def _descendants(node):
    try:
        treepos = node.treepositions()
    except AttributeError:
        return []
    return [node[x] for x in treepos[1:]]
You should override this method
dataset/ETHPy150Open nltk/nltk/nltk/tgrep.py/_descendants--crossover with--dataset/ETHPy150Open shuge/Qt-Python-Binding-Examples/qcommons/qwinutils.py/CustomWin.__init__