def _split_privs(privspec):
    """Split the aclitem into three parts

    :param privspec: privilege specification (aclitem)
    :return: tuple with grantee, privilege codes and granto
    """
    usr, prvgrant = privspec.split('=')
    if usr == '':
        usr = 'PUBLIC'
    privcodes, grantor = prvgrant.split('/')
    return usr, privcodes, grantor
