供应链金融发展过程

import hashlib
import json

class Block:
    def __init__(self, index, previous_hash, timestamp, data, hash):
        self.index = index
        self.previous_hash = previous_hash
        self.timestamp = timestamp
        self.data = data
        self.hash = hash

def calculate_hash(index, previous_hash, timestamp, data):
    value = str(index) + previous_hash + str(timestamp) + json.dumps(data, sort_keys=True)
    return hashlib.sha256(value.encode('utf-8')).hexdigest()

def create_genesis_block():
    timestamp = 1601544000  # Example timestamp
    data = {"transaction": "Genesis Block"}
    hash = calculate_hash(0, "0", timestamp, data)
    return Block(0, "0", timestamp, data, hash)

def create_new_block(previous_block, data):
    index = previous_block.index + 1
    timestamp = int(time.time())
    hash = calculate_hash(index, previous_block.hash, timestamp, data)
    return Block(index, previous_block.hash, timestamp, data, hash)

# Example usage
genesis_block = create_genesis_block()
blockchain = [genesis_block]
previous_block = blockchain[0]

num_blocks_to_add = 20
for i in range(0, num_blocks_to_add):
    new_data = {"transaction": f"Transaction {i+1}", "sender": "Alice", "receiver": "Bob", "amount": 100}
    new_block = create_new_block(previous_block, new_data)
    blockchain.append(new_block)
    previous_block = new_block

# Print blockchain
for block in blockchain:
    print(f"Index: {block.index}, Hash: {block.hash}, Data: {block.data}")