Update app.py

app.py

@@ -57,6 +57,9 @@ def main():
     st.title("Player Cards and Monsters")
     st.write("🃏 Select a player card to reveal a monster and battle it! 🐉")
 
+    if "players" not in st.session_state:
+        st.session_state.players = {}
+            
     st.sidebar.title("🃏 Select a Player Card")
     selected_player = st.sidebar.radio("Select a player:", list(PLAYERS.keys()))
     display_player_card(selected_player, PLAYERS[selected_player])