Update app.py

app.py

@@ -62,8 +62,8 @@ def get_documents(category: str, min_date: datetime, max_date: datetime):
     docs = [Document(
         page_content=doc.summary,
         metadata={
-            "authors": doc.authors,
-            "categories": doc.categories,
+            "authors": ", ".join(map(str, doc.authors)),
+            "categories": ", ".join(map(str, doc.categories)),
             "id": doc.get_short_id(),
             "title": doc.title,
         }