Update app.py

app.py

@@ -117,6 +117,13 @@ def preview_dataset(uploaded_file, text_column, label_column):
         # Get the file path from the uploaded file
         file_path = uploaded_file.name if hasattr(uploaded_file, 'name') else uploaded_file
         
+        # Check if file exists and is CSV
+        if not os.path.exists(file_path):
+            return "❌ File not found. Please try uploading again."
+        
+        if not file_path.lower().endswith('.csv'):
+            return "❌ Please upload a CSV file (.csv extension required)."
+        
         df = pd.read_csv(file_path)
         
         preview_info = []
@@ -672,7 +679,7 @@ with gr.Blocks(title="BERT Complaint Classifier", theme=gr.themes.Soft()) as app
         with gr.Column(variant="panel"):
             gr.Markdown("### 🛠️ Training Configuration")
             with gr.Row():
-                uploaded_file = gr.File(label="Upload Training CSV File", type="filepath", file_types=["csv"])
+                uploaded_file = gr.File(label="Upload Training CSV File", type="filepath", file_types=[".csv"])
                 preview_btn = gr.Button("Preview Dataset")
                 preview_output = gr.Markdown("Dataset info will appear here")
             
@@ -739,7 +746,7 @@ with gr.Blocks(title="BERT Complaint Classifier", theme=gr.themes.Soft()) as app
                 
                 gr.Markdown("---")
                 
-                csv_file_input = gr.File(label="Upload CSV File", type="filepath", file_types=["csv"])
+                csv_file_input = gr.File(label="Upload CSV File", type="filepath", file_types=[".csv"])
                 csv_predict_btn = gr.Button("🔮 Predict All", variant="primary")
                 
             csv_prediction_output = gr.Markdown("CSV prediction results will appear here")