.. _auto_dataset_get_num_columns:

*DATASET GET NUM COLUMNS*
=========================

Counts and returns the number of columns in a given dataset. Use this worker whenever a downstream step needs to know the column width of a dataset at runtime, e.g. for dynamic branching or validation logic.

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

Classification: **process**.

Tagged: ``columns``, ``dataset``, ``inspection``, ``metadata``, ``shape``.

Inputs
------

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

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Dataset
     - dataset
     - dataset
     - —
     - 
     - The input dataset whose column count will be measured; accepts any tabular dataset object — leave empty only if the column count is not yet needed at this workflow stage.

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - Number of Columns
     - num_columns
     - scalar
     - Integer scalar representing the total number of columns present in the input dataset.

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

- data.dataset.transform
- data.statistics

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

A runnable example is registered for this worker. Open the example workflow on the d3VIEW canvas: `/api/workflow/example?id=dataset_get_num_columns <https://www.d3view.com/api/workflow/example?id=dataset_get_num_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_get_num_columns</code>. Schema hash: <code>9840a0eb0225</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>