polars.LazyFrame.with_columns#

LazyFrame.with_columns(exprs: Optional[Union[Expr, Series, Sequence[polars.internals.expr.expr.Expr | polars.internals.series.series.Series]]] = None, **named_exprs: polars.internals.expr.expr.Expr | polars.internals.series.series.Series | str) → LDF[source]#

Add or overwrite multiple columns in a DataFrame.

Parameters:

exprs: List of Expressions that evaluate to columns.
**named_exprs: Named column Expressions, provided as kwargs.

Examples

>>> ldf = pl.DataFrame(
...     {
...         "a": [1, 2, 3, 4],
...         "b": [0.5, 4, 10, 13],
...         "c": [True, True, False, True],
...     }
... ).lazy()
>>> ldf.with_columns(
...     [
...         (pl.col("a") ** 2).alias("a^2"),
...         (pl.col("b") / 2).alias("b/2"),
...         (pl.col("c").is_not()).alias("not c"),
...     ]
... ).collect()
shape: (4, 6)
┌─────┬──────┬───────┬──────┬──────┬───────┐
│ a   ┆ b    ┆ c     ┆ a^2  ┆ b/2  ┆ not c │
│ --- ┆ ---  ┆ ---   ┆ ---  ┆ ---  ┆ ---   │
│ i64 ┆ f64  ┆ bool  ┆ f64  ┆ f64  ┆ bool  │
╞═════╪══════╪═══════╪══════╪══════╪═══════╡
│ 1   ┆ 0.5  ┆ true  ┆ 1.0  ┆ 0.25 ┆ false │
├╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┤
│ 2   ┆ 4.0  ┆ true  ┆ 4.0  ┆ 2.0  ┆ false │
├╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┤
│ 3   ┆ 10.0 ┆ false ┆ 9.0  ┆ 5.0  ┆ true  │
├╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┤
│ 4   ┆ 13.0 ┆ true  ┆ 16.0 ┆ 6.5  ┆ false │
└─────┴──────┴───────┴──────┴──────┴───────┘

>>> # Support for kwarg expressions is considered EXPERIMENTAL.
>>> # Currently requires opt-in via `pl.Config` boolean flag:
>>>
>>> pl.Config.with_columns_kwargs = True
>>> ldf.with_columns(
...     d=pl.col("a") * pl.col("b"),
...     e=pl.col("c").is_not(),
...     f="foo",
... ).collect()
shape: (4, 6)
┌─────┬──────┬───────┬──────┬───────┬─────┐
│ a   ┆ b    ┆ c     ┆ d    ┆ e     ┆ f   │
│ --- ┆ ---  ┆ ---   ┆ ---  ┆ ---   ┆ --- │
│ i64 ┆ f64  ┆ bool  ┆ f64  ┆ bool  ┆ str │
╞═════╪══════╪═══════╪══════╪═══════╪═════╡
│ 1   ┆ 0.5  ┆ true  ┆ 0.5  ┆ false ┆ foo │
├╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌┤
│ 2   ┆ 4.0  ┆ true  ┆ 8.0  ┆ false ┆ foo │
├╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌┤
│ 3   ┆ 10.0 ┆ false ┆ 30.0 ┆ true  ┆ foo │
├╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌┤
│ 4   ┆ 13.0 ┆ true  ┆ 52.0 ┆ false ┆ foo │
└─────┴──────┴───────┴──────┴───────┴─────┘