Update app.py

app.py

@@ -20,17 +20,14 @@ from langchain.document_loaders import PyPDFLoader, TextLoader
 from langchain.embeddings import OpenAIEmbeddings
 from langchain.prompts import PromptTemplate, ChatPromptTemplate
 from langchain.text_splitter import RecursiveCharacterTextSplitter
-
 from langchain.vectorstores import MongoDBAtlasVectorSearch, Weaviate
-
 from langchain_core.messages import HumanMessage, SystemMessage
 from langchain_core.output_parsers import StrOutputParser
 from langchain_core.runnables import RunnablePassthrough
 from langchain_openai import ChatOpenAI
-
 # langchain_community imports
-from langchain.embeddings import HuggingFaceEmbeddings
-from langchain.llms import HuggingFacePipeline
+from langchain_community.embeddings import HuggingFaceEmbeddings
+from langchain_community.llms import HuggingFacePipeline
 
 
 # Retrieve environment variables.