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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 this_and_prev(iterable):
 """Walk an iterable, returning the current and previous items as a two-tuple."""

    try:
        item = next(iterable)
        while True:
            next_item = next(iterable)
            yield item, next_item
            item = next_item
    except StopIteration:
        return