Update ViHOS.py

ViHOS.py

@@ -57,6 +57,8 @@ class ViHOS(datasets.GeneratorBasedBuilder):
             id_ = data.loc[i, 'id']
             content = data.loc[i, 'Content']
             span_ids = data.loc[i, 'Span ids']
+            if span_ids is None:
+                span_ids = ''
     
             yield id_, {
                 "content": content,