def set_index(self, idx):
        old_index = self.cur_index
        if 0 <= self.num_children() < idx:
            self.cur_index = idx
            child = self.children[idx]
            #child.focus()

            if old_index != idx:
                self.make_callback('page-switch', child)
dataset/ETHPy150Open ejeschke/ginga/ginga/gw/Desktop.py/SymmetricGridWidget.set_index/swapped operands of `<`