def handy_ruler(pkg_name):
    """Create a handy ruler.

    Parameters:
    ----------
    pkg_name : {str}
        Name of program
    Returns
    -------
    list
        Returns single element list with 'handy ruler'.

    """
    ruler_intend = len(pkg_name) * ' '
    ruler_start = '|-----handy-ruler'  # 17 chars
    ruler_extender = (79 - len(ruler_intend + ruler_start) - 1) * '-'
    ruler_end = '|'
    handy_ruler = ruler_intend + ruler_start + ruler_extender + ruler_end
    # cause .split() removes whitespaces
    handy_ruler = [handy_ruler]
    return handy_ruler