无法在Apache airflow中使用导入和使用MySqlOperator

from airflow.models import BaseOperator
from airflow.utils.decorators import apply_defaults
import mysql.connector

class MySQLOperator(BaseOperator):
    @apply_defaults
    def __init__(self, sql, conn_id='mysql_default', *args, **kwargs):
        super(MySQLOperator, self).__init__(*args, **kwargs)
        self.sql = sql
        self.conn_id = conn_id

    def execute(self, context):
        # 连接MySQL数据库
        conn = mysql.connector.connect(
            host='mysql_host',
            user='mysql_user',
            password='mysql_password',
            database='mysql_database'
        )
        cursor = conn.cursor()

        # 执行SQL语句
        cursor.execute(self.sql)

        # 提交事务
        conn.commit()

        # 关闭连接
        cursor.close()
        conn.close()

from airflow import DAG
from airflow.operators.dummy_operator import DummyOperator
from mysql_operator import MySQLOperator

default_args = {
    'owner': 'airflow',
    'start_date': datetime(2022, 1, 1),
}

with DAG('mysql_dag', default_args=default_args, schedule_interval='@daily') as dag:
    start = DummyOperator(task_id='start')

    mysql_task = MySQLOperator(
        task_id='mysql_task',
        sql='SELECT * FROM table',
        conn_id='mysql_conn'
    )

    end = DummyOperator(task_id='end')

    start >> mysql_task >> end