hashlib模块

import hashlib
# 能够把一个字符串数据类型的变量，转换成定长的密文的字符串,每一个字符都是十六进制数

# md5 结果为32位字符串，每个字符都是十六进制
# 注意：如果要对多个字符串计算md5，一定要实例化多个MD5对象 md5_obj = hashlib.md5(bytes('任意字符串作为盐',encoding='utf-8'))
s = 'alex3714'
md5_obj = hashlib.md5(bytes('任意字符串作为盐',encoding='utf-8'))

md5_obj.update(bytes(s,encoding='utf-8'))
m = md5_obj.hexdigest()
print(m)

# sha1 结果为40位字符串，每个字符都是十六进制.用法跟md5一样 只需要把md5改成sha1
s = 'alex3714'
sha1_obj =hashlib.sha1(bytes('任意字符串作为盐',encoding='utf-8'))
sha1_obj.update(bytes(s,encoding='utf-8'))
s = sha1_obj.hexdigest()
print(s)

# 大文件md5 注意：同一个文件的时候一定要用同一个md5的实例化对象 25cd4f5e603e0da5ff5b12e445503052
def md5_file(file_name,each_size=1024):
    import os
    md5_obj = hashlib.md5()
    file_size = os.path.getsize(file_name)
    with open(file_name,'rb') as f:
        count = 0
        while count < file_size:
            if count + each_size < file_size:
                line = f.read(each_size)
                count += each_size
            else:
                line = f.read(file_size-count)
                count = file_size
            md5_obj.update(line)
    m = md5_obj.hexdigest()
    return m
def md5_file_compare(file1,file2,each_size=1024):
    file1_md5 = md5_file(file1,each_size)
    file2_md5 = md5_file(file2,each_size)
    return file1_md5,file2_md5,file1_md5==file2_md5
file1 = '测试用的文件.mp4'
file2 = 'os模块.ipynb'
print(md5_file_compare(file1,file2,each_size=1024))