Update app.py

app.py

@@ -53,6 +53,8 @@ def get_data(lookback_days: float, user_query: str):
     query = f"cat:hep-th AND submittedDate:[{min_date.strftime('%Y%m%d')} TO {max_date.strftime('%Y%m%d')}]"
     loader = ArxivLoader(query=query, load_max_docs=LOAD_MAX_DOCS)
     docs = [process_document(doc) for doc in loader.load()]
+    if len(docs) == 0:
+        return "Found no documents. Consider increasing the value for 'Articles from this many days in the past will be searched through.'."
     db = Chroma.from_documents(docs, embeddings)
     retriever = db.as_retriever()    
     relevant_docs = retriever.get_relevant_documents(user_query)