错误 IndexError：在我的基本区块链项目上列出索引超出范围

Question

我为我的学校项目编写了一个基本的区块链，但遇到错误，我该如何修复它？

这是我的代码

的链接

blockchain_data.json

{"chain": [{"index": 0, "transactions": [], "timestamp": 1701466704.945516, "previous_hash": "0", "hash": "c6adb22cbafb1763769f2e6b606fb4eeb23e3764c3c545d7f7955fbcb66420b4", "data": "Genesis Block", "nonce": 0, "signature": "\u058a\u0011*\u0016\u000f\u001d\u0010\rFL;\u89c04\u001fl\u0015\u001d\u0002\u0484d[9} Jf1 *;e$\\\u007f0_{\u001d\"8\u0007\\\u01b5&De:\u070f\u00e0@tB\u000fxM\u0018\u8632\u001a<=\u0004<oj'.Wq12>pAuZ\u001fU0\u001a8j\u0001+_\u001f/\u06f9b:I],Y^:*(\ue3f0i1T)aO\u0019t\\K7F\u001eP\u00111\tH\u0003\u0007s\u000f<\u0013l}77XP\u0004\u0001p~\b&Rx"}]}

我发送 http post 请求以将块添加到链中，如下所示

curl -X POST -H "Content-Type: application/json" -d '{"data": "Example Data"}' http://localhost:5000/mine

我希望它将块添加到链中，但给出了这个错误

keys already exists. Skipping...
anahtarlar yuklendi.
anahtarlar yuklendi.
Private RSA key at 0x7FB36406B910
Public RSA key at 0x7FB36406BB50
anahtarlar yuklendi.
anahtarlar yuklendi.
Can't verify chain integrityl!!!
 * Debugger is active!
 * Debugger PIN: 923-375-613
127.0.0.1 - - [10/Dec/2023 22:42:04] "POST /mine HTTP/1.1" 500 -
Traceback (most recent call last):
  File "/home/wkb/PycharmProjects/pythonProject1/venv/lib/python3.11/site-packages/flask/app.py", line 1478, in __call__
    return self.wsgi_app(environ, start_response)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/wkb/PycharmProjects/pythonProject1/venv/lib/python3.11/site-packages/flask/app.py", line 1458, in wsgi_app
    response = self.handle_exception(e)
               ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/wkb/PycharmProjects/pythonProject1/venv/lib/python3.11/site-packages/flask/app.py", line 1455, in wsgi_app
    response = self.full_dispatch_request()
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/wkb/PycharmProjects/pythonProject1/venv/lib/python3.11/site-packages/flask/app.py", line 869, in full_dispatch_request
    rv = self.handle_user_exception(e)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/wkb/PycharmProjects/pythonProject1/venv/lib/python3.11/site-packages/flask/app.py", line 867, in full_dispatch_request
    rv = self.dispatch_request()
         ^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/wkb/PycharmProjects/pythonProject1/venv/lib/python3.11/site-packages/flask/app.py", line 852, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/run/media/wkb/529042782E47F579/scratch.py", line 310, in mine_block
    block_index = blockchain.mine()
                  ^^^^^^^^^^^^^^^^^
  File "/run/media/wkb/529042782E47F579/scratch.py", line 143, in mine
    last_block = self.last_block
                 ^^^^^^^^^^^^^^^
  File "/run/media/wkb/529042782E47F579/scratch.py", line 87, in last_block
    return self.chain[-1]
           ^^^^^^^^^^^^^^
IndexError: list index out of range

Answer 1

错误表明

self.chain

为空，因为此时尚未初始化：

if len(blockchain.chain) == 0:
    blockchain.create_genesis_block()
else:
    blockchain.load_from_file('blockchain_data.json')

逻辑应该是，如果它为空，则

load_from_file

从文件中填充

self.chain

：

if len(blockchain.chain) == 0:
    blockchain.load_from_file('blockchain_data.json')
else:
    blockchain.create_genesis_block()

更正此块后，您可能会遇到新错误：

    166             self.chain = []
    167             for block_data in data['chain']:
--> 168                 block = Block(
    169                     block_data['index'],
    170                     block_data['transactions'],

TypeError: Block.__init__() takes 6 positional arguments but 7 were given

要修复它，您应该向

signature

类的

__init__

方法添加一个可选参数

Block

:

class Block:

    def __init__(self, index, transactions, timestamp, previous_hash, data, signature=None):
        self.index = index
        self.transactions = transactions
        self.timestamp = timestamp
        self.previous_hash = previous_hash
        self.hash = self.previous_hash
        self.data = data
        self.nonce = 0
        self.signature = signature

这是输出：

keys generated and saved succesfully
anahtarlar yuklendi.
Private RSA key at 0x78BAA098DD20
Public RSA key at 0x78BAA0A63FD0
anahtarlar yuklendi.
Can't verify chain integrityl!!!
<__main__.Block object at 0x78baa098eb30>
<__main__.Block object at 0x78baa098eb30>
anahtarlar yuklendi.
zincir kaydedildi!
Block mined successfully. Block index: 6