def _word_tokenizer_re(self):
        """Compiles and returns a regular expression for word tokenization"""
        try:
            return self._re_word_tokenizer
        except __HOLE__:
            self._re_word_tokenizer = re.compile(
                self._word_tokenize_fmt %
                {
                    'NonWord':   self._re_non_word_chars,
                    'MultiChar': self._re_multi_char_punct,
                    'WordStart': self._re_word_start,
                },
                re.UNICODE | re.VERBOSE
            )
            return self._re_word_tokenizer
dataset/ETHPy150Open nltk/nltk/nltk/tokenize/punkt.py/PunktLanguageVars._word_tokenizer_re