Python计算大文件crc32值

直接看代码吧☺

#!usr/bin/env python  #-*- coding:utf-8 -*-  """ @author: guoqianqian @file: mycrc32.py @time: 2017/07/06 @desc: """import zlibimport osimport sysdef crc32(filepath):    block_size = 1024 * 1024    crc = 0    try:        fd = open(filepath, 'rb')        while True:            buffer = fd.read(block_size)            if len(buffer) == 0: # EOF or file empty. return hashes                fd.close()                if sys.version_info[0] < 3 and crc < 0:                    crc += 2 ** 32                return crc#返回的是十进制的值            crc = zlib.crc32(buffer, crc)    except Exception as e:        if sys.version_info[0] < 3:            error = unicode(e)        else:            error = str(e)        return 0, errorif __name__ == "__main__":    crc = crc32("./test")    print hex(crc)