Display a select widget.

Function signature[source]

st.selectbox(label, options, index=0, format_func=special_internal_function, key=None, help=None, on_change=None, args=None, kwargs=None, *, placeholder="Choose an option", disabled=False, label_visibility="visible")

Parameters

label (str)

A short label explaining to the user what this select widget is for. The label can optionally contain Markdown and supports the following elements: Bold, Italics, Strikethroughs, Inline Code, Emojis, and Links.

This also supports:

  • Emoji shortcodes, such as :+1: and :sunglasses:. For a list of all supported codes, see https://share.streamlit.io/streamlit/emoji-shortcodes.
  • LaTeX expressions, by wrapping them in "$" or "$$" (the "$$" must be on their own lines). Supported LaTeX functions are listed at https://katex.org/docs/supported.html.
  • Colored text and background colors for text, using the syntax :color[text to be colored] and :color-background[text to be colored], respectively. color must be replaced with any of the following supported colors: blue, green, orange, red, violet, gray/grey, rainbow. For example, you can use :orange[your text here] or :blue-background[your text here].

Unsupported 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.

For accessibility reasons, you should never set an empty label (label="") but 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. For example, this can be a list, numpy.ndarray, pandas.Series, pandas.DataFrame, or pandas.Index. For pandas.DataFrame, the first column is used. Each label will be cast to str internally by default.

index (int)

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 the labels. It receives the option as an argument and its output will be cast to str.

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. Multiple widgets of the same type may not share the same key.

help (str)

An optional tooltip that gets displayed next to the selectbox.

on_change (callable)

An optional callback invoked when this selectbox'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.

placeholder (str)

A string to display when no options are selected. Defaults to "Choose an option".

disabled (bool)

An optional boolean, which disables the selectbox if set to True. The default is False.

label_visibility ("visible", "hidden", or "collapsed")

The visibility of the label. 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".

Returns

(any)

The selected option or None if no option is selected.

Example

import streamlit as st

option = st.selectbox(
    "How would you like to be contacted?",
    ("Email", "Home phone", "Mobile phone"))

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

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

import streamlit as st

option = st.selectbox(
   "How would you like to be contacted?",
   ("Email", "Home phone", "Mobile phone"),
   index=None,
   placeholder="Select contact method...",
)

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

Select 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". Select widgets can also be disabled with the disabled 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 col1, col2 = st.columns(2) with col1: st.checkbox("Disable selectbox widget", key="disabled") st.radio( "Set selectbox label visibility πŸ‘‰", key="visibility", options=["visible", "hidden", "collapsed"], ) with col2: option = st.selectbox( "How would you like to be contacted?", ("Email", "Home phone", "Mobile phone"), label_visibility=st.session_state.visibility, disabled=st.session_state.disabled, )
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