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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, sep='.'):
 """Flatten a data structure into tuples"""


    def _flatten(e, parent_key='', sep='.'):
        import collections

        prefix = parent_key + sep if parent_key else ''

        if isinstance(e, collections.MutableMapping):
            return tuple((prefix + k2, v2) for k, v in e.items() for k2, v2 in _flatten(v, k, sep))
        elif isinstance(e, collections.MutableSequence):
            return tuple((prefix + k2, v2) for i, v in enumerate(e) for k2, v2 in _flatten(v, str(i), sep))
        else:
            return (parent_key, (e,)),

    return tuple((k, v[0]) for k, v in _flatten(d, '', sep))