> For the complete documentation index, see [llms.txt](https://docs-v3.toucantoco.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs-v3.toucantoco.com/data-management-in-datahub/datasets-in-toucan/preparing-data/overview-of-youprep-tm/column-header/duplicate-column.md).

# Duplicate column

The Duplicate column step enables you to duplicate a specific column. The duplicated column will be added to the end of the dataset.

### Step parameters

* `Duplicate column...` **column(string)\***: the column to duplicate
* `new column name` **string\***: Set a name for the duplicated column.

### Example

**Input**

<figure><img src="/files/G0b4omOHnutU2ynyiZQb" alt=""><figcaption><p>Column header - duplicate column input</p></figcaption></figure>

**Configuration**

```json
{
    "column": "Value",
    "new_column_name": "Value_duplicate"
}
```

**Output**

<figure><img src="/files/LEXIPTAjFEZZOO6PNjjK" alt=""><figcaption><p>Column header - duplicate column output</p></figcaption></figure>

{% hint style="warning" %}
an error will be raised if you try to set a name that is already used for another column.
{% endhint %}


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