'Do some basic validation for the value (empty, non-printable chars).
Arguments:
value: The value to check.'

def _basic_validation(self, value):

    if (not value):
        if self.none_ok:
            return
        else:
            raise configexc.ValidationError(value, 'may    not    be    empty!')
    if any((((ord(c) < 32) or (ord(c) == 127)) for c in value)):
        raise configexc.ValidationError(value, 'may    not    contain    unprintable    chars!')
