Update app.py

app.py

@@ -5,45 +5,33 @@ import numpy as np
 import altair as alt
 import pydeck as pdk
 
-
-def create_sessionmaker():
-    a=1
-    
-@st.experimental_singleton
-def get_database_session(_sessionmaker, url):
-     # Create a database connection object that points to the URL.
-     return connection
-
-s1 = get_database_session(create_sessionmaker(), st.session_state.qp)
-# Actually executes the function, since this is the first time it was
-# encountered.
-
-s2 = get_database_session(create_sessionmaker(), st.session_state.qp)
-# Does not execute the function. Instead, returns its previously computed
-# value - even though the _sessionmaker parameter was different
-# in both calls.
-
+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)
-    get_database_session(st.session_state.qp)
 
-options = st.selectbox(
-    "Param", ["cat", "dog", "mouse", "bat", "duck"], key="qp", on_change=update_params
-)
+options = ["cat", "dog", "mouse", "bat", "duck"]
 
 query_params = st.experimental_get_query_params()
 
-# set the initial query param on first run
-# based on the default option in selectbox
-if not query_params:
-    st.experimental_set_query_params(option=st.session_state.qp)
+# 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
 
-# display for debugging purposes
-query_params = st.experimental_get_query_params()
-st.write(query_params)
+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())
 
 
 # SETTING PAGE CONFIG TO WIDE MODE AND ADDING A TITLE AND FAVICON