Update app.py

app.py

@@ -41,11 +41,11 @@ YOUTUBE_URL_3 = "https://www.youtube.com/watch?v=vw-KWfKwvTQ"
 MODEL_NAME  = "gpt-4"
 
 def invoke(openai_api_key, use_rag, prompt):
-    llm = ChatOpenAI(model_name = MODEL_NAME, 
-                     openai_api_key = openai_api_key, 
-                     temperature = 0)
-    if (use_rag):
-        try:
+    try:
+        llm = ChatOpenAI(model_name = MODEL_NAME, 
+                         openai_api_key = openai_api_key, 
+                         temperature = 0)
+        if (use_rag):
             # Document loading
             #docs = []
             # Load PDF
@@ -77,11 +77,11 @@ def invoke(openai_api_key, use_rag, prompt):
                                                     return_source_documents = True)
             result = rag_chain({"query": prompt})
             result = result["result"]
-        except Exception as e:
-            raise gr.Error(e)
-    else:
-        chain = LLMChain(llm = llm, prompt = LLM_CHAIN_PROMPT)
-        result = chain.run({"question": prompt})
+        else:
+            chain = LLMChain(llm = llm, prompt = LLM_CHAIN_PROMPT)
+            result = chain.run({"question": prompt})
+    except Exception as e:
+        raise gr.Error(e)
     return result
 
 description = """<strong>Overview:</strong> Reasoning application that demonstrates a <strong>Large Language Model (LLM)</strong> with