Enhance player selection state management in Handbuilder tab of app.py by initializing and maintaining a session state for selected indices. Implement logic to handle out-of-range selections and update the display based on current selections, improving user experience and selection accuracy.

app.py

@@ -807,6 +807,7 @@ with tab4:
 
     if st.button("Clear Data", key='clear_handbuild'):
         st.session_state.handbuilder_editor_key += 1
+        st.session_state.handbuilder_selected_indices = []
         st.rerun()
 
     # --- TEAM FILTER UI ---
@@ -831,6 +832,16 @@ with tab4:
     else:
         player_select_df = dk_roo[['Player', 'Position', 'Team', 'Salary', 'Median', 'Order', 'Hand', 'Own%']].copy()
 
+    # --- ROW SELECTION STATE ---
+    # Map previous selection to the new filtered DataFrame
+    if 'handbuilder_selected_indices' not in st.session_state:
+        st.session_state.handbuilder_selected_indices = []
+
+    # Remove indices that are out of range (in case the player pool shrinks)
+    st.session_state.handbuilder_selected_indices = [
+        i for i in st.session_state.handbuilder_selected_indices if i < len(player_select_df)
+    ]
+
     col1, col2 = st.columns([1, 2])
     with col2:
         st.subheader("Player Select")
@@ -838,12 +849,16 @@ with tab4:
             player_select_df,
             key=f"handbuilder_editor_{st.session_state.handbuilder_editor_key}",
             on_select="rerun",
-            selection_mode=["multi-row"]
+            selection_mode=["multi-row"],
+            selected_rows=st.session_state.handbuilder_selected_indices
         )
 
+        # Update session state with new selection if changed
+        if event and "rows" in event.selection:
+            st.session_state.handbuilder_selected_indices = event.selection["rows"]
+
     # Get selected rows
-    selected_indices = event.selection["rows"] if event and "rows" in event.selection else []
-    select_players_disp = player_select_df.iloc[selected_indices][['Player', 'Team', 'Salary', 'Median', 'Own%']]
+    select_players_disp = player_select_df.iloc[st.session_state.handbuilder_selected_indices][['Player', 'Team', 'Salary', 'Median', 'Own%']]
 
     with col1:
         st.subheader("Lineup")