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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 combine_columns(columns):
 """Combine ``columns`` into a single string. Example: 'example' Args: columns (iterable):
 ordered columns to combine Returns: String of combined columns """

    columns_zipped = itertools.zip_longest(*columns)
    return ''.join(x for zipped in columns_zipped for x in zipped if x)