def bytes_to_human(n):
  symbols = ('K','M','G','T','P','E','Z','Y')
  prefix = {}
  for i,s in enumerate(symbols):
    prefix[s] = 1 << (i + 1) * 10
  for s in reversed(symbols):
    if n >= prefix[s]:
      value = float(n) / prefix[s]
      return '%.1f%s' % (value,s)
  return '%sB' % n

def bytes(bytes):
  if bytes < 1024: #比特
    bytes = str(round(bytes, 2)) + ' B' #字节
  elif bytes >= 1024 and bytes < 1024 * 1024:
    bytes = str(round(bytes / 1024, 2)) + ' KB' #千字节
  elif bytes >= 1024 * 1024 and bytes < 1024 * 1024 * 1024:
    bytes = str(round(bytes / 1024 / 1024, 2)) + ' MB' #兆字节
  elif bytes >= 1024 * 1024 * 1024 and bytes < 1024 * 1024 * 1024 * 1024:
    bytes = str(round(bytes / 1024 / 1024 / 1024, 2)) + ' GB' #千兆字节
  elif bytes >= 1024 * 1024 * 1024 * 1024 and bytes < 1024 * 1024 * 1024 * 1024 * 1024:
    bytes = str(round(bytes / 1024 / 1024 / 1024 / 1024, 2)) + ' TB' #太字节
  elif bytes >= 1024 * 1024 * 1024 * 1024 * 1024 and bytes < 1024 * 1024 * 1024 * 1024 * 1024 * 1024:
    bytes = str(round(bytes / 1024 / 1024 / 1024 / 1024 / 1024, 2)) + ' PB' #拍字节
  elif bytes >= 1024 * 1024 * 1024 * 1024 * 1024 * 1024 and bytes < 1024 * 1024 * 1024 * 1024 * 1024 * 1024 * 1024:
    bytes = str(round(bytes / 1024 / 1024 / 1024 / 1024 / 1024 /1024, 2)) + ' EB' #艾字节
  return bytes
 
if __name__ == '__main__':
  print('0：' + bytes(0))
  print('1：' + bytes(1))
  print('2：' + bytes(10))
  print('3：' + bytes(100))
  print('4：' + bytes(1000))
  print('5：' + bytes(10000))
  print('6：' + bytes(100000))
  print('7：' + bytes(1000000))
  print('8：' + bytes(10000000))
  print('9：' + bytes(100000000))
  print('10：' + bytes(1000000000))
  print('11：' + bytes(10000000000))
  print('12：' + bytes(100000000000))
  print('13：' + bytes(1000000000000))
  print('14：' + bytes(10000000000000))
  print('15：' + bytes(100000000000000))
  print('16：' + bytes(1000000000000000))
  print('17：' + bytes(10000000000000000))
  print('18：' + bytes(100000000000000000))
  print('19：' + bytes(1000000000000000000))
  print('20：' + bytes(10000000000000000000))
  print('20：' + bytes(100000000000000000000))
  print('20：' + bytes(1000000000000000000000))