2]],
...     }
... )
>>> df.with_columns(unique=pl.col("a").list.unique())
shape: (1, 2)
┌───────────┬───────────┐
│ a         ┆ unique    │
│ ---       ┆ ---       │
│ list[i64] ┆ list[i64] │
╞═══════════╪═══════════╡
│ [1, 1, 2] ┆ [1, 2]    │
└───────────┴───────────┘