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

# File

[Interactive marimo example](https://marimo.app/?embed=true&mode=edit&show-chrome=false#code/JYWwDg9gTgLgBCAhlUEBQixjgXgc1AOgEEsAKAd2ABMYALHAIhAFNrgBXERgSjTQACmMIQDGLADYS01FgDM4AfUVkeALjRwtcUJFj4UICHEQBnBOm1woLGBygA7QcLGTpshctUarc4BJZFACMOGBgIB1wLQg5gQj8AsgBrYAdqJhCwiN5NbQTA5BZEKKMYuPzk1PTGQsQcqxs7Rzh8xVqAGhb-QMzwp2csVykZeSUyVo6ugODQvs6jdVytUoA3UxhEUSSyAG1W3ojOiZtEAF0+Btt7fqFB8WGPMeOio+6ZrId5iEWrAGI4YiicSmcwcMASCCIWTUKYsUxLaJrDZbXYIqylEDUcaMABCswicDBEKhajgAG99viHIQHIhWKodApKR9CCtEBIOCw4JJTFyAOQAOWM+T5AF9eO00doMVi5IxiCdCeDIdRSRS3rUaXSWAzgEyNSdWezOdyJLy4ILhd0xfVtOcEY1rmggA)

## marimo.ui.file

```python
file(
    filetypes: Sequence[str] | None = None,
    multiple: bool = False,
    kind: Literal["button", "area"] = "button",
    *,
    max_size: int = 100000000,
    label: str = "",
    on_change: Callable[[Sequence[FileUploadResults]], None]
    | None = None,
)
```

Bases: `UIElement[list[tuple[str, str]], Sequence[FileUploadResults]]`

A button or drag-and-drop area to upload a file.

Once a file is uploaded, the UI element's value is a list of namedtuples
(name, contents), where name is the filename and contents is the contents
of the file. Alternatively, use the methods name(index: int = 0) and
contents(index: int = 0) to retrieve the name or contents of the file at a
specified index.

Use the kind argument to switch between a button and a drag-and-drop area.

The maximum file size is 100MB.

Examples:

Uploading a single file:
```python
f = mo.ui.file()
f
```

```python
# In another cell, access the uploaded file's name
f.value[0].name
# or
f.name()

# access the uploaded file's contents
f.value[0].contents
# or
f.contents()
```

Uploading multiple files, accepting only .png and .jpg extensions:
```python
f = mo.ui.file(filetypes=[".png", ".jpg"], multiple=True)
f
```

```python
# In another cell, access an uploaded file's name
f.value[index].name
# or
f.name(index)

# access the uploaded file's contents
f.value[index].contents
# or
f.contents(index)
```

| ATTRIBUTE | DESCRIPTION |
| --- | --- |
| `[value](#marimo.ui.file.value)` | A sequence of FileUploadResults, which have string name and bytes contents fields. **TYPE:** `Sequence[FileUploadResults]` |

| METHOD | DESCRIPTION |
| --- | --- |
| `[name](#marimo.ui.file.name)` | int = 0) -> Optional[str]: Get the name of the uploaded file at index. |
| `[contents](#marimo.ui.file.contents)` | int = 0) -> Optional[bytes]: Get the contents of the uploaded file at index. |

| PARAMETER | DESCRIPTION |
| --- | --- |
| `filetypes` | The file types accepted; for example, filetypes=[".png", ".jpg"]. If None, all files are accepted. In addition to extensions, you may provide "audio/*", "video/*", or "image/\*" to accept any audio, video, or image file. Defaults to None. **TYPE:** `Sequence[str]` **DEFAULT:** `None` |
| `multiple` | If True, allow the user to upload multiple files. Defaults to False. **TYPE:** `bool` **DEFAULT:** `False` |
| `kind` | Type of upload interface. Defaults to "button". **TYPE:** `Literal['button', 'area']` **DEFAULT:** `'button'` |
| `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[[Sequence[FileUploadResults]], None]` **DEFAULT:** `None` |
| `max_size` | The maximum size of the file to upload (in bytes). Defaults to 100MB. **TYPE:** `int` **DEFAULT:** `100000000` |

### 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. |

### contents

```python
contents(index: int = 0) -> bytes | None
```

Get file contents at index.

| PARAMETER | DESCRIPTION |
| --- | --- |
| `index` | Index of the file to get the contents from. Defaults to 0. **TYPE:** `int` **DEFAULT:** `0` |

| RETURNS | DESCRIPTION |
| --- | --- |
| `bytes \| None` | Optional[bytes]: The contents of the file at the specified index, or None if index is out of range. |

### 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]
```

### 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. |

### name

```python
name(index: int = 0) -> str | None
```

Get file name at index.

| PARAMETER | DESCRIPTION |
| --- | --- |
| `index` | Index of the file to get the name from. Defaults to 0. **TYPE:** `int` **DEFAULT:** `0` |

| RETURNS | DESCRIPTION |
| --- | --- |
| `str \| None` | Optional[str]: The name of the file at the specified index, or None if index is out of range. |

### 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:** `{}` |