polars.Expr.alias

Expr.alias(name: str) polars.internals.expr.Expr

Rename the output of an expression.

Parameters
name

New name.

Examples

>>> df = pl.DataFrame(
...     {
...         "a": [1, 2, 3],
...         "b": ["a", "b", None],
...     }
... )
>>> df
shape: (3, 2)
┌─────┬──────┐
│ a   ┆ b    │
│ --- ┆ ---  │
│ i64 ┆ str  │
╞═════╪══════╡
│ 1   ┆ a    │
├╌╌╌╌╌┼╌╌╌╌╌╌┤
│ 2   ┆ b    │
├╌╌╌╌╌┼╌╌╌╌╌╌┤
│ 3   ┆ null │
└─────┴──────┘
>>> df.select(
...     [
...         pl.col("a").alias("bar"),
...         pl.col("b").alias("foo"),
...     ]
... )
shape: (3, 2)
┌─────┬──────┐
│ bar ┆ foo  │
│ --- ┆ ---  │
│ i64 ┆ str  │
╞═════╪══════╡
│ 1   ┆ a    │
├╌╌╌╌╌┼╌╌╌╌╌╌┤
│ 2   ┆ b    │
├╌╌╌╌╌┼╌╌╌╌╌╌┤
│ 3   ┆ null │
└─────┴──────┘