code: def _make_ltcube_file_list(ltsumfile, num_files):
      
      outbasename = os.path.basename(ltsumfile)
      lt_list_file = ltsumfile.replace('fits', 'lst')
      outfile = open(lt_list_file, 'w')
      for i in range(num_files):
          split_key = "%06i" % i
          output_dir = os.path.join(NAME_FACTORY.base_dict['basedir'], 'counts_cubes', split_key)
          filepath = os.path.join(output_dir, outbasename.replace('.fits', '_%s.fits' % split_key))
          outfile.write(filepath)
          outfile.write("\n")
      outfile.close()
      return '@' + lt_list_file
docs: Make the list of input files for a particular energy bin X psf type