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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def flatten(d, parent_key='', sep='__'):
 """ flattens the dict into a one dimensional dictionary :param d: multidimensional dict :param parent_key: replaces from the parent key :param sep: the separation character used when fattening. the default is __ :return: the flattened dict """

    # http://stackoverflow.com/questions/6027558/flatten-nested-python-dictionaries-compressing-keys
    if type(d) == list:
        flat = []
        for entry in d:
            flat.append(flatten(entry, parent_key=parent_key, sep=sep))
        return flat
    else:
        items = []
        for k, v in d.items():
            new_key = parent_key + sep + k if parent_key else k

            if isinstance(v, collectionsAbc.MutableMapping):
                items.extend(flatten(v, new_key, sep=sep).items())
            else:
                items.append((new_key, v))


        return dict(items)