scrapy Pipeline使用twisted异步实现mysql数据插入

from twisted.enterprise import adbapi
class MySQLAsyncPipeline:
    def open_spider(self, spider):
        db = spider.settings.get('MYSQL_DB_NAME', 'scrapy_default')
        host = spider.settings.get('MYSQL_HOST', 'localhost')
        port = spider.settings.get('MYSQL_PORT', 3306)
        user = spider.settings.get('MYSQL_USER', 'root')
        passwd = spider.settings.get('MYSQL_PASSWORD', 'root')


        self.dbpool = adbapi.ConnectionPool('MySQLdb', host=host, db=db,
                                    user=user, passwd=passwd, port=port, charset='utf8')
                                    
    def close_spider(self, spider):
        self.dbpool.close()


    def process_item(self, item, spider):
        self.dbpool.runInteraction(self.insert_db, item)

        return item


    def insert_db(self, tx, item):
        values = (
            item['f1'],
            item['f2'],
        )

        sql = 'INSERT INTO books VALUES (%s,%s)'
        tx.execute(sql, values)
from twisted.enterprise import adbapi
class