Update app.py

app.py

@@ -114,7 +114,10 @@ def query(category, text):
     1. Construct a prompt
     2. Generate a response
     """
-    category = Category[category]
+    try:
+        category = Category[category]
+    except KeyError:
+        return [{"error": f"Invalid category: {category}"}]
     chain = categories.category_modules[category].chain
     formatted_prompt = chain.prompt.format_prompt(
         text=text,