Dropdown

Dropdown menu for selecting options

mo.ui.dropdown

Create a dropdown menu for selecting from a list of options.

Signature

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

Parameters

options · Sequence[str] | dict[str, Any] · required

List of options or dictionary mapping labels to values

value · str

Initially selected value

allow_select_none · bool

Allow deselecting to have no selection (defaults to True if value is None)

searchable · bool · default: "False"

Enable search filtering of options

label · str · default: "''"

Markdown label for the dropdown

full_width · bool · default: "False"

Whether dropdown takes full width

Examples

import marimo as mo

# Simple dropdown
dropdown = mo.ui.dropdown(
    options=["Apple", "Banana", "Cherry"],
    value="Apple"
)
dropdown

# Dropdown with value mapping
dropdown = mo.ui.dropdown(
    options={
        "Small": "sm",
        "Medium": "md",
        "Large": "lg"
    },
    label="**Select size:**"
)

mo.md(f"Selected: {dropdown.value}")  # Returns "sm", "md", or "lg"

# Searchable dropdown
countries = mo.ui.dropdown(
    options=["USA", "UK", "Canada", "Australia", "Germany"],
    searchable=True,
    label="Country"
)

For multiple selections, use mo.ui.multiselect() instead.