Form couldn't show additional input field if checkbox was selected

Hello, Iโ€™ve tried to develop interactive quiz based on Streamlit.
I have list of prepared questions and answers.
My code is:
data is DataFrame as like:

     Question                      Answer           type_of_button   add_other_option
 What is your favourite country?  ['USA','Canada']   checkbox              Yes
 Do you have pets?                ['Yes', 'No']      radiobutton           No
 Do you like travelling?          ['Yes', 'No']      radiobutton           No
 What is your favourite meal?     ['Meat', 'Salad']  checkbox              Yes                            

and the function to show Q&A on the form is:

import streamlit as st

def display_question(index):
    question = data.loc[index, 'Question']
    provided_answers = eval(data.loc[index, 'Answer'])
    button_type = data.loc[index, 'type_of_button']
    add_other_option = data.loc[index, 'add_other_option']
    user_answer_lst = []
    if button_type == 'radiobutton':
        current_answer ="", options=provided_answers, key=f"radio_{index}")
        if add_other_option == 'Yes':
        user_answer_lst = []
        for opt in provided_answers:
            answer_check_box = st.checkbox(opt, key=f"{index}_{opt}")
            if answer_check_box:
                if opt == 'Other':
                    additional_option = st.text_input("Please specify:", key=f"{opt}_{index}")
                    if additional_option:
    # Update the session state with the collected answers
    if len(st.session_state['answers']) <= index:
        st.session_state['answers'][index] = user_answer_lst

to call this function I use streamlit.form:

with st.form(key='my_form'):
    if st.session_state['current_question'] < len(data) - 1:
        if st.form_submit_button('Next'):
            st.session_state['current_question'] += 1
        display_question(st.session_state['current_question'])  # Display the last question again
        if st.form_submit_button("Generate Output"):
            questions = data['Question'].tolist()
            answers = st.session_state['answers']
            qa_pairs = {q: a for q, a in zip(questions, answers)}

Problem is:
if user selects Other than form doesnโ€™t show additional st.text_input where is possible to print answer manually.

How is it possible to fix this issue? Thanks

Hi @sv_evath

It seems the problem may be in the nested widgets that resets the app upon interaction. Please see section number 1 in this blog (10 most common explanations on the Streamlit forum). I would suggest to refactor the code by making use of Session State to store responses and parameter values that are in a nested conditional statement. Also look into defining the Session State at the onset of the app.

Here are some Docs to refer to on Session State: