A simple Excel to PDF Converter

This is a simple PDF Converter which watches in a directory for
incoming Excel documents and converts them to PDF. Ghostscript and a
Postscript printer has to be installed.

path_to_watch = "D:\\share\\"


before = dict ([(f, None) for f in os.listdir (path_to_watch)])
def convert(filename):
    tmpfile = path_to_watch + 'tmp\\'+filename+'.ps'
    if filename[-3:]=='xls':
        pythoncom.CoInitializeEx(pythoncom.COINIT_APARTMENTTHREADED)
        myExcel = win32com.client.DispatchEx('Excel.Application')
        Excel = myExcel.Workbooks.Open(path_to_watch+filename, 0, False, 2)
        Excel.PrintOut(1, 5000, 1, False, 'Rumborak PDF-Writer Plus 1.0 RC5', \
          True, False, tmpfile)
        Excel.Saved = 1
        Excel.Close()
        myExcel.Quit()
        del Excel
        del myExcel
        os.popen('c:\\gs\\gs8.15\\bin\\gswin32c.exe -sDEVICE=pdfwrite -r300 -dNOPAUSE \
           -dBATCH -dSAFER -sPAPERSIZE=a4 \
           -sOutputFile="'+path_to_watch+filename+'.pdf" "'+tmpfile+'"')
        #os.remove(path_to_watch+filename)
        os.remove(tmpfile)
        pythoncom.CoUninitialize()
while 1:
  time.sleep (0.1)
  after = dict ([(f, None) for f in os.listdir (path_to_watch)])
  added = [f for f in after if not f in before]
  if added and added[0][-3:]=='xls':
      starttime = time.clock()
      print "File ", ", ".join (added), "added to queue"
      convert(added[0])
      stoptime = time.clock()
      print "OK. It took", stoptime-starttime, 'seconds.\n'
  before = after