docs: def human_size(s, factor):
      """
      :s: size
      :factor: 1000 or 1024
      """
      unit = 'B'
      if s > factor:
          s /= factor
          unit = 'KB'
      if s > factor:
          s /= factor
          unit = 'MB'
      if s > factor:
          s /= factor
          unit = 'GB'
      if s > factor:
          s /= factor
          unit = 'TB'
      return '%.2f %s' % (s, unit)