How can I switch between two buttons and change their session state?

Using Streamlit
1

Hi all,

I want to make two buttons that when a user clicks one button (A) then a question (a) is displayed; when the user clicks the other button (B) then another question (b) is displayed and the previous question (a) disappears.

Code is below

if "AAA" not in st.session_state:

    st.session_state.AAA = False

if "BBB" not in st.session_state:

    st.session_state.BBB = False

A = st.button("A")

B = st.button("B")

if A or st.session_state.AAA:

    st.session_state.AAA = True    

    st.session_state.BBB = False

    st.radio('a',('a','a','a'))

if B or st.session_state.BBB:

    st.session_state.BBB = True

    st.session_state.AAA = False

    st.radio('b', ('b','b'))

My code works when I switch from session state AAA to BBB, but not the reverse way.
For more details, when question a is displayed, I clicked button B and question b appears but question a is still there.

Thank you!

1 Like
2

Hi Anhhaokudo,
Welcome to Streamlit :smiley:

My solution is a bit of a lazy one but it works for me:

import streamlit as st

if "current" not in st.session_state:

    st.session_state.current = None

if "AAA" not in st.session_state:

    st.session_state.AAA = False

if "BBB" not in st.session_state:

    st.session_state.BBB = False

A = st.button("A")

B = st.button("B")

if A:

    st.session_state.current = "A"

if B:

    st.session_state.current = "B"

if st.session_state.current != None:

    if st.session_state.current == "A":

        st.session_state.AAA = True    

        st.session_state.BBB = False

        st.radio('a',('a','a','a'))

    else:

        st.session_state.BBB = True

        st.session_state.AAA = False

        st.radio('b', ('b','b'))

I use this in my own apps as well but with the dispatch pattern to look up what the current clicked button is and call the according function/Streamlit page widgets that I need.
Not sure if there’s a better way but this works for me :stuck_out_tongue:

Have an awesome day!

2 Likes
3

You are a wizard!
It works for me!!
Thank you so much and have a great weekend.

1 Like
4

haha no problem at all, Streamlit sometimes requires a little bit of magic :sparkles:

Just to expand on your idea a bit more, if you want to have a load of buttons and show something different for each button you can do what I did for my app.

  • Define a function for each “page with widgets” that you want
  • Add a reference to the function in a dictionary
import streamlit as st

def button_one():
    st.radio('a',('a','a','a'))

def button_two():
    st.radio('b',('b','b'))

pages = {
    0 : button_one,
    1 : button_two,
}

if "current" not in st.session_state:

    st.session_state.current = None

# Now you can set the button click to a number and call the linked function
if st.button("A"):
    st.session_state.current = 0
if st.button("B"):
    st.session_state.current = 1

if st.session_state.current != None:
    pages[st.session_state.current]()

There’s probably an even better way to handle this but this is what I’m using :stuck_out_tongue:

Have a great weekend as well!

2 Likes