Enhance player filtering in app.py by adding position selection feature

- Introduced a radio button for selecting player positions, allowing users to filter displayed players based on their chosen positions.
- Updated the player frame to include a position column and applied a mask to filter players according to the selected positions, improving data relevance and user experience.

app.py

@@ -209,12 +209,22 @@ with tab2:
         with st.container():
             tab1, tab2, tab3, tab4 = st.tabs(['Player Used Info', 'Stack Used Info', 'Stack Size Info', 'General Info'])
             with tab1:
+                col1, col2 = st.columns(2)
+                with col1:
+                    pos_var = st.radio('All Positions or Select?', ['All', 'Select'])
+                with col2:
+                    if pos_var == 'Select':
+                        pos_list = st.multiselect('Select Positions', ['P', 'C', '1B', '2B', '3B', 'SS', 'OF'])
+                    else:
+                        pos_list = ['P', 'C', '1B', '2B', '3B', 'SS', 'OF']
 
                 if entry_parse_var == 'All':
                     st.session_state['player_frame'] = create_player_exposures(working_df, player_columns)
                     hold_frame = st.session_state['player_frame'].copy()
                     hold_frame['Pos'] = hold_frame['Player'].map(map_dict['pos_map'])
-                    st.session_state['player_frame'].insert(2, 'Pos', hold_frame['Pos'])
+                    st.session_state['player_frame'].insert(1, 'Pos', hold_frame['Pos'])
+                    position_mask = st.session_state['player_frame']['Pos'].apply(lambda x: any(pos in x for pos in pos_list))
+                    st.session_state['player_frame'] = st.session_state['player_frame'][position_mask]
                     st.dataframe(st.session_state['player_frame'].
                         sort_values(by='Exposure Overall', ascending=False).
                         style.background_gradient(cmap='RdYlGn').
@@ -224,7 +234,9 @@ with tab2:
                     st.session_state['player_frame'] = create_player_exposures(working_df, player_columns, entry_names)
                     hold_frame = st.session_state['player_frame'].copy()
                     hold_frame['Pos'] = hold_frame['Player'].map(map_dict['pos_map'])
-                    st.session_state['player_frame'].insert(2, 'Pos', hold_frame['Pos'])
+                    st.session_state['player_frame'].insert(1, 'Pos', hold_frame['Pos'])
+                    position_mask = st.session_state['player_frame']['Pos'].apply(lambda x: any(pos in x for pos in pos_list))
+                    st.session_state['player_frame'] = st.session_state['player_frame'][position_mask]
                     st.dataframe(st.session_state['player_frame'].
                         sort_values(by='Exposure Overall', ascending=False).
                         style.background_gradient(cmap='RdYlGn').