code: def chuan_hoa_dau_cau_tieng_viet(sentence):
      """
      Chuyển câu tiếng việt về chuẩn gõ dấu kiểu cũ.
      :param sentence:
      :return:
      """
      sentence = sentence.lower()
      words = sentence.split()
      for index, word in enumerate(words):
          cw = re.sub(
              r"(^\p{P}*)([p{L}.]*\p{L}+)(\p{P}*$)", r"\1/\2/\3", word
          ).split("/")
          # print(cw)
          if len(cw) == 3:
              cw[1] = chuan_hoa_dau_tu_tieng_viet(cw[1])
          words[index] = "".join(cw)
      return " ".join(words)
  
file_path: underthesea/examples/text_normalize/tools/nvh.py
imports: import regex
label_desc: Use image node_id 7 for calling a global function with example usage: chuan_hoa_dau_cau_tieng_viet(sentence) and returns: str