polars.Expr.inspect#
- Expr.inspect(fmt: str = '{}') Expr [source]#
Print the value that this expression evaluates to and pass on the value.
Examples
>>> df = pl.DataFrame({"foo": [1, 1, 2]}) >>> df.select(pl.col("foo").cum_sum().inspect("value is: {}").alias("bar")) value is: shape: (3,) Series: 'foo' [i64] [ 1 2 4 ] shape: (3, 1) ┌─────┐ │ bar │ │ --- │ │ i64 │ ╞═════╡ │ 1 │ │ 2 │ │ 4 │ └─────┘