Question

我已经看过这里的其他4个问题，但仍然不知道将.encode()或.encode('utf-8')放在哪里。我已将其注释掉，以显示我尝试过的各个地方。

import hashlib as hasher

    class Block:
        def __init__(self, index, timestamp, data, previous_hash):
            self.index = index
            self.timestamp = timestamp
            self.data = data 
            self.previous_hash = previous_hash #these four items used to calculate crypHash of each block
            self.hash = self.hash_block() #helps ensure integrity throughout blockchain

        def hash_block(self):
            sha = hasher.sha256() #.encode('utf-8')
            sha.update(str(self.index)+
                str(self.timestamp)+
                str(self.data)+
                str(self.previous_hash)) #.encode() inside brackets
            return sha.hexdigest()

这是回溯（自下而上阅读）：

Traceback (most recent call last):
  File "blockchain.py", line 7, in <module>
    blockchain = [create_genesis_block()]
  File "/media/nobu/win10Files/Blockchain/SnakeCoin/genesis.py", line 8, in create_genesis_block
    return Block(0, date.datetime.now(), "Genesis Block", "0")
  File "/media/nobu/win10Files/Blockchain/SnakeCoin/block.py", line 9, in __init__
    self.hash = self.hash_block() #helps ensure integrity throughout blockchain
  File "/media/nobu/win10Files/Blockchain/SnakeCoin/block.py", line 16, in hash_block
    str(self.previous_hash))
TypeError: Unicode-objects must be encoded before hashing

似乎表明str(self.previous_hash)) #.encode() inside brackets行应为str(self.previous_hash).encode())，但这给了我另一个错误：

Traceback (most recent call last):
  File "blockchain.py", line 7, in <module>
    blockchain = [create_genesis_block()]
  File "/media/nobu/win10Files/Blockchain/SnakeCoin/genesis.py", line 8, in create_genesis_block
    return Block(0, date.datetime.now(), "Genesis Block", "0")
  File "/media/nobu/win10Files/Blockchain/SnakeCoin/block.py", line 9, in __init__
    self.hash = self.hash_block() #helps ensure integrity throughout blockchain
  File "/media/nobu/win10Files/Blockchain/SnakeCoin/block.py", line 16, in hash_block
    str(self.previous_hash).encode())
TypeError: must be str, not bytes

因此，我尝试使用括号将encode()和decode()进行各种组合，但这只会使我在错误之间交替。
因此，我很迷茫，不胜感激。顺便说一句，此代码来自此处的中型文章：Medium Snake Coin

Answer 1

仅bytes个字符串可以散列。 str是Unicode字符串。编码为字节，解码为Unicode。

在您的.update()中，所有四个项目都将转换为str。因此，一旦将它们串联在一起，整个过程就.encode()变成了bytes：

import hashlib as hasher

class Block:
    def __init__(self, index, timestamp, data, previous_hash):
        self.index = index
        self.timestamp = timestamp
        self.data = data 
        self.previous_hash = previous_hash #these four items used to calculate crypHash of each block
        self.hash = self.hash_block() #helps ensure integrity throughout blockchain

    def hash_block(self):
        sha = hasher.sha256()
        to_hash = str(self.index) + str(self.timestamp) + str(self.data) + str(self.previous_hash)
        sha.update(to_hash.encode())
        return sha.hexdigest()

Python TypeError：哈希编码之前必须对Unicode对象进行编码

1 个答案: