def add_text(text_list,sep):
    """
    return int, number of digits to display

    Parameters
    ----------
    text_list : list
        list of text elements to concat
    sep: str
        separatator

    Returns
    -------
    int
        number of digits
    """
    clean_list = [x for x in text_list if x not in ['', None]]
    return sep.join(clean_list)