可以通过自定义 Operator 来实现只传输一个文件并指定文件名。首先需要继承 GCSToS3Operator，然后重写 execute 函数，在函数中调用 GCSHook 和 S3Hook 进行文件传输，同时指定目标 S3 上的文件名。

示例代码如下所示：

from airflow.contrib.operators.gcs_to_s3 import GCSToS3Operator
from airflow.providers.amazon.aws.hooks.s3 import S3Hook
from airflow.providers.google.cloud.hooks.gcs import GCSHook

class GCSFileToS3Operator(GCSToS3Operator):
    
    def __init__(
        self,
        source_bucket: str,
        source_object: str,
        destination_bucket: str,
        destination_object: str,
        **kwargs,
    ):
        super().__init__(
            source_bucket=source_bucket,
            source_object=source_object,
            destination_bucket=destination_bucket,
            destination_object=destination_object,
            **kwargs,
        )
        self.source_bucket = source_bucket
        self.source_object = source_object
        self.destination_bucket = destination_bucket
        self.destination_object = destination_object

    def execute(self, context):
        gcs_hook = GCSHook()
        s3_hook = S3Hook(aws_conn_id=self.aws_conn_id)

        # Download the file from GCS to local
        tmp_file = self._build_gcs_uri(self.source_bucket, self.source_object)
        self.log.info("Downloading from %s", tmp_file)
        with NamedTemporaryFile() as f:
            gcs_hook.download(bucket_name=self.source_bucket, object_name=self.source_object, filename=f.name)

            f.seek(0)

            # Upload the file to S3
            s3_hook.load_file(
                filename=f.name,
                key=self.destination_object,
                bucket_name=self.destination_bucket
            )

        self.log.info("File has been uploaded to %s/%s", self.destination_bucket, self.destination_object)

在 DAG 文件中使用自定义 Operator，只需要指定 GCS 上的文件路径和 S3 上的文件名即可：

from datetime import datetime
from airflow import DAG
from