polars.Series.to_dummies

Series.to_dummies(
    *,
    separator: str_ = '_',
    drop_first: bool = False,
    drop_nulls: bool = False,
) → DataFrame

Get dummy/indicator variables.

Parameters:

separator

Separator/delimiter used when generating column names.

drop_first

Remove the first category from the variable being encoded.

drop_nulls

If there are None values in the series, a null column is not generated. Null values in the input are represented by zero vectors.

Examples

>>> s = pl.Series("a", [1, 2, 3])
>>> s.to_dummies()
shape: (3, 3)
┌─────┬─────┬─────┐
│ a_1 ┆ a_2 ┆ a_3 │
│ --- ┆ --- ┆ --- │
│ u8  ┆ u8  ┆ u8  │
╞═════╪═════╪═════╡
│ 1   ┆ 0   ┆ 0   │
│ 0   ┆ 1   ┆ 0   │
│ 0   ┆ 0   ┆ 1   │
└─────┴─────┴─────┘

>>> s.to_dummies(drop_first=True)
shape: (3, 2)
┌─────┬─────┐
│ a_2 ┆ a_3 │
│ --- ┆ --- │
│ u8  ┆ u8  │
╞═════╪═════╡
│ 0   ┆ 0   │
│ 1   ┆ 0   │
│ 0   ┆ 1   │
└─────┴─────┘

>>> s = pl.Series("a", [1, 2, None, 3])
>>> s.to_dummies(drop_nulls=True, drop_first=True)
shape: (4, 2)
┌─────┬─────┐
│ a_2 ┆ a_3 │
│ --- ┆ --- │
│ u8  ┆ u8  │
╞═════╪═════╡
│ 0   ┆ 0   │
│ 1   ┆ 0   │
│ 0   ┆ 0   │
│ 0   ┆ 1   │
└─────┴─────┘