polars.Expr.gather#
- Expr.gather( ) Expr [source]#
Take values by index.
- Parameters:
- indices
An expression that leads to a UInt32 dtyped Series.
- Returns:
- Expr
Expression of the same data type.
See also
Expr.get
Take a single value
Examples
>>> df = pl.DataFrame( ... { ... "group": [ ... "one", ... "one", ... "one", ... "two", ... "two", ... "two", ... ], ... "value": [1, 98, 2, 3, 99, 4], ... } ... ) >>> df.group_by("group", maintain_order=True).agg( ... pl.col("value").gather([2, 1]) ... ) shape: (2, 2) ┌───────┬───────────┐ │ group ┆ value │ │ --- ┆ --- │ │ str ┆ list[i64] │ ╞═══════╪═══════════╡ │ one ┆ [2, 98] │ │ two ┆ [4, 99] │ └───────┴───────────┘