Python 之字节转换

 # coding: utf-8
 
 def bytes2human(n):
     """
     >>> bytes2human(10000)
     9K
     >>> bytes2human(100001221)
     95M
     """
     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 = int(float(n)/prefix[s])
             return '%s%s' % (value, s)
     return '%sB' % n