Код: Выделить всё
import hashlib
import json
from time import time
from flask import Flask, jsonify, request
class Blockchain:
def __init__(self):
self.chain = []
self.current_transactions = []
self.new_block(previous_hash='1', proof=100) # Create the genesis block
def new_block(self, proof, previous_hash=None):
block = {
'index': len(self.chain) + 1,
'timestamp': time(),
'transactions': self.current_transactions,
'proof': proof,
'previous_hash': previous_hash or self.hash(self.chain[-1]),
}
self.current_transactions = []
self.chain.append(block)
return block
def new_transaction(self, sender, recipient, amount):
self.current_transactions.append({
'sender': sender,
'recipient': recipient,
'amount': amount,
})
return self.last_block['index'] + 1
@staticmethod
def hash(block):
block_string = json.dumps(block, sort_keys=True).encode()
return hashlib.sha256(block_string).hexdigest()
@property
def last_block(self):
return self.chain[-1]
# Create a Flask web server
app = Flask(__name__)
# Create an instance of the Blockchain
blockchain = Blockchain()
@app.route('/mine', methods=['GET'])
def mine():
last_block = blockchain.last_block
last_proof = last_block['proof']
proof = blockchain.proof_of_work(last_proof)
blockchain.new_transaction(
sender="0", # This signifies that this node has mined a new coin
recipient="your_address", # Replace with your address
amount=1, # Amount of MyCoin awarded
)
block = blockchain.new_block(proof, blockchain.hash(last_block))
response = {
'message': 'New Block Forged',
'index': block['index'],
'transactions': block['transactions'],
'proof': block['proof'],
'previous_hash': block['previous_hash'],
}
return jsonify(response), 200
@app.route('/transactions/new', methods=['POST'])
def new_transaction():
values = request.get_json()
required = ['sender', 'recipient', 'amount']
if not all(k in values for k in required):
return 'Missing values', 400
index = blockchain.new_transaction(values['sender'], values['recipient'], values['amount'])
response = {'message': f'Transaction will be added to Block {index}'}
return jsonify(response), 201
@app.route('/chain', methods=['GET'])
def full_chain():
response = {
'chain': blockchain.chain,
'length': len(blockchain.chain),
}
return jsonify(response), 200
if __name__ == '__main__':
app.run(host='0.0.0.0', port=5000)
```
### Step 3: Running the Blockchain
1. Save the code in a file named `blockchain.py`.
2. Run the server using the command:
```bash
python blockchain.py
import time
class Block:
def __init__(self, index, proof_no, prev_hash, data, timestamp=None):
self.index = index
self.proof_no = proof_no
self.prev_hash = prev_hash
self.data = data
self.timestamp = timestamp or time.time()
@property
def calculate_hash(self):
block_string = f"{self.index}{self.proof_no}{self.prev_hash}{self.data}{self.timestamp}"
return hashlib.sha256(block_string.encode()).hexdigest()
class BlockChain:
def __init__(self):
self.chain = []
self.construct_genesis()
def construct_genesis(self):
# Create the initial block (genesis block)
pass # Your implementation here
def construct_block(self, proof_no, prev_hash):
# Create a new block and add it to the chain
pass # Your implementation here
@staticmethod
def check_validity():
# Check whether the blockchain is valid
pass # Your implementation here
def new_data(self, sender, recipient, quantity):
# Add a new transaction to the data of the transactions
pass # Your implementation here
@staticmethod
def construct_proof_of_work(prev_proof):
# Protect the blockchain from attack
pass # Your implementation here
@property
def last_block(self):
# Return the last block in the chain
return self.chain[-1]
Подробнее здесь: https://stackoverflow.com/questions/787 ... an-show-me
