code: def pun_num(self, s):
      for token in s.split():
          if token in string.punctuation:
              if token == ".":
                  s = s
              else:
                  s = s.replace(token, "punc")
          else:
              s = s
      return s
  
imports: from sklearn.base import BaseEstimator, TransformerMixin
  import string
  import re
  from underthesea.pipeline.word_tokenize import tokenize
  from underthesea.utils.vietnamese_features import remove_tone
label_desc: Use image node_id 1 for calling the Tokenize obj's underlying member method code with example usage: obj.pun_num(s) and returns: s