fixed automatic retry if some sheets are failed to load

app.py

@@ -328,7 +328,6 @@ def get_sheet_data(spreadsheet, gid, sheet_name):
             df = pd.DataFrame(data_rows, columns=clean_headers)
             # Remove completely empty columns
             df = df.loc[:, (df != '').any(axis=0)]
-            print(f"✅ Loaded {len(df)} rows from {sheet_name}")
             return df
         else:
             print(f"⚠️ No data rows found in {sheet_name}")
@@ -685,7 +684,7 @@ data_cache = {
 }
 
 def load_all_data():
-    """Load and cache all data from Google Sheets (including reward points data)"""
+    """Load and cache all data from Google Sheets (auto-retries failed sheets with backoff)"""
     global data_cache
     
     if data_cache["is_loading"]:
@@ -694,20 +693,64 @@ def load_all_data():
                 data_cache["details_info"], data_cache["reward_points_df"])
     
     data_cache["is_loading"] = True
-    print(f"🔄 Loading fresh data from {len(sheet_configs)} Google Sheets + Reward Points sheet...")
+    print(f"🔄 Loading data from {len(sheet_configs)} Google Sheets + Reward Points sheet...")
     start_time = time.time()
     
     try:
-        # Load all sheet data from main spreadsheet
         all_dataframes = []
+        failed_sheets = []
+        max_retries = 5  # Prevent infinite recursion
+        retry_delay = 2   # Start with 2 seconds
+
+        # 1️⃣ First attempt to load each sheet
+        print("📋 Initial loading attempt...")
         for config in sheet_configs:
             df = get_sheet_data(main_spreadsheet, config["gid"], config["name"])
-            if not df.empty:
+            if df.empty:
+                print(f"⚠️ {config['name']} failed to load, will retry...")
+                failed_sheets.append(config)
+            else:
                 df['Source_Sheet'] = config["name"]
                 all_dataframes.append(df)
-                print(f"   📋 {config['name']}: {len(df)} rows")
+                print(f"✅ Loaded {len(df)} rows from {config['name']}")
+
+        # 2️⃣ Retry failed sheets with exponential backoff
+        for attempt in range(1, max_retries + 1):
+            if not failed_sheets:
+                break
+                
+            print(f"🔄 Retry attempt {attempt}/{max_retries} for {len(failed_sheets)} failed sheets...")
+            time.sleep(retry_delay)
+            
+            retry_failed = []
+            for config in failed_sheets:
+                print(f"   🔄 Retrying {config['name']}...")
+                df = get_sheet_data(main_spreadsheet, config["gid"], config["name"])
+                if df.empty:
+                    print(f"   ❌ Still failed: {config['name']}")
+                    retry_failed.append(config)
+                else:
+                    df['Source_Sheet'] = config["name"]
+                    all_dataframes.append(df)
+                    print(f"   ✅ Retry success: {config['name']} ({len(df)} rows)")
+
+            failed_sheets = retry_failed
+            retry_delay *= 2  # Exponential backoff: 2s, 4s, 8s
 
-        # Combine dataframes
+        # 3️⃣ Handle permanently failed sheets
+        if failed_sheets:
+            failed_names = [config['name'] for config in failed_sheets]
+            print(f"⚠️ Warning: {len(failed_sheets)} sheets failed after {max_retries} retries: {', '.join(failed_names)}")
+            
+            # Continue with available data instead of aborting
+            if all_dataframes:
+                print(f"✅ Continuing with {len(all_dataframes)} successfully loaded sheets")
+            else:
+                print("❌ Critical: No sheets loaded successfully!")
+                # Return empty data but don't crash
+                return pd.DataFrame(), None, None, None
+        
+        # 4️⃣ Combine successfully loaded sheets
         if all_dataframes:
             try:
                 combined_df = pd.concat(all_dataframes, ignore_index=True, sort=False)
@@ -746,40 +789,47 @@ def load_all_data():
                 print(f"✅ Alternative approach successful: {len(combined_df)} records combined")
         else:
             combined_df = pd.DataFrame()
-            print("❌ No data found in any sheets")
+            print("⚠️ No sheets loaded successfully")
 
-        # Load studentwise reward points data from separate spreadsheet
+        # 5️⃣ Load supporting data (with error handling)
+        print("📊 Loading supporting data...")
         studentwise_data = get_studentwise_data(studentwise_spreadsheet)
-        
-        # Load details info from main spreadsheet
         details_info = get_details_info(main_spreadsheet)
-        
-        # Load reward points activity data
         reward_points_df = load_reward_points_data()
-        
-        # Update cache
-        data_cache["combined_df"] = combined_df
-        data_cache["studentwise_data"] = studentwise_data
-        data_cache["details_info"] = details_info
-        data_cache["reward_points_df"] = reward_points_df
-        data_cache["last_update"] = datetime.now()
-        
+
+        # 6️⃣ Update cache
+        data_cache.update({
+            "combined_df": combined_df,
+            "studentwise_data": studentwise_data,
+            "details_info": details_info,
+            "reward_points_df": reward_points_df,
+            "last_update": datetime.now(),
+        })
+
         load_time = time.time() - start_time
-        print(f"⏱️ Data loaded and cached in {load_time:.2f} seconds")
-        print(f"📊 Next auto-refresh in {data_cache['cache_duration_hours']} hours")
         
+        if failed_sheets:
+            print(f"⚠️ Partial load completed in {load_time:.2f} seconds")
+            print(f"✅ {len(all_dataframes)}/{len(sheet_configs)} sheets loaded successfully")
+        else:
+            print(f"⏱️ All data successfully loaded in {load_time:.2f} seconds")
+            print("✅ Application ready — all sheets verified")
+
         return combined_df, studentwise_data, details_info, reward_points_df
-        
+
     except Exception as e:
-        print(f"❌ Error loading data: {str(e)}")
-        return (data_cache.get("combined_df", pd.DataFrame()), 
-                data_cache.get("studentwise_data", None),
-                data_cache.get("details_info", None),
-                data_cache.get("reward_points_df", None))
-    
+        print(f"❌ Critical error in load_all_data: {str(e)}")
+        return (
+            data_cache.get("combined_df", pd.DataFrame()),
+            data_cache.get("studentwise_data", None),
+            data_cache.get("details_info", None),
+            data_cache.get("reward_points_df", None),
+        )
+
     finally:
         data_cache["is_loading"] = False
 
+
 def get_cached_data():
     """Get data from cache or refresh if 12 hours have passed"""
     now = datetime.now()
@@ -1275,6 +1325,12 @@ with gr.Blocks(
     gr.Markdown("## 🎓 Student Reward Points Checker")
     gr.Markdown("##### Search for Student Details such as Reward Points, Redemption Dates and Innovative Practice (IP) Details")
     gr.Markdown("##### எல்லா புகழும் இறைவனுக்கே ✝ 🕉 ☪")
+    # gr.Markdown("""
+    # ***Available Features*** :
+    # **🔍 Student Search Tab**,
+    # **📚 IP Details Tab**,
+    # **ℹ️ System Info Tab**
+    # """)
     gr.Markdown("💻 **Mode**: Use Desktop Mode in browser for Good UI and UX")
     gr.Markdown("🕒 **Auto-Updates**: Data automatically refreshes when there is a change in Reward Points Sheet")
     gr.Markdown("📝 **Issue/Feedback Form** : [Issue/Feedback Form](https://docs.google.com/forms/d/e/1FAIpQLScnl0udcN2pUDENHl45HIj5HZbvDuwZ0g2eepBbp8tJYg-NvQ/viewform)")