我有pandas数据帧df1和df2(df1是vanila数据帧，df2由“STK_ID”和“RPT_Date”索引):>>>df1STK_IDRPT_DateTClosesalesdiscount0000568200603313.695.975NaN1000568200606309.1410.143NaN2000568200609309.4913.854NaN30005682006123115.8419.262NaN40005682007033117.006.803NaN50005682007063026.3112.940NaN60005682007093039.1219.977Na
