def null_text(variable, nulls=None):
    """
    Deal with variables that are unset (i.e. None) but may be text nulls
    like "None" or ''  - nulls are set by "nulls" input

    :param variable: object, any variable to test for Null
    :param nulls: list of strings or None - if set extra strings that can be
                  a null value
    :return:
    """
    # if variable is None return True
    if variable is None:
        return True
    # if variable is in nulls (and nulls is set) return True
    if isinstance(variable, str):
        if nulls is not None:
            for null in nulls:
                if variable.upper() == null.upper():
                    return True
    # else in all other cases return False
    return False