我想从每个字段的开头和结尾删除双引号'"'。我正在尝试在pig身上应用正则表达式，但似乎不起作用输入:(main_170521230001.csv,"9","2017-05-2123:00:01.472636")(main_170521230001.csv,"91","2017-05-2123:00:01.472636")(main_170521230001.csv,"592","2017-05-2123:00:01.472636")pig脚本:raw=LOAD'/data/csv'usingPigStorage(',','-tagFile')as(fn:chararray,gid:c