> 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/text/extract-substring.md).

# Extract substring

The Extract substring allows to to exctract a sustring of characters in a text column

### Step parameters

* `Extract a substring from...` : tThe text column you need to extract a substring from
* `Substring starts at character position`: the position of the first character of the substring you want to extract. (1-based)
* `And ends at character position` : the position of the last character of the sustring you want to extract. (-1 for all remaining)
* `New column name` (optional): Enter a custom name for the new column that will contain the extracted substring

### Example

**Input**

<figure><img src="/files/yu3BCgm8fpsNSMOQrHPO" alt=""><figcaption><p>Extract substring - input</p></figcaption></figure>

**Configuration**

```json
{
    "column": "full_text"
    "start_index": "1",
    "end_index": "5",
    "new_column_name": "substring_result"
}
```

**Result**

<figure><img src="/files/UAyiMDojFKKKBSpjiYbB" alt=""><figcaption><p>extract substring - result</p></figcaption></figure>

{% hint style="info" %}
The character positions are integers that can be either positive (starting at 1 for the first character of the original string) or negative (starting at -1 for the last character of the original string). The can never be equal to 0.

The character position of the last character of the substring should always refer to a character position higher than the first character of the substring. If not, you will get a backend error.

use negative character positions when you need to count characters from the end of the original string.
{% endhint %}


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