polars.Expr.sample#

Expr.sample( n: int | None = None, *, fraction: float | None = None, with_replacement: bool = False, shuffle: bool = False, seed: int | None = None, fixed_seed: bool = False, ) → 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 using the random module.
fixed_seed: If True, The seed will not be incremented between draws. This can make output predictable because draw ordering can change due to threads being scheduled in a different order.

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   │
└─────┘