polars.Expr.arg_unique

Expr.arg_unique() → Self

Get index of first unique value.

Examples

>>> df = pl.DataFrame(
...     {
...         "a": [8, 9, 10],
...         "b": [None, 4, 4],
...     }
... )
>>> df.select(pl.col("a").arg_unique())
shape: (3, 1)
┌─────┐
│ a   │
│ --- │
│ u32 │
╞═════╡
│ 0   │
│ 1   │
│ 2   │
└─────┘
>>> df.select(pl.col("b").arg_unique())
shape: (2, 1)
┌─────┐
│ b   │
│ --- │
│ u32 │
╞═════╡
│ 0   │
│ 1   │
└─────┘