How to make three select boxes and only select one of the options in the whole three select boxes is allowed?

Using Streamlit
1

Hi.
I want to build three selectboxes in the sidebar.
I want the user to be allowed to choose only one item from the whole three selectboxes.

How can i do that?

2

Hello @AnonC0DEr, Welcome to the Streamlit community.

I have written some code similar to what you’re trying to achieve. I have extracted the following snippet to answer your question:

import streamlit as st
import time

form = st.sidebar.form("form", clear_on_submit=True)
with form:
    form.write("**`Choose a box :`**")
    tick_boxes = form.columns(3)
    col_labels = [col.write(f"`Option {idx + 1}`") for idx, col in enumerate(tick_boxes)]
    values = [
        col.checkbox(f"{idx + 1}", key=f"{idx+1}", value=False)
        for idx, col in enumerate(tick_boxes)
    ]
    form.write("")

submit = form.form_submit_button("Submit")
st.info("**Choose an option using the boxes in the sidebar.**")

if submit:
    list_values = [int(i) for i in values]
    if sum(list_values) == 0:
        st.error("**Choose an option!**")
        time.sleep(1)
        st.experimental_rerun()

    elif sum(list_values) > 1:
        st.error("**You can only tick one box!**")
        time.sleep(1)
        st.experimental_rerun()

    elif sum(list_values) == 1:
        # --->
        # the 'value' variable is the one you then use in if-statements:
        # >>> if value == 1:
        value = list_values.index(1) + 1
        # --->
        st.success(f"**Player choose option << {value} >>.**")

The value variable is the one you then use in if-statements such as:

if value == 1:
   pass

You can find the snippet at this gist.

Cheers.

3

Thanks for your answer.
Dose it work for selectbox method too?
I have a lot of items, So I should use selectbox method.

Again thank you for your answer.

4

Hello @AnonC0DEr, I misunderstood your question actually. I somehow read ‘checkbox’ instead of ‘selectbox’ :man_facepalming:.

Here’s the same code adapted to work with selectboxes:

form = st.sidebar.form("form", clear_on_submit=True)
num_boxes = 3

with form:
    form.write("**`Dropdowns :`**")
    values = [
        st.selectbox(f"Options Set {i+1} :", options[i], index=0, key=f"set_{i}")
        for i in range(num_boxes)
    ]

    # st.write(values, values.count(blank_choice))
    form.write("")

submit = form.form_submit_button("Submit")
st.info("**Choose an option using the dropdowns in the sidebar.**")

if submit:
    if values.count(blank_choice) == num_boxes:
        st.error("**Choose an option!**")

    elif values.count(blank_choice) < (num_boxes - 1):
        st.error("**You can only tick one box!**")

    elif values.count(blank_choice) == (num_boxes - 1):
        # the 'final_choice' variable is the one you then use in subsequent code:
        final_choice = [i for i in values if i != blank_choice][-1]
        st.success(f"**Player choose option << {final_choice} >>.**")

image
image1329×806 19.5 KB

You can find the full code at this gist .

Cheers.

5

Thanks, It works very well now.
Cheers.

6

Ah. Nice. You could mark that as an answer then. Makes it easier for others locate. :v: