def _has_vowel(self, term):
for letter in term:<EOL><INDENT>if letter in self._vowels:<EOL><INDENT>return True<EOL><DEDENT><DEDENT>return False<EOL>
Return Porter helper function _has_vowel value.

        Parameters
        ----------
        term : str
            The word to scan for vowels

        Returns
        -------
        bool
            True iff a vowel exists in the term (as defined in the Porter
            stemmer definition)