DataFrame.pivot

DataFrame pivot(string[]  index,  string on,  string[]  values,
          PivotAgg agg =  PivotAgg.NONE)

Pivots the frame wide: the distinct values of on become columns, the distinct index tuples become rows, and the cells hold the values aggregated per (index tuple, on value) - first-appearance order everywhere, duplicate cells error under the default NONE, missing cells take the aggregate's empty-set value (ADR-2026-10-24-20; the full contract lives on ddn.df.reshape.pivot). Eager-only: lazy users collect() first.

Parameters

`index`	the row-key columns (empty: one aggregate row)
`on`	the column whose distinct values become columns
`values`	the cell columns (one or more)
`agg`	the duplicate-cell policy

Returns

the pivoted frame.

Throws

DataFrameException for absent columns, no value

columns, duplicate cells under NONE, or generated name collisions.