└── Blockchain.py


/Blockchain.py:
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 1 | import hashlib
 2 | import time
 3 | 
 4 | class Blockchain:
 5 |     def __init__(self):
 6 |         self.chain = []
 7 |         self.create_block(previous_hash='1', proof=100)
 8 | 
 9 |     def create_block(self, proof, previous_hash):
10 |         block = {
11 |             'index': len(self.chain) + 1,
12 |             'timestamp': time.time(),
13 |             'proof': proof,
14 |             'previous_hash': previous_hash,
15 |         }
16 |         self.chain.append(block)
17 |         return block
18 | 
19 |     def get_previous_block(self):
20 |         return self.chain[-1]
21 | 
22 |     def proof_of_work(self, previous_proof):
23 |         proof = 1
24 |         while not self.valid_proof(proof, previous_proof):
25 |             proof += 1
26 |         return proof
27 | 
28 |     def valid_proof(self, proof, previous_proof):
29 |         guess = f'{previous_proof}{proof}'.encode()
30 |         guess_hash = hashlib.sha256(guess).hexdigest()
31 |         return guess_hash[:4] == '0000'
32 | 
33 | # Example usage
34 | blockchain = Blockchain()
35 | previous_block = blockchain.get_previous_block()
36 | previous_proof = previous_block['proof']
37 | proof = blockchain.proof_of_work(previous_proof)
38 | blockchain.create_block(proof, previous_block['previous_hash'])
39 | 


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