Update app.py

app.py

@@ -40,6 +40,7 @@ CLASS_OUTPUT_FILE = "data/class_output.csv"
 ALLOWED_EXTENSIONS = {'csv', 'xlsx'}
 
 app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
+app.config['DATA_FOLDER'] = DATA_FOLDER
 
 # Ensure the upload folder exists
 os.makedirs(app.config['UPLOAD_FOLDER'], exist_ok=True)