have trouble in running reader.py about sa-sent HOT 3 CLOSED

                try:
                    target_start = sent_tokens.index(target_tokens[0])
                    target_end = sent_tokens[max(0, target_start - 1):].index(target_tokens[-1])  + max(0, target_start - 1)
                except:
                    # error
                    # pdb.set_trace()
                    target_start = 0
                    target_end = 1
                    print u'error'

                if target_start < 0 or target_end < 0:
                    target_start = 0
                    target_end = 1
                    print u'error'