polars.Expr.sample#

Expr.sample(
n: int | IntoExprColumn | None = None,
*,
fraction: float | IntoExprColumn | None = None,
with_replacement: bool = False,
shuffle: bool = False,
seed: int | None = None,
) → Self[source]#

Sample from this expression.

Parameters:
n

Number of items to return. Cannot be used with fraction. Defaults to 1 if fraction is None.

fraction

Fraction of items to return. Cannot be used with n.

with_replacement

Allow values to be sampled more than once.

shuffle

Shuffle the order of sampled data points.

seed

Seed for the random number generator. If set to None (default), a random seed is generated for each sample operation.

Examples

>>> df = pl.DataFrame({"a": [1, 2, 3]})
>>> df.select(pl.col("a").sample(fraction=1.0, with_replacement=True, seed=1))
shape: (3, 1)
┌─────┐
│ a   │
│ --- │
│ i64 │
╞═════╡
│ 3   │
│ 1   │
│ 1   │
└─────┘