code: def prefix_size(size, base=1024):
      '''Return size in B (bytes), kB, MB, GB or TB.'''
      if ARGS.prefix == 'None':
          for i, prefix in enumerate(['', 'ki', 'Mi', 'Gi', 'Ti']):
              if size < pow(base, i + 1):
                  return '{0} {1}B'.format(round(float(size) / pow(base, i), 1),
                                           prefix)
      else:
          try:
              prefix = {'': 0, 'k': 1, 'M': 2, 'G': 3, 'T': 4}[ARGS.prefix]
          except KeyError:
              exit('Invalid prefix.')
          return '{0} {1}B'.format(round(float(size) / pow(base, prefix), 1),
                                   ARGS.prefixf prefix_size(size, base=1024):
      '''Return size in B (bytes), kB, MB, GB or TB.'''
      if ARGS.prefix == 'None':
          for i, prefix in enumerate(['', 'ki', 'Mi', 'Gi', 'Ti']):
              if size < pow(base, i + 1):
                  return '{0} {1}B'.format(round(float(size) / pow(base, i), 1),
                                           prefix)
      else:
          try:
              prefix = {'': 0, 'k': 1, 'M': 2, 'G': 3, 'T': 4}[ARGS.prefix]
          except KeyError:
              exit('Invalid prefix.')
          return '{0} {1}B'.format(round(float(size) / pow(base, prefix), 1),
                                   ARGS.prefix)
docs: Return size in B (bytes), kB, MB, GB or TB.