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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 grouper(iterable, n, pad_value=None):
 """ Returns a generator of n-length chunks of an input iterable, with appropriate padding at the end. Example: grouper(3, 'abcdefg', 'x') --> ('a','b','c'), ('d','e','f'), ('g','x','x') Inputs: - iterable: The source iterable that needs to be chunkified. - n: The size of the chunks. - pad_value: The value with which the last chunk will be padded. Output: - chunk_gen: A generator of n-length chunks of an input iterable. """

    chunk_gen = (chunk for chunk in zip_longest(*[iter(iterable)]*n, fillvalue=pad_value))
    return chunk_gen