polars.Expr.keep_name#
- Expr.keep_name() Self [source]#
Keep the original root name of the expression.
Examples
>>> df = pl.DataFrame( ... { ... "a": [1, 2], ... "b": [3, 4], ... } ... )
Keep original column name to undo an alias operation.
>>> df.with_columns([(pl.col("a") * 9).alias("c").keep_name()]) shape: (2, 2) ┌─────┬─────┐ │ a ┆ b │ │ --- ┆ --- │ │ i64 ┆ i64 │ ╞═════╪═════╡ │ 9 ┆ 3 │ │ 18 ┆ 4 │ └─────┴─────┘
Prevent “DuplicateError: Column with name: ‘literal’ has more than one occurrences” errors.
>>> df.select((pl.lit(10) / pl.all()).keep_name()) shape: (2, 2) ┌──────┬──────────┐ │ a ┆ b │ │ --- ┆ --- │ │ f64 ┆ f64 │ ╞══════╪══════════╡ │ 10.0 ┆ 3.333333 │ │ 5.0 ┆ 2.5 │ └──────┴──────────┘