Python字节单位转换（将字节转换为K M G T）

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