Refactor player and stack frame calculations in app.py

- Updated the logic for calculating player and stack frame displays to use DataFrame indexing, improving accuracy in the 'Relation to the field' view.
- Implemented subtraction with fill values to handle missing data more effectively, enhancing data integrity in the application.
- Ensured consistent resetting of indices for cleaner DataFrame presentation, improving overall user experience.

app.py

@@ -247,7 +247,10 @@ with tab2:
                 if player_view_var == 'Percentage used':
                     player_frame_display = st.session_state['player_frame']
                 elif player_view_var == 'Relation to the field':
-                    player_frame_display = st.session_state['player_frame'] - st.session_state['field_player_frame']
+                    player_frame = st.session_state['player_frame'].set_index('Player')
+                    field_player_frame = st.session_state['field_player_frame'].set_index('Player')
+                    player_frame_display = player_frame.subtract(field_player_frame, fill_value=0)
+                    player_frame_display = player_frame_display.reset_index(drop=True)
                 st.dataframe(player_frame_display.
                     sort_values(by='Exposure Overall', ascending=False).
                     style.background_gradient(cmap='RdYlGn').
@@ -258,7 +261,10 @@ with tab2:
                 if player_view_var == 'Percentage used':
                     player_frame_display = st.session_state['player_frame']
                 elif player_view_var == 'Relation to the field':
-                    player_frame_display = st.session_state['player_frame'] - st.session_state['field_player_frame']
+                    player_frame = st.session_state['player_frame'].set_index('Player')
+                    field_player_frame = st.session_state['field_player_frame'].set_index('Player')
+                    player_frame_display = player_frame.subtract(field_player_frame, fill_value=0)
+                    player_frame_display = player_frame_display.reset_index(drop=True)
                 st.dataframe(player_frame_display.
                     sort_values(by='Exposure Overall', ascending=False).
                     style.background_gradient(cmap='RdYlGn').
@@ -272,7 +278,10 @@ with tab2:
                 if stack_view_var == 'Percentage used':
                     stack_frame_display = st.session_state['stack_frame']
                 elif stack_view_var == 'Relation to the field':
-                    stack_frame_display = st.session_state['stack_frame'] - st.session_state['field_stack_frame']
+                    stack_frame = st.session_state['stack_frame'].set_index('Stack')
+                    field_stack_frame = st.session_state['field_stack_frame'].set_index('Stack')
+                    stack_frame_display = stack_frame.subtract(field_stack_frame, fill_value=0)
+                    stack_frame_display = stack_frame_display.reset_index(drop=True)
                 st.dataframe(stack_frame_display.
                     sort_values(by='Exposure Overall', ascending=False).
                     style.background_gradient(cmap='RdYlGn').
@@ -283,7 +292,10 @@ with tab2:
                 if stack_view_var == 'Percentage used':
                     stack_frame_display = st.session_state['stack_frame']
                 elif stack_view_var == 'Relation to the field':
-                    stack_frame_display = st.session_state['stack_frame'] - st.session_state['field_stack_frame']
+                    stack_frame = st.session_state['stack_frame'].set_index('Stack')
+                    field_stack_frame = st.session_state['field_stack_frame'].set_index('Stack')
+                    stack_frame_display = stack_frame.subtract(field_stack_frame, fill_value=0)
+                    stack_frame_display = stack_frame_display.reset_index(drop=True)
                 st.dataframe(stack_frame_display.
                     sort_values(by='Exposure Overall', ascending=False).
                     style.background_gradient(cmap='RdYlGn').