code: def prt_detail(self):
          
          screen = [
              "Detail info of %s: " % self.abspath,
              "total size = %s" % string_SizeInBytes(self.size_total),
              "number of sub folders = %s" % self.num_folder_total,
              "number of total files = %s" % self.num_file_total,
              "lvl 1 file size = %s" % string_SizeInBytes(self.size_current),
              "lvl 1 folder number = %s" % self.num_folder_current,
              "lvl 1 file number = %s" % self.num_file_current,
          ]
          print("\n".join(screen))
docs: Nicely print stats information.