Hi, I'm introducing the following code to get the data via api. There are many row that are empty. There will be some code that I can put so that the empty data is put by N.A and separated by ","

ek.get_timeseries(['AGR.BA','ALU.BA','APBR.BA','AUS.BA','HI.BA','MA.BA','BPAT.BA','BYMA.BA', 'CAMb.BA','CAO.BA','CARC.BA','CAU.BA','CEC.BA','CEL.BA','CEPU.BA','CLA.BA', 'COL.BA','COM.BA','CON.BA','CPS.BA','CRE.BA','CVH.BA','DOM.BA','DYC.BA', 'ECO.BA','EDLH.BA','EDN.BA','EDSH.BA','EMD.BA','ESM.BA','FER.BA','FIP.BA', 'FRA.BA','GAR.BA','GBA.BA','GFG.BA','GRM.BA','HARG.BA','HAVH.BA','INA.BA', 'INR.BA','INU.BA','INVJ.BA','IRCP.BA','IRS.BA','LED.BA','LOMA.BA','LON.BA', 'MERA.BA','MET.BA','MIR.BA','MOL.BA','MOLA.BA','MOR.BA','OEST.BA','PAM.BA', 'PAT.BA','PETR.BA','PGR.BA','POL.BA','PSU.BA','QUI.BA','REP.BA','RICH.BA', 'RIG.BA','RIO.BA','ROS.BA','SEI.BA','SMI.BA','STD.BA','SUPV.BA','TEC2.BA', 'TEF.BA','TENA.BA','TGLT.BA','TGNC.BA','TGS2.BA','TRA.BA','TXAR.BA','VAL.BA', 'YPFD.BA','YPFD.BA'], start_date='2000-01-01' , end_date='2018-01-01')

df.to_csv('galicia_2016_20128.csv')