Implement session state initialization and enhance player selection process in Streamlit app

src/streamlit_app.py

@@ -8,6 +8,16 @@ print(f"Streamlit version: {st.__version__}")
 
 st.set_page_config(layout="wide")
 
+@st.cache_data
+def initialize_session_state():
+    """Initialize session state variables"""
+    if 'handbuilder_lineup' not in st.session_state:
+        st.session_state['handbuilder_lineup'] = pd.DataFrame(columns=['Player', 'Position', 'Team', 'Salary', 'Median', '2x%', 'Own', 'Slot'])
+    if 'handbuilder_select_key' not in st.session_state:
+        st.session_state['handbuilder_select_key'] = 0
+    if 'current_tab' not in st.session_state:
+        st.session_state['current_tab'] = "Handbuilder"
+
 @st.cache_resource
 def init_conn():
         uri = st.secrets['mongo_uri']
@@ -305,6 +315,8 @@ def convert_hb_df(array, column_names):
     array = pd.DataFrame(array, columns=column_names)
     return array.to_csv().encode('utf-8')
 
+initialize_session_state()
+
 col1, col2 = st.columns([1, 9])
 with col1:
     if st.button("Load/Reset Data", key='reset'):
@@ -326,7 +338,12 @@ player_stats, dk_stacks_raw, fd_stacks_raw, dk_roo_raw, fd_roo_raw, dk_sd_roo_ra
 
 t_stamp = f"Last Update: " + str(dk_roo_raw['timestamp'][0]) + f" CST"
 
-tab1, tab2, tab3, tab4 = st.tabs(["Stacks ROO", "Player ROO", "Optimals", "Handbuilder"])
+tab_names = ["Stacks ROO", "Player ROO", "Optimals", "Handbuilder"]
+
+if 'current_tab' not in st.session_state:
+    st.session_state['current_tab'] = "Handbuilder"
+
+tab1, tab2, tab3, tab4 = st.tabs(tab_names)
 
 with tab1:
     with st.expander("Info and Filters"):
@@ -1111,43 +1128,71 @@ with tab4:
     col1, col2 = st.columns([1, 2])
     with col2:
         st.subheader("Player Select")
-        event = st.dataframe(
+        
+        # Use a button-based approach for better performance
+        selected_rows = st.dataframe(
             player_select_df.style.background_gradient(axis=0).background_gradient(cmap='RdYlGn').background_gradient(cmap='RdYlGn_r', subset=['Salary', 'Own']).format(precision=2),
-            on_select="rerun",
             selection_mode=["single-row"],
             key=f"handbuilder_select_{st.session_state['handbuilder_select_key']}",
             height=500,
             hide_index=True
         )
-        # If a row is selected, add that player to the lineup and reset selection
-        if event and "rows" in event.selection and len(event.selection["rows"]) > 0:
-            idx = event.selection["rows"][0]
+        
+        # Add a button to confirm selection
+        if selected_rows and "rows" in selected_rows.selection and len(selected_rows.selection["rows"]) > 0:
+            idx = selected_rows.selection["rows"][0]
             player_row = player_select_df.iloc[[idx]]
-            eligible_positions = re.split(r'[/, ]+', player_row['Position'].iloc[0])
-            # Find the first eligible slot that is not full
-            slot_to_fill = None
-
-            for slot in ['QB', 'RB', 'WR', 'TE', 'UTIL', 'DST']:
-                if slot_counts.get(slot, 0) < position_limits.get(slot, 0):
-                    if slot == 'UTIL':
-                        if 'DST' not in eligible_positions and 'QB' not in eligible_positions:
+            
+            # Show selected player info
+            st.info(f"Selected: {player_row['Player'].iloc[0]} ({player_row['Position'].iloc[0]} - {player_row['Team'].iloc[0]})")
+            
+            # Add button to confirm selection
+            if st.button(f"Add {player_row['Player'].iloc[0]} to Lineup", key=f"add_player_{st.session_state['handbuilder_select_key']}"):
+                eligible_positions = re.split(r'[/, ]+', player_row['Position'].iloc[0])
+                slot_to_fill = None
+                
+                # Count current positions
+                current_lineup = st.session_state['handbuilder_lineup']
+                slot_counts = current_lineup['Slot'].value_counts() if not current_lineup.empty else {}
+                
+                for slot in ['QB', 'RB', 'WR', 'TE', 'UTIL', 'DST']:
+                    if slot_counts.get(slot, 0) < position_limits.get(slot, 0):
+                        if slot == 'UTIL':
+                            if 'DST' not in eligible_positions and 'QB' not in eligible_positions:
+                                slot_to_fill = slot
+                                break
+                        elif slot in eligible_positions:
                             slot_to_fill = slot
                             break
-                    elif slot in eligible_positions:
-                        slot_to_fill = slot
-                        break
-
-            if slot_to_fill is not None:
-                # Avoid duplicates
-                if not player_row['Player'].iloc[0] in st.session_state['handbuilder_lineup']['Player'].values:
-                    # Add the slot info
-                    player_row = player_row.assign(Slot=slot_to_fill)
-                    st.session_state['handbuilder_lineup'] = pd.concat(
-                        [st.session_state['handbuilder_lineup'], player_row[['Player', 'Position', 'Team', 'Salary', 'Median', '2x%', 'Own', 'Slot']]],
-                        ignore_index=True
-                    )
-                st.session_state['handbuilder_select_key'] += 1
-                st.rerun()
+                
+                if slot_to_fill is not None:
+                    # Avoid duplicates
+                    if not player_row['Player'].iloc[0] in current_lineup['Player'].values:
+                        # Add the slot info
+                        new_player = pd.DataFrame([{
+                            'Player': player_row['Player'].iloc[0],
+                            'Position': player_row['Position'].iloc[0],
+                            'Team': player_row['Team'].iloc[0],
+                            'Salary': player_row['Salary'].iloc[0],
+                            'Median': player_row['Median'].iloc[0],
+                            '2x%': player_row['2x%'].iloc[0],
+                            'Own': player_row['Own'].iloc[0],
+                            'Slot': slot_to_fill
+                        }])
+                        
+                        st.session_state['handbuilder_lineup'] = pd.concat(
+                            [st.session_state['handbuilder_lineup'], new_player],
+                            ignore_index=True
+                        )
+                        
+                        # Clear the selection and increment key
+                        st.session_state['handbuilder_select_key'] += 1
+                        st.success(f"✅ Added {player_row['Player'].iloc[0]} to {slot_to_fill} slot!")
+                        st.rerun()
+                    else:
+                        st.error(f"❌ {player_row['Player'].iloc[0]} is already in the lineup!")
+                else:
+                    st.error(f"❌ No available slots for {player_row['Player'].iloc[0]}!")
 
 
     with col1: