python3 程式碼

想說應該比較多人熟悉 python 的語法，我把前四天的區塊鏈的檔案都改成了 python3 版本了，左法邏輯基本上是一樣的，所以可以搭配前幾天看一下喔～

import sys
import time
import hashlib

current_difficulty = 12

# 區塊的 class
class Block:

	# 區塊包含的資料
	def __init__(self, timestamp, data, prevblockhash, hash_value, nonce):
		self.timestamp = timestamp
		self.data = data
		self.prevblockhash = prevblockhash
		self.hash = hash_value
		self.nonce = nonce

# 創建區塊
def CreateBlock(data, prevblockhash):
	b = Block(time.time(), data, prevblockhash, '', 0)
	
	# 進行 POW
	POW = CreatePOW(b, current_difficulty)
	nonce, hash_value = POW.Proof()

	b.hash = hash_value[:]
	b.nonce = nonce

	return b

# 創建創始區塊
def CreateGenesisBlock():
		return CreateBlock("Genesis Block", '')

# 區塊鏈的 class
class Blockchain:
	def __init__(self, block):
		self.blocks = block
	
	# 在區塊鏈上新增區塊
	def AddBlock(self, data):
		prevblock = self.blocks[len(self.blocks) - 1]
		new_block = CreateBlock(data, prevblock.hash)
		self.blocks.append(new_block)

# 創建區塊鏈
def CreateBlockchain():
	return Blockchain([CreateGenesisBlock()])

maxNonce = sys.maxsize

# 創建 POW
class ProofOfWork():
	def __init__(self, block, difficulty, target):
		self.block = block
		self.difficulty = difficulty
		self.target = target

	# 準備資料以方進行 POW
	def PrepareData(self, nonce):
		self.block.timestamp = str(self.block.timestamp)
		data = self.block.prevblockhash + self.block.data + self.block.timestamp + str(self.target) + hex(nonce)
		return data
	
	# 進行證明
	def Proof(self):
		n = 0
		print("Start mining...")
		while n < maxNonce:
			data = self.PrepareData(n)
			s = hashlib.sha256()
			s.update(data.encode())
			s = s.hexdigest()
			print("\r{:s}".format(s), end='')
			if int(s, 16) < self.target:
				break
			else:
				n += 1

		print('\n')
		s = '0' * (64 - len(s)) + s
		return n, s
	
	# 對已被證明的區塊進行驗證
	def Validate(self):
		data = data = self.PrepareData(self.block.nonce)
		s = hashlib.sha256()
		s.update(data.encode())
		s = s.hexdigest()

		isValid = int(s, 16) < self.target
		return isValid
# 創建POW
def CreatePOW(block, difficulty):
	target = 0x10 ** (64 - difficulty/4)
	return ProofOfWork(block, difficulty, target)

# 以下都是操作介面
def Help():
	print("There are 3 operations:")
	print("Type 1 for adding a new Block")
	print("Type 2 for printing the Blockchain")
	print("Type 3 for exiting")

def main():
	print("Welcome to our Blockchain project.")
	print("Enter h for help")

	new_blockchain = CreateBlockchain()
	while True:
		op = input("Enter your command: ")
		if op == 'h':
			print("Printing the help!")
			Help()
		elif op == '1':
			data = input("Enter your data: ")
			new_blockchain.AddBlock(data)
		elif op == '2':
			for b in new_blockchain.blocks:
				print("Prev. hash: {:s}".format(b.prevblockhash))
				print("Data: {:s}".format(b.data))
				print("Hash: {:s}".format(b.hash))
				POW = CreatePOW(b, current_difficulty)
				print("Pow: {:s}".format(str(POW.Validate())))
				print()
		elif op == '3':
			break
		else:
			print("Please Enter h, 1, 2, 3")

if __name__ == '__main__':
	main()

實作截圖