<!-- Source: https://docs.marimo.io/api/inputs/dropdown/ -->

# Dropdown

[Interactive marimo example](https://marimo.app/?embed=true&mode=edit&show-chrome=false#code/JYWwDg9gTgLgBCAhlUEBQixjgXgc1AOgEEsAKAd2ABMYALHAIhAFNrgBXERgSjTQACmMIQDGLADYS01FgDM4AfUVkeALjRwtcUJFj4UICHEQBnBOm1woLGBygA7QcLGTpshctUar1KBDBqCAoHXAtCDmBCPwCgkLIAmGAIB1McAG1GUjAJFlNGABo4RgB5KEQHAHM8wuKABRZkfIBdIolEACNJJlE6CAhTFjg5KEiYXk1tGMDgh0V2UXg8Iwio6biHBLAklLSAbyysXPy1AEYi0vKqmrUAJguGpsY1AGYAXwLJq2+f36sAN0QEg4LCY2WOtQAxDoHMAkkC4IDgSwvn80X92l0JD0+gMhiMxnAqPQ4At4IlkqkJlYbHZHPwhFhXFIZPIlCp1KiVv9TDBEKIANZkdIrOi8-lC9LrWZFFYgahkOSMAASZkRQJBajge2lIUISJBb14zR4nysovFguFurmZNlEEI8sVKrVBpYWp1-hmIXmwEW+o1LDeJgc1Dgg1yizYigFLAAntqbb7-RGWFHqDH40aeCazejvibUbT7E4gA)

## marimo.ui.dropdown

```python
dropdown(
    options: Sequence[Any] | dict[str, Any],
    value: Any | None = None,
    allow_select_none: bool | None = None,
    searchable: bool = False,
    *,
    label: str = "",
    on_change: Callable[[Any], None] | None = None,
    full_width: bool = False,
)
```

Bases: `UIElement[list[str], Any]`

A dropdown selector.

Examples:

```python
dropdown = mo.ui.dropdown(
    options=["a", "b", "c"], value="a", label="choose one"
)

# With search functionality
dropdown = mo.ui.dropdown(
    options=["a", "b", "c"],
    value="a",
    label="choose one",
    searchable=True,
)
```

```python
dropdown = mo.ui.dropdown(
    options={"one": 1, "two": 2, "three": 3},
    value="one",
    label="pick a number",
)
```

Or from a dataframe series:
```python
dropdown = mo.ui.dropdown.from_series(df["column_name"])
```

| ATTRIBUTE | DESCRIPTION |
| --- | --- |
| `[value](#marimo.ui.dropdown.value)` | The selected value, or None if no selection. **TYPE:** `Any` |
| `[options](#marimo.ui.dropdown.options)` | A dict mapping option name to option value. **TYPE:** `dict` |
| `[selected_key](#marimo.ui.dropdown.selected_key)` | The selected option's key, or None if no selection. **TYPE:** `str` |

| PARAMETER | DESCRIPTION |
| --- | --- |
| `options` | Sequence of options, or dict mapping option name to option value. If the options are not strings, they will be converted to strings when displayed in the dropdown. **TYPE:** `Sequence[Any] \| dict[str, Any]` |
| `value` | Default option name. Defaults to None. **TYPE:** `str` **DEFAULT:** `None` |
| `allow_select_none` | Whether to include special option ("--") for a None value; when None, defaults to True when value is None. Defaults to None. **TYPE:** `bool` **DEFAULT:** `None` |
| `searchable` | Whether to enable search functionality. Defaults to False. If the number of options is greater than 1000, this will be set to True, automatically. **TYPE:** `bool` **DEFAULT:** `False` |
| `label` | Markdown label for the element. Defaults to "". **TYPE:** `str` **DEFAULT:** `''` |
| `on_change` | Optional callback to run when this element's value changes. Defaults to None. **TYPE:** `Callable[[Any], None]` **DEFAULT:** `None` |
| `full_width` | Whether the input should take up the full width of its container. Defaults to False. **TYPE:** `bool` **DEFAULT:** `False` |

### options `instance-attribute`

```python
options = options
```

### selected\_key `property`

```python
selected_key: str | None
```

The selected option's key, or `None` if no selection.

### text `property`

```python
text: str
```

A string of HTML representing this element.

### value `property` `writable`

```python
value: T
```

The element's current value.

### batch

```python
batch(**elements: UIElement[Any, Any]) -> batch
```

Convert an HTML object with templated text into a UI element.

This method lets you create custom UI elements that are represented
by arbitrary HTML.

> **Example**
>
> ```python3
> user_info = mo.md(
>     '''
>     - What's your name?: {name}
>     - When were you born?: {birthday}
>     '''
> ).batch(name=mo.ui.text(), birthday=mo.ui.date())
> ```
> In this example, `user_info` is a UI Element whose output is markdown
> and whose value is a dict with keys `'name'` and '`birthday`'
> (and values equal to the values of their corresponding elements).

| PARAMETER | DESCRIPTION |
| --- | --- |
| `elements` | the UI elements to interpolate into the HTML template. **TYPE:** `UIElement[Any, Any]` **DEFAULT:** `{}` |

### callout

```python
callout(
    kind: Literal[
        "neutral", "danger", "warn", "success", "info"
    ] = "neutral",
) -> Html
```

Create a callout containing this HTML element.

A callout wraps your HTML element in a raised box, emphasizing its
importance. You can style the callout for different situations with the
`kind` argument.

Examples:

```python3
mo.md("Hooray, you did it!").callout(kind="success")
```

```python3
mo.md("It's dangerous to go alone!").callout(kind="warn")
```

### center

```python
center() -> Html
```

Center an item.

> **Example**
>
> ```python3
> mo.md("# Hello, world").center()
> ```

| RETURNS | DESCRIPTION |
| --- | --- |
| `[Html](https://docs.marimo.io/api/html/#marimo.Html)` | An `Html` object. |

### form

```python
form(
    label: str = "",
    *,
    bordered: bool = True,
    loading: bool = False,
    submit_button_label: str = "Submit",
    submit_button_tooltip: str | None = None,
    submit_button_disabled: bool = False,
    clear_on_submit: bool = False,
    show_clear_button: bool = False,
    clear_button_label: str = "Clear",
    clear_button_tooltip: str | None = None,
    validate: Callable[[JSONType | None], str | None]
    | None = None,
    on_change: Callable[[T | None], None] | None = None,
) -> form[S, T]
```

Create a submittable form out of this `UIElement`.

Creates a form that gates submission of a `UIElement`'s value until a submit button is clicked.
The form's value is the value of the underlying element from the last submission.

Examples:

Convert any `UIElement` into a form:
```python
prompt = mo.ui.text_area().form()
```

Combine with `HTML.batch` to create a form made out of multiple `UIElements`:
```python
form = (
    mo.md(
        '''
    **Enter your prompt.**

    {prompt}

    **Choose a random seed.**

    {seed}
    '''
    )
    .batch(
        prompt=mo.ui.text_area(),
        seed=mo.ui.number(),
    )
    .form()
)
```

| PARAMETER | DESCRIPTION |
| --- | --- |
| `label` | A text label for the form. **TYPE:** `str` **DEFAULT:** `''` |
| `bordered` | Whether the form should have a border. **TYPE:** `bool` **DEFAULT:** `True` |
| `loading` | Whether the form should be in a loading state. **TYPE:** `bool` **DEFAULT:** `False` |
| `submit_button_label` | The label of the submit button. **TYPE:** `str` **DEFAULT:** `'Submit'` |
| `submit_button_tooltip` | The tooltip of the submit button. **TYPE:** `str \| None` **DEFAULT:** `None` |
| `submit_button_disabled` | Whether the submit button should be disabled. **TYPE:** `bool` **DEFAULT:** `False` |
| `clear_on_submit` | Whether the form should clear its contents after submitting. **TYPE:** `bool` **DEFAULT:** `False` |
| `show_clear_button` | Whether the form should show a clear button. **TYPE:** `bool` **DEFAULT:** `False` |
| `clear_button_label` | The label of the clear button. **TYPE:** `str` **DEFAULT:** `'Clear'` |
| `clear_button_tooltip` | The tooltip of the clear button. **TYPE:** `str \| None` **DEFAULT:** `None` |
| `validate` | A function that takes the form's value and returns an error message if invalid, or `None` if valid. **TYPE:** `Callable[[JSONType \| None], str \| None] \| None` **DEFAULT:** `None` |
| `on_change` | Optional callback to run when this element's value changes. Defaults to None. **TYPE:** `Callable[[T \| None], None] \| None` **DEFAULT:** `None` |

### from\_args `classmethod`

```python
from_args(
    data: dict[str, int],
    args: InitializationArgs[S, T],
    memo: dict[int, Any] | None = None,
    basis: UIElement[S, T] | None = None,
) -> UIElement[S, T]
```

### from\_series `staticmethod`

```python
from_series(
    series: DataFrameSeries, **kwargs: Any
) -> dropdown
```

Create a dropdown from a dataframe series.

### left

```python
left() -> Html
```

Left-justify.

> **Example**
>
> ```python3
> mo.md("# Hello, world").left()
> ```

| RETURNS | DESCRIPTION |
| --- | --- |
| `[Html](https://docs.marimo.io/api/html/#marimo.Html)` | An `Html` object. |

### right

```python
right() -> Html
```

Right-justify.

> **Example**
>
> ```python3
> mo.md("# Hello, world").right()
> ```

| RETURNS | DESCRIPTION |
| --- | --- |
| `[Html](https://docs.marimo.io/api/html/#marimo.Html)` | An `Html` object. |

### style

```python
style(
    style: dict[str, Any] | None = None, **kwargs: Any
) -> Html
```

Wrap an object in a styled container.

> **Example**
>
> ```python
> mo.md("...").style({"max-height": "300px", "overflow": "auto"})
> mo.md("...").style(max_height="300px", overflow="auto")
> ```

| PARAMETER | DESCRIPTION |
| --- | --- |
| `style` | an optional dict of CSS styles, keyed by property name **TYPE:** `dict[str, Any] \| None` **DEFAULT:** `None` |
| `**kwargs` | CSS styles as keyword arguments **TYPE:** `Any` **DEFAULT:** `{}` |