Add pagination functionality to data tables in Streamlit app

- Implemented a new pagination system for displaying data frames in both pitcher and hitter tabs, enhancing user navigation through large datasets.
- Introduced buttons for navigating between pages, improving the overall user experience.
- Adjusted loading spinner duration for league baseline data to optimize perceived performance during data retrieval.

src/streamlit_app.py

@@ -53,6 +53,43 @@ st.markdown("""
     }
 </style>""", unsafe_allow_html=True)
 
+def paginate_dataframe(df, page_size):
+    total_rows = len(df)
+    total_pages = (total_rows + page_size -1) // page_size
+
+    if 'current_page' not in st.session_state:
+        st.session_state['current_page'] = 0
+    
+    start_idx = st.session_state['current_page'] * page_size
+    end_idx = start_idx + page_size
+
+    current_page_data = df.iloc[start_idx:end_idx]
+
+    return current_page_data, total_pages, total_rows
+
+def display_paginated_table(df, page_size):
+    current_page_data, total_pages, total_rows = paginate_dataframe(df, page_size)
+
+    st.dataframe(current_page_data.style.background_gradient(axis=0).background_gradient(cmap='RdYlGn_r').format(precision=2), height = 500, use_container_width = True, hide_index = True)
+
+    col1, col2, col3, col4 = st.columns(1, 2, 2, 1)
+    with col1:
+        if st.button('⏮️ First', disabled=st.session_state.current_page == 0):
+            st.session_state.current_page = 0
+            st.rerun()
+    with col2:
+        if st.button('⬅️ Previous', disabled=st.session_state.current_page == 0):
+            st.session_state.current_page -= 1
+            st.rerun()
+    with col3:
+        if st.button('Next ➡️', disabled=st.session_state.current_page >= total_pages - 1):
+            st.session_state.current_page += 1
+            st.rerun()
+    with col4:
+        if st.button('Last ⏭️', disabled=st.session_state.current_page >= total_pages - 1):
+            st.session_state.current_page = total_pages - 1
+            st.rerun()
+
 @st.cache_resource(ttl = 61)
 def init_baselines():
 
@@ -178,16 +215,8 @@ with pitcher_tab:
     if table_var_sp in (['League Aggregate Baselines', 'League Short Term Baselines', 'League Long Term Baselines']):
 
         with st.spinner("Full league baselines can take some time to load"):
-            time.sleep(7)
-        with sp_disp_container:
-            st.dataframe(st.session_state['sp_disp_frame'].style.background_gradient(axis=0).background_gradient(cmap='RdYlGn_r').format(precision=2), height = 500, use_container_width = True, hide_index = True)
-            col1, col2, col3, col4 = st.columns(4)
-            with col1:
-                if st.button('Previous'):
-                    st.session_state['sp_disp_frame'] = st.session_state['sp_disp_frame'].iloc[:page_var]
-            with col4:
-                if st.button('Next'):
-                    st.session_state['sp_disp_frame'] = st.session_state['sp_disp_frame'].iloc[page_var:]
+            time.sleep(5)
+        display_paginated_table(st.session_state['sp_disp_frame'], 50)
     else:
         with sp_disp_container:
             st.dataframe(st.session_state['sp_disp_frame'].style.background_gradient(axis=0).background_gradient(cmap='RdYlGn_r').format(precision=2), height = 500, use_container_width = True, hide_index = True)
@@ -267,7 +296,9 @@ with hitter_tab:
         if table_var_hitter in (['League Aggregate Baselines', 'League Short Term Baselines', 'League Long Term Baselines']):
             with st.spinner("Full league baselines can take some time to load"):
                 time.sleep(7)
-        st.dataframe(st.session_state['hitter_disp_frame'].style.background_gradient(axis=0).background_gradient(cmap='RdYlGn').format(precision=2), height = 750, use_container_width = True, hide_index = True)
+            display_paginated_table(st.session_state['hitter_disp_frame'], 50)
+        else:
+            st.dataframe(st.session_state['hitter_disp_frame'].style.background_gradient(axis=0).background_gradient(cmap='RdYlGn').format(precision=2), height = 750, use_container_width = True, hide_index = True)
 
 with team_tab:
     with st.container(border = True):