This is mass conversion to the older Excel 97-2003:
import glob
from win32com.client import Dispatch
for file in glob.glob('/home/adam/*.xlsx'):
xl = Dispatch('Excel.Application')
wb = xl.Workbooks.Add(file)
wb.SaveAs(file[:-1], FileFormat=56)
xl.Quit()
2
solved how to convert xlsx files to simple xls for a given folder