---
title: "system.dataset.setValue"
description: "Takes a dataset and returns a new dataset with one value altered."
---

# system.dataset.setValue

> Takes a dataset and returns a new dataset with one value altered.

This function is used in **Python Scripting**.

## Description

Takes a [dataset](platform/scripting/python-scripting/variables-datatypes-and-objects/datasets.md) and returns a new dataset with one value altered.

:::note
Datasets are immutable, which means they cannot be directly modified once created. Instead, this scripting function returns a new dataset with some modification applied, which must be assigned to a variable to be used. See [Altering a Dataset](platform/scripting/python-scripting/variables-datatypes-and-objects/datasets.md#altering-a-dataset).
:::

## Client Permission Restrictions
This scripting function has no [Client Permission](../../../ignition-modules/vision/vision-project-properties/vision-project-properties.md#vision-permissions-properties) restrictions.

## Syntax - columnName
`system.dataset.setValue(dataset, rowIndex, columnName, value)`

### Parameters
Type | Parameter | Description 
------- | ------- | ------- 
Dataset | `dataset` | The starting dataset. Will not be modified (datasets are immutable), but acts as the basis for the returned dataset.
Integer | `rowIndex` | The index of the row to set the value at (starting at 0).
String | `columnName` | The name of the column to set the value at. Case insensitive.
Any | `value` | The new value for the specified row/column.

### Returns
**Dataset** - A new dataset, with the new value set at the given location.

### Scope
Gateway, Vision Client, Perspective Session

## Syntax - columnIndex

`system.dataset.setValue(dataset, rowIndex, columnIndex, value)`

### Parameters
Type | Parameter | Description 
------- | ------- | ------- 
Dataset | `dataset` | The starting dataset. Will not be modified (datasets are immutable), but acts as the basis for the returned dataset.
Integer | `rowIndex` | The index of the row to set the value at (starting at 0).
Integer | `columnIndex` | The index of the column to set the value at (starting at 0)
Any | `value` | The new value for the specified row/column.

### Returns
**Dataset** - A new dataset, with the new value set at the given location.

### Scope
Gateway, Vision Client, Perspective Session

## Code Examples

```python title="Code Snippet"
# This snippet demonstrates how to take an initial dataset, set a new value on a new dataset, and then write back to the source of the initial dataset.
# In this case we're using a Table component from the Vision module.
# Fetch a reference to an existing dataset.
table = event.source.parent.getComponent("Table")
 
# Make a new dataset with an updated value
newData = system.dataset.setValue(table.data, 3, "lname", 7)
 
# Repalce the table's dataset with our new dataset
table.data = newData
```

```python title="Code Snippet"
# This snippet could be used for a Vision Button's actionPerformed event to change the selected cell's value in a Table component to zero.
# Fetch table reference
table = event.source.parent.getComponent("Table")
 
# Fetch selected row and column
selRow = table.getSelectedRow()
selCol = table.getSelectedColumn()
 
# If row and column have been selected, update value in table to 0.
if selRow != -1 and selCol != -1:
   newData = system.dataset.setValue(table.data, selRow, selCol, 0.0)
   table.data = newData
```