code: def psdump(self, filename=None, **kargs):
          
          canvas = self.canvas_dump(**kargs)
          if filename is None:
              fname = get_temp_file(autoext=".eps")
              canvas.writeEPSfile(fname)
              subprocess.Popen([conf.prog.psreader, fname+".eps"])
          else:
              canvas.writeEPSfile(filename)
docs: psdump(filename=None, layer_shift=0, rebuild=1)
  Creates an EPS file describing a packet. If filename is not provided a temporary file is created and gs is called.