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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 get_all_positions(dataset, num_workers=1):
 """ Extracts paragraph identifiers, and positions from a dataset in the NTCIR-11 Math-2, and NTCIR-12 MathIR XHTML5 format. Parameters dataset : Path A path to a dataset. num_workers : int, optional The number of processes that will extract paragraph positions from the dataset. Yields ------- (Path, str, float) A parent directory of a paragraph, the identifier of the paragraph, and an estimate of the position of the paragraph in its parent document. The position is in the range [0; 1). """

    positions = []
    identifiers = tqdm(
        list(get_all_identifiers(dataset)), desc="get_all_positions(%s)" % dataset.name)
    with Pool(num_workers) as pool:
        for directory, identifier, position in pool.map(_get_position_worker, identifiers):
            positions.append((directory, identifier, position))
    for directory, identifier, position in positions:
        yield (directory, identifier, position)