Update app.py

app.py

@@ -4,7 +4,7 @@ import gradio as gr
 from langchain_openai import ChatOpenAI
 from langchain.embeddings import HuggingFaceEmbeddings
 from langchain_chroma import Chroma
-from langchain.prompts import ChatPromptTemplate, HumanMessagePromptTemplate
+from langchain.prompts import PromptTemplate, ChatPromptTemplate, HumanMessagePromptTemplate
 from langchain.chains import LLMChain
 
 # Unzip vector DB if not already extracted