def labeller(landmarkable, group, label_func):
    new_group = label_func(landmarkable.landmarks[group])
    landmarkable.landmarks[label_func.group_label] = new_group
    return landmarkable
Note: tests integration with lxml.etree
dataset/ETHPy150Open menpo/menpo/menpo/landmark/labels/base.py/labeller--crossover with--dataset/ETHPy150Open python-openxml/opc-diag/tests/test_presenter.py/DescribeItemPresenter.it_can_pretty_format_the_xml_of_its_item