st.radio

Display a radio button widget.

Function signature[source]
st.radio(label, options, index=0, format_func=special_internal_function, key=None, help=None, on_change=None, args=None, kwargs=None, *, disabled=False, horizontal=False, captions=None, label_visibility="visible", width="content", bind=None)
Parameters
label (str)	A short label explaining to the user what this radio group is for. The label can optionally contain GitHub-flavored Markdown of the following types: Bold, Italics, Strikethroughs, Inline Code, Links, and Images. Images display like icons, with a max height equal to the font height. Unsupported Markdown elements are unwrapped so only their children (text contents) render. Common block-level Markdown (headings, lists, blockquotes) is automatically escaped and displays as literal text in labels. See the `body` parameter of `st.markdown` for additional, supported Markdown directives. For accessibility reasons, you should never set an empty label, but you can hide it with `label_visibility` if needed. In the future, we may disallow empty labels by raising an exception.
options (Iterable)	Labels for the select options in an `Iterable`. This can be a `list`, `set`, or anything supported by `st.dataframe`. If `options` is dataframe-like, the first column will be used. Each label will be cast to `str` internally by default. Labels can include markdown as described in the `label` parameter and will be cast to str internally by default.
index (int or None)	The index of the preselected option on first render. If `None`, will initialize empty and return `None` until the user selects an option. Defaults to 0 (the first option).
format_func (function)	Function to modify the display of radio options. It receives the raw option as an argument and should output the label to be shown for that option. This has no impact on the return value of the radio.
key (str, int, or None)	An optional string or integer to use as the unique key for the widget. If this is `None` (default), a key will be generated for the widget based on the values of the other parameters. No two widgets may have the same key. Assigning a key stabilizes the widget's identity and preserves its state across reruns even when other parameters change. A key lets you read or update the widget's value via `st.session_state[key]`. For more details, see Widget behavior. Additionally, if `key` is provided, it will be used as a CSS class name prefixed with `st-key-`.
help (str or None)	A tooltip that gets displayed next to the widget label. Streamlit only displays the tooltip when `label_visibility="visible"`. If this is `None` (default), no tooltip is displayed. The tooltip can optionally contain GitHub-flavored Markdown, including the Markdown directives described in the `body` parameter of `st.markdown`.
on_change (callable)	An optional callback invoked when this radio's value changes.
args (list or tuple)	An optional list or tuple of args to pass to the callback.
kwargs (dict)	An optional dict of kwargs to pass to the callback.
disabled (bool)	An optional boolean that disables the radio button if set to `True`. The default is `False`.
horizontal (bool)	An optional boolean, which orients the radio group horizontally. The default is false (vertical buttons).
captions (iterable of str or None)	A list of captions to show below each radio button. If None (default), no captions are shown.
label_visibility ("visible", "hidden", or "collapsed")	The visibility of the label. The default is `"visible"`. If this is `"hidden"`, Streamlit displays an empty spacer instead of the label, which can help keep the widget aligned with other widgets. If this is `"collapsed"`, Streamlit displays no label or spacer.
width ("content", "stretch", or int)	The width of the radio button widget. This can be one of the following: `"content"` (default): The width of the widget matches the width of its content, but doesn't exceed the width of the parent container. `"stretch"`: The width of the widget matches the width of the parent container. An integer specifying the width in pixels: The widget has a fixed width. If the specified width is greater than the width of the parent container, the width of the widget matches the width of the parent container.
bind ("query-params" or None)	Binding mode for syncing the widget's value with a URL query parameter. If this is `None` (default), the widget's value is not synced to the URL. When this is set to `"query-params"`, changes to the widget update the URL, and the widget can be initialized or updated through a query parameter in the URL. This requires `key` to be set. The key is used as the query parameter name. When the widget's value equals its default, the query parameter is removed from the URL to keep it clean. A bound query parameter can't be set or deleted through `st.query_params`; it can only be programmatically changed through `st.session_state`. Invalid query parameter values are ignored and removed from the URL. If `index` is `None`, an empty query parameter (e.g., `?my_key=`) clears the widget.
Returns
(any)	The selected option or `None` if no option is selected. This is a copy of the selected option, not the original.

Example

Python

import streamlit as st

genre = st.radio(
    "What's your favorite movie genre",
    [":rainbow[Comedy]", "***Drama***", "Documentary :movie_camera:"],
    captions=[
        "Laugh out loud.",
        "Get the popcorn.",
        "Never stop learning.",
    ],
)

if genre == ":rainbow[Comedy]":
    st.write("You selected comedy.")
else:
    st.write("You didn't select comedy.")

Built with Streamlit 🎈

Fullscreen open_in_new

To initialize an empty radio widget, use None as the index value:

Python

import streamlit as st

genre = st.radio(
    "What's your favorite movie genre",
    [":rainbow[Comedy]", "***Drama***", "Documentary :movie_camera:"],
    index=None,
)

st.write("You selected:", genre)

Built with Streamlit 🎈

Fullscreen open_in_new

Widgets can customize how to hide their labels with the label_visibility parameter. If "hidden", the label doesn’t show but there is still empty space for it above the widget (equivalent to label=""). If "collapsed", both the label and the space are removed. Default is "visible". Radio buttons can also be disabled with the disabled parameter, and oriented horizontally with the horizontal parameter:

Python

import streamlit as st

# Store the initial value of widgets in session state
if "visibility" not in st.session_state:
    st.session_state.visibility = "visible"
    st.session_state.disabled = False
    st.session_state.horizontal = False

col1, col2 = st.columns(2)

with col1:
    st.checkbox("Disable radio widget", key="disabled")
    st.checkbox("Orient radio options horizontally", key="horizontal")

with col2:
    st.radio(
        "Set label visibility 👇",
        ["visible", "hidden", "collapsed"],
        key="visibility",
        label_visibility=st.session_state.visibility,
        disabled=st.session_state.disabled,
        horizontal=st.session_state.horizontal,
    )