update session state

app.py

@@ -123,11 +123,23 @@ def single_main(uploaded_file):
 def main():
     add_app_description()
 
+    # Initialize session state for mode if it doesn't exist
     if "mode" not in st.session_state:
         st.session_state["mode"] = "multi"
-
-    selected_mode = st.sidebar.selectbox("Select Mode", ["Multi", "Compare", "Weekly", "Multi-Env Compare"])
-
+    
+    # Initialize session state for the selectbox widget
+    if "selected_mode" not in st.session_state:
+        st.session_state["selected_mode"] = "Multi"
+   
+    # Use the session state for the default value of the selectbox
+    selected_mode = st.sidebar.selectbox(
+        "Select Mode", 
+        ["Multi", "Compare", "Weekly", "Multi-Env Compare"],
+        index=["Multi", "Compare", "Weekly", "Multi-Env Compare"].index(st.session_state["selected_mode"])
+    )
+    
+    # Update the session state with the new selection
+    st.session_state["selected_mode"] = selected_mode
     st.session_state["mode"] = selected_mode.lower()
 
     mode_display = f'## Current mode: {st.session_state["mode"].title()} mode'