def _MapVowels(cls, string, also_p=False):
        """
        Return a copy of ``string`` where characters that exist as keys in
        cls._VOWELS have been replaced with the corresponding value.  If
        also_p is True, this function will also change capital P characters
        into a Hebrew character Qof.
        """
        return cls._PSUB_RE.sub(cls.Repl, string)