Hash a large file in Python

large-file-hash.py

import hashlib as hash

# Specify how many bytes of the file you want to open at a time
BLOCKSIZE = 1024 * 1024 * 8  # 8mb

def hash_file(fname: str):
    sha = sha256()
    with open(fname, 'rb') as fh:
        while buff := fh.read(BLOCKSIZE):
            sha.update(buff)
    return sha.hexdigest()

print(hash_file('some_file.iso'))