polars.Expr.alias#

Expr.alias(name: str) → Self[source]#

Rename the output of an expression.

Parameters:

name: New name.

See also

map_alias
prefix
suffix

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 │
└─────┴──────┘