patito.Relation.with_columns

Relation.with_columns(**named_projections)

Return relations with additional columns.

If the provided columns expressions already exists as a column on the relation, the given column is overwritten.

Parameters

named_projections (Union[str, int, float]) – A set of column expressions, where the keyword is used as the column name, while the right-hand argument is a valid SQL expression.

Return type

Relation

Returns

Relation with the given columns appended, or possibly overwritten.

Examples

>>> import patito as pt
>>> db = pt.Database()
>>> relation = db.to_relation("select 1 as a, 2 as b")
>>> relation.with_columns(c="a + b").to_df()
shape: (1, 3)
┌─────┬─────┬─────┐
│ a   ┆ b   ┆ c   │
│ --- ┆ --- ┆ --- │
│ i64 ┆ i64 ┆ i64 │
╞═════╪═════╪═════╡
│ 1   ┆ 2   ┆ 3   │
└─────┴─────┴─────┘