Python hashlib Tutorial

The hashlib module in Python is used for encryption-related operations, offering many common hash functions such as MD5, SHA1, SHA256, and others. Its usage typically involves a few key steps.

1. import hashlib module: Use the import hashlib statement to import the hashlib module.
2. Create a hash object by using the hashlib.xxx() function to specify a hash object, where xxx can be MD5, SHA1, SHA256, etc.
3. Update the hash object: add the data for hashing calculation using the hash_obj.update(data) method to the hash object, which can be called multiple times.
4. Obtain the hash value: Use the hash_obj.digest() method to get the hash value of the hash object, which returns a binary string. Alternatively, use the hash_obj.hexdigest() method to get the hash value of the hash object in hexadecimal representation.

Here is an example demonstrating how to use hashlib to calculate the MD5 hash value of a string.

import hashlib

data = 'Hello, World!'  # 要进行哈希计算的字符串

# 创建MD5哈希对象
hash_obj = hashlib.md5()

# 更新哈希对象
hash_obj.update(data.encode('utf-8'))

# 获取哈希值的十六进制表示
hash_value = hash_obj.hexdigest()

print(hash_value)

The resulting output from the above example is 6cd3556deb0da54bca060b4c39479839, which is the MD5 hash value of the string “Hello, World!”.

Apart from MD5, other hash functions such as SHA1, SHA256, and others can also be used. Just replace hashlib.md5() with the corresponding hash function.