Setting and getting Streamlit query params

query-params.py

import streamlit as st

# callback to update query param on selectbox change
def update_params():
    st.experimental_set_query_params(option=st.session_state.qp)

options = ["cat", "dog", "mouse", "bat", "duck"]

query_params = st.experimental_get_query_params()

# set selectbox value based on query param, or provide a default
ix = 0
if query_params:
    try:
        ix = options.index(query_params['option'][0])
    except ValueError:
        pass

selected_option = st.radio(
    "Param", options, index=ix, key="qp", on_change=update_params
)

# set query param based on selection
st.experimental_set_query_params(option=selected_option)

# display for debugging purposes
st.write('---', st.experimental_get_query_params())