Update app.py

app.py

@@ -24,6 +24,7 @@ from langchain_community.document_loaders import PyPDFDirectoryLoader
 # Under the hood, by default this uses the UnstructuredLoader.
 from langchain_community.document_loaders import DirectoryLoader
 from langchain_community.document_loaders import TextLoader
+import chardet
 
 from langchain_community.vectorstores import FAISS
 # from langchain.vectorstores import Chroma