#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""智能转换 bytes 为 kb/mb/gb/tb/pb...
"""
import math
def convertBytes(bytes, lst=['Bytes', 'KB', 'MB', 'GB', 'TB', 'PB']):
i = int(math.floor( # 舍弃小数点，取小
math.log(bytes, 1024) # 求对数(对数：若 a**b = N 则 b 叫做以 a 为底 N 的对数)
))
if i >= len(lst):
i = len(lst) - 1
return ('%.2f' + " " + lst[i]) % (bytes/math.pow(1024, i))
def main():
lst = ['Bytes', 'KB', 'MB', 'GB', 'TB', 'PB']
bytes = input('Bytes: ')
print convertBytes(bytes, lst)
if __name__ == '__main__':
main()
