docs: def _progress_hook(self, blocknum, blocksize, totalsize):
          """ Progress hook for urlretrieve. """
          read = blocknum * blocksize
          if totalsize > 0:
              percent = read * 1e2 / totalsize
              s = "\r%d%% %*d / %d" % (
                  percent, len(str(totalsize)), read, totalsize)
              sys.stdout.write(s)
  
              if read >= totalsize:
                  sys.stdout.write("\n")
          else:
              sys.stdout.write("read %d\n" % read)