def hexify(self, text: str = "^^^^", upper: bool = False) -> str:
        """Generate a string with each circumflex ('^') in ``text``
        replaced with a random hexadecimal character.

        By default, ``upper`` is set to False. If set to ``True``, output
        will be formatted using uppercase hexadecimal characters.

        :sample: text='MAC Address: ^^:^^:^^:^^:^^:^^'
        :sample: text='MAC Address: ^^:^^:^^:^^:^^:^^', upper=True
        """
        letters = string.hexdigits[:-6]
        if upper:
            letters = letters.upper()
        return _re_cir.sub(lambda x: self.random_element(letters), text)
Generate a string with each circumflex ('^') in ``text``
        replaced with a random hexadecimal character.

        By default, ``upper`` is set to False. If set to ``True``, output
        will be formatted using uppercase hexadecimal characters.

        :sample: text='MAC Address: ^^:^^:^^:^^:^^:^^'
        :sample: text='MAC Address: ^^:^^:^^:^^:^^:^^', upper=True
        
faker/providers/__init__.py