code: def normalize_LCSH(subject):
      
      # Strip then divide on -- which is a delimiter for LCSH;
      # rejoin after stripping parts.
      subject_parts = subject.strip().split('--')
      joined_subject = ' -- '.join([part.strip() for part in subject_parts])
  
      # Check if there is punctuation at the end of the string,
      # and if not, add a trailing period.
      if re.search(r'[^a-zA-Z0-9]$', joined_subject) is None:
          joined_subject = joined_subject + '.'
  
      return joined_subject
docs: Normalize a LCSH subject heading prior to indexing.