NewFile_address = Location_front + Newfile_date + '.xlsx' OldFile_address = Location_front + Oldfile_date + '.xlsx' print 'Oldfile date is: ' + Oldfile_date print 'Newfile date is: ' + Newfile_date print 'NewFile Month is: ' + Newfile_month print 'OldFile Month is: ' + Old_file_month excel = DispatchEx('Excel.Application') wbG = excel.Workbooks.Open(OldFile_address) wbP = excel.Workbooks.Open(Write_file_address) excel.visible = 0 # note altered sheet name; also .Select is not required wbG.Worksheets(Old_file_month).Copy(Before=wbP.Worksheets('CombinedData')) wbP.Worksheets(Old_file_month).Name = 'OLDDATA' wbX = excel.Workbooks.Open(NewFile_address) wbX.Worksheets(Newfile_month).Copy(Before=wbP.Worksheets('CombinedData')) wbP.Worksheets(Newfile_month).Name = 'NEWDATA' ## no running out display alets excel.DisplayAlerts = 0 excel.RUN('FindNewMPSlines_Macro') excel.RUN('RemoveCompanion') wbP.SaveAs(Save_file_address) excel.Quit() del excel # ensure Excel process ends print 'MPS NewLine has been composed and saved in folder : ' + Save_file_address