python 笔记 之 计算md5值

'''
计算md5值

'''
import codecs
import hashlib
import os

# @CyTime.getFunctionRunTime
def getStringMd5(string): #计算字符串的MD5值
    md5 = hashlib.md5(string.encode()).hexdigest()
    return md5
#计算文件的MD5值:方法一,小文件small
# @CyTime.getFunctionRunTime
def getSmallFileMd5(file):
    if os.path.isfile(file):
        with codecs.open(file, 'rb') as f:
            md5 = hashlib.md5(f.read()).hexdigest()
            return md5

# 计算文件的MD5值:方法二，大文件Large，比方法一快
# @CyTime.getFunctionRunTime
def getLargeFileMd5(file):
    if os.path.isfile(file):
        myhash = hashlib.md5()
        with codecs.open(file, 'rb') as f:
            while 1:
                b = f.read(8096)
                if not b:
                    break
                myhash.update(b)
            md5 = myhash.hexdigest()
            return md5

def demo():
    url = "V:\MyVideo\python\Python 正则表达式.docx"
    print(getStringMd5(url))
    print(getSmallFileMd5(url))
    print(getLargeFileMd5(url))

Windows命令查看文件MD5
certutil -hashfile yourfilename.ext MD5
certutil -hashfile yourfilename.ext SHA1
certutil -hashfile yourfilename.ext SHA256

certutil -hashfile data.csv MD5