# Created on savesnippets.com · https://savesnippets.com/HDNJSlTRTS2W4a
from concurrent.futures import ProcessPoolExecutor
import hashlib

def heavy(n: int) -> str:
    """Pure-CPU work — many threads would serialize on the GIL."""
    h = hashlib.sha256(b"seed").digest()
    for _ in range(n):
        h = hashlib.sha256(h).digest()
    return h.hex()[:12]

if __name__ == "__main__":
    inputs = [200_000] * 8
    with ProcessPoolExecutor() as pool:
        for digest in pool.map(heavy, inputs):
            print(digest)
    # On a 4-core machine: ~4x faster than threads for this kind of work