ReducedGroupBy

An intermediate class used in GroupBy reducing operations.

Serves as a transitional step between performing a reduction on groups and specifying how the resulting reduced rows should be represented in a new DataFrame.

Available transformation methods:

• concat — concatenates all reduced rows into a single DataFrame;

• values — creates a DataFrame with new rows by transforming each reduced row using ColumnsForAggregateSelectionDsl;

• into — creates a new column with values computed using a RowExpression for each row, or a new column group containing each group reduced to a single row.

Each method returns a new DataFrame that includes the grouping key columns, containing all unique grouping key values (or value combinations for multiple keys) together with their corresponding reduced rows.

See also: GroupBy grammar.

For more information: See "GroupBy Reducing" on the documentation website.