簡單的區塊鏈代碼入門（python演示原理和solidity 的truffle發布）實驗

好久沒回CSDN了
本文是幾個教程的更新和融合，一部分通過python實作展示簡單的區塊鏈結構和程序，一部分用truffle發布簡單的solidity智能合約腳本，算是區塊鏈入門（不算吧，，）

python區塊鏈模擬腳本（本地）

環境 ：
3.7 python
win10

import hashlib

# class Block:
#     def __init__(self, data, prev_hash):
#         self.previous_hash = prev_hash
#         self.data = data
#
#     # calculate hash
#     @property
#     def hash(self):
#         message = hashlib.sha256()
#         message.update(str(self.data).encode('utf-8'))
#         return message.hexdigest()
class Block():
    """"
    """
    def __init__(self,data,prev_hash):
        self.previous_hash = prev_hash
        self.data = data
        self.nonce = ""

    @property
    def hash(self):
        message = hashlib.sha256()
        message.update(str(self.data).encode('utf-8'))
        message.update(str(self.nonce).encode('utf-8'))
        digest = message.hexdigest()
        return digest


# first Block making function
# def create_genesis_block():
#     return Block(data="Genesis Block", prev_hash="")

def create_genesis_block():
    block = Block(data="Genesis Block",prev_hash="")
    pow = ProofOfWork(block)
    nonce, digest = pow.mine()
    print("nonce: " + str(nonce))
    print("digest: " + str(digest))
    return block

class BlockChain():
    def __init__(self):
        self.blocks = [create_genesis_block()]

    def add_block(self,data):
        prev_block = self.blocks[len(self.blocks)-1]
        block = Block(data, prev_block.hash)
        pow = ProofOfWork(block)
        nonce, digest = pow.mine()
        block.nonce = nonce
        self.blocks.append(block)

# class BlockChain():
#     """docstring for BlockChain"""
#
#     def __init__(self):
#         self.blocks = [create_genesis_block()]
#
#     def add_block(self, data):
#         prev_block = self.blocks[len(self.blocks) - 1]
#         new_block = Block(data, prev_block.hash)
#         self.blocks.append(new_block)
#         return new_block


# if __name__ == '__main__':
# 	bc = BlockChain()
#
# 	b1 = bc.add_block["jack send 0.3 btc to Alice"]
# 	b2 = bc.add_block["Alice send 0.1 btc to Tom"]
#
# 	for b in bc.blocks:
# 		print("Prev Hash:{}".format(b.previous_hash))
# 		print("Data:{}".format(b.data))
# 		print("Hash:{}".format(b.hash))
# 		print("\n")

class ProofOfWork():
    def __init__(self,block):
        self.block = block
#mining
    def mine(self):
        # 這次挖礦要讓挖出的散列值開頭4個0
        prefix = '0000'
        i = 0
        while True:
            nonce = str(i)
            message = hashlib.sha256()
            # 被散列化處理的內容，包括資料和nonce（亂數）
            message.update(str(self.block.data).encode('utf-8'))
            message.update(nonce.encode('utf-8'))
            digest = message.hexdigest()
            if digest.startswith(prefix):
                return nonce,digest
            i += 1





bc = BlockChain()

b1 = bc.add_block("jack send 0.3 btc to Alice")
b2 = bc.add_block("Alice send 0.1 btc to Tom")

for b in bc.blocks:
    print("Prev Hash:{}".format(b.previous_hash))
    print("Data:{}".format(b.data))
    print("Hash:{}".format(b.hash))
    print("\n")

truffle的solidity發布到ganathe模擬的以太網

• Ganathe和truffle 安裝和連接
  安裝：
  參考：
  https://www.cnblogs.com/hupeng1234/p/9804209.html
  https://www.bilibili.com/video/BV1ds41177Cy?p=5
  內容更新：
  1.新建專案命令改為 truffle init（原文看到叫創建truffle就不用看了）
  2.metamask （視頻教程出現，檢測用，已經有點老了）連接RPC網路時現在要chainId了，對應的測驗鏈ID為1337（國內居然每一個論壇說過艸），參考連接：https://github.com/MetaMask/metamask-extension/issues/9683
• truffle的使用和第一個solidity檔案
  參考：
  https://blog.csdn.net/a394268045/article/details/79518530
  這個博客基本走得通，但是版本變了腳本需要變一下（現在windows默認下載solidity本地版0.5.16，教程只有4，跑不起）
  改為以下solidity腳本

pragma solidity >=0.5.6<0.7.0;

contract HelloWorld {

    constructor() public{
        
    }

  function sayHello () pure public returns(string memory) {
    return ("Hello World");
  }

  function print(string memory name) pure public returns (string memory) {
    return name;
    }
}

并且注意！！！ 用truffle init 命令創建的 1_initial_migration.js 檔案需要改成如下：

const Migrations = artifacts.require("Migrations");
const HelloWorld = artifacts.require("HelloWorld");

module.exports = function (deployer) {
  deployer.deploy(Migrations);
  deployer.deploy(HelloWorld);
};

不要改成var和.sol，太老了已經不能用了

并且并且注意！！！！
win的引數檔案只有truffle-config，其中的networks和其下的development只需要取消注銷就行，引數具體如下

  networks: {
    // Useful for testing. The `development` name is special - truffle uses it by default
    // if it's defined here and no other network is specified at the command line.
    // You should run a client (like ganache-cli, geth or parity) in a separate terminal
    // tab if you use this network and you must also set the `host`, `port` and `network_id`
    // options below to some value.
    //
    development: {
     host: "127.0.0.1",     // Localhost (default: none)
     port: 7545,            // Standard Ethereum port (default: none)
     network_id: "*",       // Any network (default: none)
    },

其余的基本按照上面鏈接的教程即可，測驗過可以跑了

以上
may the flame guide thee