我有一个类似于以下结构的CSV文件。INDEX,SYMBOL,DATETIMETS,PRICE,SIZE0,A,2002-12-029:30:20,19.75,302001,A,2002-12-029:30:22,19.75,1002,A,2002-12-029:30:22,19.75,3003,A,2002-12-029:30:22,19.75,1004,A,2002-12-029:30:23,19.75,1005,A,2002-12-029:30:23,19.75,1006,A,2002-12-029:30:23,19.75,1007,A,2002-12-029:30:23,19.75,1