old_contents: import re
  
  
  class Verse:
      def __init__(self, verses):
          if isinstance(verses, str):
              verses = [verses]
          self._verses = verses
          self._pre_processed = False
  
      def emblem_cut(self, lengths=(2, 3)):
          self._pre_process()
          result = []
          for length in lengths:
              for verse in self._verses:
                  for i in range(len(verse) - (length - 1)):
                      result.append(verse[i:i + length])
          return result
  
      def _pre_process(self):
          if not self._pre_processed:
              self._trim_comment()._punctuation_cut()
              self._pre_processed = True
  
      def _trim_comment(self):
          re_comment = re.compile(r'\(.+?\)')
          result = []
          for verse in self._verses:
              result.append(re_comment.sub('', verse))
          self._verses = result
          return self
  
      def _punctuation_cut(self):
          re_punctuation_list = re.compile(
              r'\n+|,|!|:|;|\(|\)|，|。|？|！|…|：|；|、|‘|’|“|”|（|）|《|》')
          result = []
          for verse in self._verses:
              list_split = re_punctuation_list.split(verse)
              result.extend(list(filter(None, list_split)))
          self._verses = result
          return self
  
new_contents: import re
  
  
  class Verse:
      def __init__(self, verses):
          if isinstance(verses, str):
              verses = [verses]
          self._verses = verses
          self._pre_processed = False
  
      def emblem_cut(self, lengths=(2, 3)):
          self._pre_process()
          result = []
          for length in lengths:
              for verse in self._verses:
                  for i in range(len(verse) - (length - 1)):
                      result.append(verse[i:i + length])
          return result
  
      def _pre_process(self):
          if not self._pre_processed:
              self._trim_comment()._punctuation_cut()
              self._pre_processed = True
  
      def _trim_comment(self):
          re_comment = re.compile(r'\(.+?\)')
          result = []
          for verse in self._verses:
              result.append(re_comment.sub('', verse))
          self._verses = result
          return self
  
      def _punctuation_cut(self):
          re_punctuation_list = re.compile(
              r'\s+|,|!|:|;|\(|\)|，|。|？|！|…|：|；|、|‘|’|“|”|（|）|《|》')
          result = []
          for verse in self._verses:
              list_split = re_punctuation_list.split(verse)
              result.extend(list(filter(None, list_split)))
          self._verses = result
          return self
  
subject: trim duplicated space.