在BigQueryGetDataOperator中获取数据的操作不返回可迭代对象，解决方法是通过修改Airflow的代码来实现返回可迭代对象的功能，具体代码见下：

代码示例：

from airflow.contrib.operators import bigquery_get_data
from airflow.contrib.hooks import bigquery_hook
from typing import List, Tuple

# override the BigQueryGetDataOperator to return an iterable object
class IterBigQueryGetDataOperator(bigquery_get_data.BigQueryGetDataOperator):
    def execute(self, context):
        # call the parent execute method
        super().execute(context)
        # create the big query hook
        hook = bigquery_hook.BigQueryHook(
            bigquery_conn_id=self.gcp_conn_id,
            delegate_to=self.delegate_to
        )
        # execute the query and fetch data
        conn = hook.get_conn()
        cursor = conn.cursor()
        cursor.execute(self.sql, self.parameters)
        rows = cursor.fetchall()
        # yield the rows to create an iterable object
        for row in rows:
            yield row

# use the IterBigQueryGetDataOperator to retrieve your data
class MyTask(Task):
    def __init__(self, sql: str):
        self.sql = sql

    def run(self):
        op = IterBigQueryGetDataOperator(
            task_id='my_task',
            bigquery_conn_id='bigquery_default',
            sql=self.sql,
        )
        data: List[Tuple] = []
        for row in op.execute(context={}):
            # do something with the row data
            data.append(row)