def values_per(self, *columns: Set[str]):
    '\n        Counts occurence of unique values in the specified columns.\n        '
    return self._grouped_count('*', *columns, label='values')
Counts occurence of unique values in the specified columns.
def values_per(self, *columns: Set[str]):
    '\n        \n        '
    return self._grouped_count('*', *columns, label='values')