.. _auto_dataset_keep_columns:

*DATASET KEEP COLUMNS*
======================

Filters a dataset down to a specified subset of columns, discarding all others. Provide the input dataset and a comma-separated list (or regex-style selection) of column names to retain; the resulting dataset contains only those columns in their original order.

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

Classification: **process**.

Tagged: ``column_filter``, ``dataset``, ``keep_columns``, ``projection``, ``subset``.

Inputs
------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20 20 20

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Dataset
     - dataset_1
     - dataset
     - —
     - 
     - The source dataset whose columns will be filtered; accepts any tabular dataset object available in the workflow.
   * - CSV Column Names
     - column_names_regex
     - scalar
     - —
     - 
     - Comma-separated list of column names (or regex patterns) to retain from the dataset; columns not matched are dropped. Leave blank to pass all columns through unchanged.

Outputs
-------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20

   * - Label
     - ID
     - Type
     - Description
   * - dataset_keep_columns_output_1
     - dataset_keep_columns_output_1
     - dataset
     - Filtered dataset containing only the columns specified in CSV Column Names, preserving the original row order and data types.

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_keep_columns <https://www.d3view.com/api/workflow/example?id=dataset_keep_columns>`_

.. raw:: html

   <hr style="margin-top:2em">
   <p style="font-size:11px;color:#888">
   Auto-generated from <code>transformation</code> schema. Worker id: <code>dataset_keep_columns</code>. Schema hash: <code>92c80e594937</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>