---
title: "MapModel[T, U]"
---
import XRef from "../../../../components/XRef.astro";
import Signature from "../../../../components/Signature.astro";

```python
from slint import MapModel
```

MapModel is a read-only <XRef to="Model" /> that provides the rows of a source model,
each passed through a map function.

The MapModel follows the changes of the source model.

```python
names = slint.ListModel([("Hans", "Emil"), ("Max", "Mustermann")])
full_names = slint.MapModel(names, lambda name: f"{name[1]}, {name[0]}")
assert full_names[0] == "Emil, Hans"
```

Alternatively, subclass MapModel and implement `map_row`:

```python
class FullNames(slint.MapModel[tuple[str, str], str]):
    def map_row(self, row_data: tuple[str, str]) -> str:
        return f"{row_data[1]}, {row_data[0]}"

full_names = FullNames(names)
```

**Bases:** _AdapterModel&#91;U&#93;

## Properties

### source_model

<Signature symbol="slint.models.MapModel.source_model">source_model</Signature>

## Methods

### map_row

<Signature symbol="slint.models.MapModel.map_row">map_row(row_data: T) -&gt; U</Signature>

Returns the row of this model for `row_data`, a row of the source model.
Re-implement this method in a sub-class that doesn't pass a map function
to the constructor.

### notify_row_changed

<Signature symbol="slint.models.Model.notify_row_changed">notify_row_changed(row: <XRef to="int" plain />) -&gt; <XRef to="None" plain /></Signature>

Call this method from a sub-class to notify the views that a row has changed.

### notify_row_removed

<Signature symbol="slint.models.Model.notify_row_removed">notify_row_removed(row: <XRef to="int" plain />, count: <XRef to="int" plain />) -&gt; <XRef to="None" plain /></Signature>

Call this method from a sub-class to notify the views that
`count` rows have been removed starting at `row`.

### notify_row_added

<Signature symbol="slint.models.Model.notify_row_added">notify_row_added(row: <XRef to="int" plain />, count: <XRef to="int" plain />) -&gt; <XRef to="None" plain /></Signature>

Call this method from a sub-class to notify the views that
`count` rows have been added starting at `row`.

### set_row_data

<Signature symbol="slint.models.Model.set_row_data">set_row_data(row: <XRef to="int" plain />, value: T) -&gt; <XRef to="None" plain /></Signature>

Call this method on mutable models to change the data for the given row.
The UI will also call this method when modifying a model's data.
Re-implement this method in a sub-class to handle the change.

### row_count

<Signature symbol="slint.models._AdapterModel.row_count">row_count() -&gt; <XRef to="int" plain /></Signature>

### row_data

<Signature symbol="slint.models._AdapterModel.row_data">row_data(row: <XRef to="int" plain />) -&gt; T | None</Signature>

### push_row

<Signature symbol="slint.models.Model.push_row">push_row(value: T) -&gt; <XRef to="None" plain /></Signature>

Add a new row to the model with the provided value.
The default implementation calls `insert_row` with the row count.

### remove_row

<Signature symbol="slint.models.Model.remove_row">remove_row(row: <XRef to="int" plain />) -&gt; <XRef to="None" plain /></Signature>

Remove the row at the given index.
Raises an exception when the model rejects the modification.
The default implementation raises NotImplementedError. A model that
supports removing rows should also call `notify_row_removed`.

### insert_row

<Signature symbol="slint.models.Model.insert_row">insert_row(row: <XRef to="int" plain />, value: T) -&gt; <XRef to="None" plain /></Signature>

Insert a new row at the given index.
Raises an exception when the model rejects the modification.
The default implementation raises NotImplementedError. A model that
supports inserting rows should also call `notify_row_added`.