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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 _prepend_row_index(rows, index):
 """Add a left-most index column."""

    if index is None or index is False:
        return rows
    if len(index) != len(rows):
        print('index=', index)
        print('rows=', rows)
        raise ValueError('index must be as long as the number of data rows')
    rows = [[v] + list(row) for v, row in zip(index, rows)]
    return rows