Update app.py

app.py

@@ -26,7 +26,7 @@ def fetch_answers(question, clincal_note ):
     for query, passage in top_5_query_paragraph_list:
      passage_sentences = sentence_segmenter.segment(passage)
      answer = qa_model(question = query, context = passage)['answer']
-     evidence_sentence = None
+     evidence_sentence = ""
      for i in range(len(passage_sentences)):
          if answer.startswith('.') or answer.startswith(':'):
              answer = answer[1:].strip()