How to hash a dictionary?

Question

I wanted to know if you could hash a dictionary? Currently playing around with Blockchain! Here's the code I would like to hash:

def add_transactions():

    transaction = {

      "previous_block_hash": previous_block_hash() ,

      "index": increase_index(),

      "item": item(),

      "timestamp": datetime.datetime.now(),

      "sender": get_sender(),

      "receiver": get_receiver()

    }

Wanted to know the best way to apply hashlib to get 256 value a4337bc45a8fc544c03f52dc550cd6e1e87021bc896588bd79e901e2

Answer 1

字典是python中不可散列的数据类型。所以你不能散列字典对象。但是，如果您需要一些校验和，您可以序列化字典，然后计算其哈希（只是一种可以提供帮助的解决方法）。

例如使用jsonpickle和hashlib：

import jsonpickle
import hashlib

dct = {"key": "value"}

serialized_dct = jsonpickle.encode(dct)

check_sum = hashlib.sha256(serialized_dct.encode('utf-8')).digest()

print(check_sum)

更新：

Glich的代码示例不精确，需要这样改进：

import json
import hashlib

s = json.dumps({'test dict!': 42}).encode('utf-8')

print(hashlib.md5(s).digest())