fix

app.py

@@ -91,7 +91,7 @@ def render_table(forms, lemmas, upos, xpos, feats, metadata, edges, edge_labels)
         ["<b>upos</b>          "] + upos,
         ["<b>xpos</b>          "] + xpos,
         ["<b>feats</b>          "] + feats[0],
-        *([""] + row for row in feats[1:])
+        *([""] + list(row) for row in feats[1:])
     ]
 
     table = prettytable.PrettyTable()