【学习】大文件MD5校验
将大文件分块读取到内存中,每次读取的内容通过update()更新校验值,最终获得完整文件的md5校验值
1 #!python3 2 #coding:utf-8 3 4 ''' 5 This module is coded by Yuning Ju 6 7 Copyright 2018 Yuning Ju 8 9 实现:大文件的MD5校验 10 11 ''' 12 import hashlib,time 13 14 15 def md5_check(fh): 16 ''' 17 Calculate the md5 of files 18 将文件分块读入内存,防止内存溢出 19 20 ''' 21 22 fp.seek(0) 23 fr = fp.read(8096) 24 while fr: 25 yield fr 26 fr = fp.read(8096) 27 else: 28 fp.seek(0) 29 30 31 if __name__ == '__main__': 32 start = time.clock() 33 filename = input('请输入文件路径:') 34 m = hashlib.md5() 35 with open(filename,'rb') as fp: 36 for fr in md5_check(fp): 37 m.update(fr) #逐次更新校验值 38 end = time.clock() 39 print(m.hexdigest(),'\n用时: %.3f s' %(end-start))