5.1 hashlib.py

5.1 hashlib.py
#!/usr/bin/python
# -*- encoding: utf-8

import hashlib


if __name__ == "__main__":
    md5 = hashlib.md5()
    md5.update('This is a sentence.'.encode(encoding='utf-8'))
    md5.update('This is a second sentence.'.encode())
    print (u'不出意外，这个将是“乱码”：', md5.digest())
    print (u'MD5:', md5.hexdigest())

    md5 = hashlib.md5()
    md5.update('This is a sentence.This is a second sentence.')
    print (u'MD5:', md5.hexdigest())
    print (md5.digest_size, md5.block_size)
    print ('------------------')

    sha1 = hashlib.sha1()
    sha1.update('This is a sentence.')
    sha1.update('This is a second sentence.')
    print (u'不出意外，这个将是“乱码”：', sha1.digest())
    print (u'SHA1:', sha1.hexdigest())

    sha1 = hashlib.sha1()
    sha1.update('This is a sentence.This is a second sentence.')
    print (u'SHA1:', sha1.hexdigest())
    print (sha1.digest_size, sha1.block_size)
    print ('=====================')

    md5 = hashlib.new('md5', 'This is a sentence.This is a second sentence.')
    print (md5.hexdigest())
    sha1 = hashlib.new('sha1', 'This is a sentence.This is a second sentence.')
    print (sha1.hexdigest())

    print (hashlib.algorithms)

Q1:

md5.update('This is a sentence.')
TypeError: Unicode-objects must be encoded before hashing

As1:
注意update()必须指定要加密的字符串的字符编码
解决办法：

    md5.update('This is a sentence.'.encode(encoding='utf-8'))
    md5.update('This is a second sentence.'.encode())

相关知识
str.encode()

def encode(self, encoding: str = 'utf-8', errors: str = 'strict') Inferred type: (self: str, encoding: str, errors: str) -> bytes

参数：encoding = 'utf-8' 表示以utf-8编码，即将str对象以你选定的编码方式进行编码，errors= 默认为strict，即会抛出编码异常的错误UnicodeEncodeError，可用ignore忽略

md5.update()
sha1.update()
hashlib.new()

都需要指定要加密的字符串的字符编码

hashlib 是一个集成hash加密或者md5加密以及sha1(), sha224(), sha256(), sha384(), sha512(), blake2b(), and blake2s(). md5()的库
主要功能是将字符串进行加密，或者对信息进行摘要。
MD5主要对于任意长度的信息，经过MD5 算法都能得到一段长度为128bit的摘要