Added gpt-4 support

app.py

@@ -131,12 +131,12 @@ def get_response(query, chat_history, CRqa):
     return result['answer'], result['source_documents']
 
 
-def setup_em_llm(OPENAI_API_KEY, temperature):
+def setup_em_llm(OPENAI_API_KEY, temperature, r_llm):
     # Set up OpenAI embeddings
     embeddings = OpenAIEmbeddings(openai_api_key=OPENAI_API_KEY)
-    # Use Open AI LLM with gpt-3.5-turbo.
+    # Use Open AI LLM with gpt-3.5-turbo or gpt-4.
     # Set the temperature to be 0 if you do not want it to make up things
-    llm = ChatOpenAI(temperature=temperature, model_name="gpt-3.5-turbo", streaming=True,
+    llm = ChatOpenAI(temperature=temperature, model_name=r_llm, streaming=True,
                      openai_api_key=OPENAI_API_KEY)
     return embeddings, llm
 
@@ -168,6 +168,7 @@ def main(pinecone_index_name, chroma_collection_name, persist_directory, docsear
         r_pinecone = st.radio('Use Pinecone?', ('Yes', 'No'))
         r_ingest = st.radio(
             'Ingest file(s)?', ('Yes', 'No'))
+        r_llm = st.multiselect('LLM:',['gpt-3.5-turbo','gpt-4'],'gpt-3.5-turbo')
     with col2:
         OPENAI_API_KEY = st.text_input(
             "OpenAI API key:", type="password")
@@ -175,7 +176,7 @@ def main(pinecone_index_name, chroma_collection_name, persist_directory, docsear
         k_sources = st.slider('# source(s) to print out', 0, 20, 2)
     with col3:
         if OPENAI_API_KEY:
-            embeddings, llm = setup_em_llm(OPENAI_API_KEY, temperature)
+            embeddings, llm = setup_em_llm(OPENAI_API_KEY, temperature, r_llm)
             if r_pinecone.lower() == 'yes':
                 use_pinecone = True
                 PINECONE_API_KEY = st.text_input(