Created proof_of_work.py

blockchain/proof_of_work.py

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+import hashlib
+import time
+
+def proof_of_work(difficulty: int) -> int:
+    """
+    Simulates a Proof of Work mining process.
+
+    The miner must find a nonce such that the hash of the nonce starts 
+    with a specific number of leading zeros (difficulty).
+
+    Args:
+        difficulty (int): The number of leading zeros required in the hash.
+
+    Returns:
+        int: The nonce value that solves the puzzle.
+
+    Example:
+        >>> result = proof_of_work(2)  # Difficulty of 2 should be fast
+        >>> isinstance(result, int)
+        True
+    """
+    prefix = '0' * difficulty
+    nonce = 0
+    start = time.time()
+    
+    while True:
+        hash_result = hashlib.sha256(f"{nonce}".encode()).hexdigest()
+        if hash_result.startswith(prefix):
+            end = time.time()
+            print(f"Nonce: {nonce}, Hash: {hash_result}, Time: {end - start:.2f}s")
+            return nonce
+        nonce += 1