pub fn name_columns(
lf: LazyFrame,
header: Option<&[String]>,
) -> PolarsResult<LazyFrame>Expand description
lf with its columns named as shown_names says. Nothing is read: Polars has
the schema from the scan’s own inference.
With header, a file with nothing after its header lines (a log with no rows yet)
is a table with those columns and no rows, as Polars reads a file that is only a
header; Polars itself finds no data past the lines it skipped.