排出使用FILE_LOAD write方法的数据流作业是否确保所有元素都已写入？

try:
    with open('data.txt', 'w') as file:
        for item in data_stream:
            file.write(f"{item}\n")
    # 提交事务
    file.flush()
    os.fsync(file.fileno())
except Exception as e:
    # 回滚事务
    print(f"Error writing data: {e}")

checkpoint = 0
try:
    with open('data.txt', 'a') as file:
        for i, item in enumerate(data_stream):
            file.write(f"{item}\n")
            checkpoint = i + 1
            if i % 1000 == 0:  # 每写入1000条记录保存一次检查点
                save_checkpoint(checkpoint)
except Exception as e:
    print(f"Error writing data: {e}")
    restore_from_checkpoint(checkpoint)

import hashlib

def calculate_checksum(file_path):
    sha256_hash = hashlib.sha256()
    with open(file_path, "rb") as f:
        for byte_block in iter(lambda: f.read(4096), b""):
            sha256_hash.update(byte_block)
    return sha256_hash.hexdigest()

expected_checksum = "expected_sha256_hash"
actual_checksum = calculate_checksum('data.txt')
if expected_checksum == actual_checksum:
    print("Data integrity verified.")
else:
    print("Data integrity check failed.")