def _new_gwyitem(cfunc, item_key, cvalue):
    """ Create GWY file item

    Args:
        cfunc (<C function>): C function to create a new GWY file item,
                              (e.g. lib.gwyfile_item_new_int32)
        item_key (string): GWY file item name
        cvalue: value of the GWY file item value in C representation

    Returns:
        gwyitem (<cdata GwyfileItem*>): new GWY file item
        """
    gwyitem = cfunc(item_key.encode('utf-8'), cvalue)
    return gwyitem