对于给定PTable中的key和value中每一个元素，构造(key, value)对，结果保存在PCollection中 Args: ptable (PTable): 输入PTable **options: 可配置选项 Returns: PCollection: (key, value)对，结果以PCollection表示 >>> from bigflow import transforms >>> _p = _pipeline.parallelize({"A": [2, 3], "B": [4, 5]
(ptable, **options)
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