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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _sha256(path):
 """Calculate the sha256 hash of the file at path."""

    sha256hash = hashlib.sha256()
    chunk_size = 8192
    with open(path, "rb") as buff:
        while True:
            buffer = buff.read(chunk_size)
            if not buffer:
                break
            sha256hash.update(buffer)
    return sha256hash.hexdigest()