我有一个数据框:costmonthparaprod_code040201060AAAIAI432016-01-010402040201060AAAIAJ452016-02-010402040201060AAAIAI462016-03-010402040201060AAAIAI412016-01-010402040201060AAAIAI482016-02-010402如何遍历行，并获取每一行的索引值？d={'prod_code':['040201060AAAIAI','040201060AAAIAJ','040201060AAAIAI','040201060AAAIAI','04020