Update chains/arxiv_chains.py

chains/arxiv_chains.py

@@ -15,6 +15,8 @@ from langchain.chains.qa_with_sources.retrieval import RetrievalQAWithSourcesCha
 from langchain.chains.combine_documents.base import BaseCombineDocumentsChain
 from langchain.chains.combine_documents.stuff import StuffDocumentsChain
 
+from langchain_experimental.sql.parser import VectorSQLOutputParser
+
 
 class VectorSQLRetrieveCustomOutputParser(VectorSQLOutputParser):
     """Based on VectorSQLOutputParser