def sort_models_topologically(models):
    """Sort models topologically so that parents will precede children."""
    models = set(models)
    seen = set()
    ordering = []
    def dfs(model):
        if model in models and model not in seen:
            seen.add(model)
            for child_model in model._meta.reverse_relations.values():
                dfs(child_model)
            ordering.append(model)  # parent will follow descendants
    # order models by name and table initially to guarantee a total ordering
    names = lambda m: (m._meta.model_name, m._meta.db_table)
    for m in sorted(models, key=names, reverse=True):
        dfs(m)
    return list(reversed(ordering))  # want parents first in output ordering
dataset/ETHPy150Open kuri65536/python-for-android/sl4atools/fullscreenwrapper2/examples/calcount2_example/peewee.py/sort_models_topologically/original