d to lower case.

        The default value is True.
    replace_space : '_', optional
        Character(s) used in replacement of white spaces.

    Notes
    -----
    Calling an instance of `NameValidator` is the same as calling its
    method `validate`.

    Examples
    --------
    >>> validator = np.lib._iotools.NameValidator()
    >>> validator(['file', 'field2', 'with space', 'CaSe'])
    ('file_', 'field2', 'with_space', 'CaSe')

    >>> validator = np.lib._iotools.NameValidator(excludelist=['excl'],
    ...                                           deletechars='q',
    ...                                           case_sensitive=False)
    >>> validator(['excl', 'field2', 'no_q', 'with space', 'CaSe'])
    ('EXCL', 'FIELD2', 'NO_Q', 'WITH_SPACE', 'CASE')

    )