.. _auto_dataset_group_by:

*DATASET GROUP BY*
==================

Groups a dataset by one or more columns, annotating each resulting row with a configurable group label and column prefix. Use this worker to split or tag a flat dataset into labelled groups for downstream aggregation, filtering, or ML pipelines.

When to use
-----------

Classification: **process**.

Tagged: ``aggregation``, ``dataset``, ``group_by``, ``label``, ``split``, ``transform``.

Inputs
------

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   :header-rows: 1
   :widths: 20 20 20 20 20 20

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Choose Dataset
     - dataset
     - dataset
     - —
     - 
     - Input dataset to be grouped; accepts any tabular dataset available on the platform — leave empty only if the dataset is injected by an upstream worker.
   * - Group By
     - groupby
     - scalar
     - unclassified
     - 
     - One or more column names (multi-select, drawn from the input dataset) whose unique value combinations define the groups; defaults to 'unclassified' when no column is selected.
   * - Column Prefix
     - col_prefix
     - text
     - group_
     - 
     - String prefix prepended to each generated group-identifier column name (e.g. 'group_' produces 'group_0', 'group_1', …); defaults to 'group_'.
   * - Column Name
     - column_name
     - text
     - group
     - 
     - Base name for the new column that stores the group label assigned to each row; defaults to 'group'.

Outputs
-------

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   :header-rows: 1
   :widths: 20 20 20 20

   * - Label
     - ID
     - Type
     - Description
   * - dataset_group_by_output_1
     - dataset_group_by_output_1
     - dataset
     - Transformed dataset identical in rows to the input but augmented with a group-label column (named per column_name/col_prefix) that identifies which group each row belongs to.

Disciplines
-----------

- data.dataset.transform

Runnable example
----------------

A runnable example is registered for this worker. Open the example workflow on the d3VIEW canvas: `/api/workflow/example?id=dataset_group_by <https://www.d3view.com/api/workflow/example?id=dataset_group_by>`_

.. raw:: html

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   <p style="font-size:11px;color:#888">
   Auto-generated from <code>transformation</code> schema. Worker id: <code>dataset_group_by</code>. Schema hash: <code>5ad596e651c2</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>