polars.Expr.repeat_by#

Expr.repeat_by(by: polars.internals.expr.expr.Expr | str) → Expr[source]#

Repeat the elements in this Series as specified in the given expression.

The repeated elements are expanded into a List.

Parameters:

by: Numeric column that determines how often the values will be repeated. The column will be coerced to UInt32. Give this dtype to make the coercion a no-op.

Returns:

Series of type List

Examples

>>> df = pl.DataFrame(
...     {
...         "a": ["x", "y", "z"],
...         "n": [1, 2, 3],
...     }
... )
>>> df.select(pl.col("a").repeat_by("n"))
shape: (3, 1)
┌─────────────────┐
│ a               │
│ ---             │
│ list[str]       │
╞═════════════════╡
│ ["x"]           │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┤
│ ["y", "y"]      │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┤
│ ["z", "z", "z"] │
└─────────────────┘