proof_of_work.py

blockchain/proof_of_work.py

@@ -0,0 +1,49 @@
+import hashlib
+import time
+from datetime import datetime
+
+class Block:
+    def __init__(self, index: int, previous_hash: str, data: str, timestamp: str):
+        self.index = index
+        self.previous_hash = previous_hash
+        self.data = data
+        self.timestamp = timestamp
+        self.nonce = 0
+        self.hash = self.calculate_hash()
+
+    def calculate_hash(self) -> str:
+        value = (str(self.index) + str(self.previous_hash) + 
+                 str(self.data) + str(self.timestamp) + str(self.nonce))
+        return hashlib.sha256(value.encode('utf-8')).hexdigest()
+
+    def mine_block(self, difficulty: int) -> None:
+        target = '0' * difficulty
+        while self.hash[:difficulty] != target:
+            self.nonce += 1
+            self.hash = self.calculate_hash()
+        print(f"Block mined: {self.hash}")
+
+class Blockchain:
+    def __init__(self):
+        self.chain = [self.create_genesis_block()]
+        self.difficulty = 4
+
+    def create_genesis_block(self) -> Block:
+        return Block(0, "0", "Genesis Block", datetime.now().isoformat())
+
+    def get_latest_block(self) -> Block:
+        return self.chain[-1]
+
+    def add_block(self, new_block: Block) -> None:
+        new_block.previous_hash = self.get_latest_block().hash
+        new_block.mine_block(self.difficulty)
+        self.chain.append(new_block)
+
+# Example usage
+blockchain = Blockchain()
+blockchain.add_block(Block(1, "", "Block 1 Data", datetime.now().isoformat()))
+blockchain.add_block(Block(2, "", "Block 2 Data", datetime.now().isoformat()))
+
+# Display the blockchain
+for block in blockchain.chain:
+    print(f"Block {block.index} - Hash: {block.hash} - Data: {block.data}")