| 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") | |
| 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. Display unsupported elements as literal characters by backslash-escaping them. E.g., "1\. Not an ordered list". 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 or int) | An optional string or integer to use as the unique key for the widget. If this is omitted, a key will be generated for the widget based on its content. No two widgets may have the same key. |
help (str) | An optional tooltip that gets displayed next to the widget label. Streamlit only displays the tooltip when label_visibility="visible". |
on_change (callable) | An optional callback invoked when this radio's value changes. |
args (tuple) | An optional 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 alligned with other widgets. If this is "collapsed", Streamlit displays no label or spacer. |
| Returns | |
(any) | The selected option or None if no option is selected. |
Example
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.")To initialize an empty radio widget, use None as the index value:
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)
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:
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,
)
Featured videos
Check out our video on how to use one of Streamlit's core functions, the radio button! 🔘
In the video below, we'll take it a step further and learn how to combine a button, checkbox and radio button!
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