def pk_list_to_dict(pk_list):
    """ convert list of multi pk to dict

    ['id', 1, 'id2', 22, 'foo', 'bar'] -> {'foo': 'bar', 'id2': 22, 'id': 1}
    """
    if pk_list and len(pk_list) % 2 == 0:
        return dict(zip(pk_list[::2], pk_list[1::2]))
    return None
