设置断点可以进入 process_item，但是不晓得为什么不能进入 do_insert。Spider closed (finished) 之后整个程序一直卡着。

class MySQLTwistedPipleline(object):
    def __init__(self, dbpool):
        self.dbpool = dbpool
    @classmethod
    def from_settings(cls, settings):
        dbparms = dict(
            host=settings["MYSQL_HOST"],
            db=settings["MYSQL_DBNAME"],
            user=settings["MYSQL_USER"],
            passwd=settings["MYSQL_PASSWORD"],
            charset="utf8",
            cursorclass=DictCursor,
            use_unicode=True,
        )
        dbpool = adbapi.ConnectionPool("MySQLdb", **dbparms)
        return cls(dbpool)
    def process_item(self, item, spider):
        query = self.dbpool.runInteraction(self.do_insert, item)
        query.addErrback(self.handle_error, item, spider)
        return item
    def handle_error(self, failure, item, spider):
        print(failure)
    def do_insert(self, cursor, item):
        insert_sql = """
        insert into article 
        (title, url, url_object_id, front_image_url, front_image_path, tags, content, parise_nums, comment_nums, fav_nums, create_time) 
        VALUES 
        (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
        """
        params = []
        params.append(item.get("title", ""))
        params.append(item.get("url", ""))
        params.append(item.get("url_object_id", ""))
        front_image_url_str = ",".join(item.get("front_image_url", []))
        params.append(front_image_url_str)
        params.append(item.get("front_image_path", ""))
        params.append(item.get("tags", ""))
        params.append(item.get("content", ""))
        params.append(item.get("parise_nums", 0))
        params.append(item.get("comment_nums", 0))
        params.append(item.get("fav_nums", 0))
        params.append(item.get("create_time", "1970-07-01"))
        cursor.execute(insert_sql, tuple(params))

不进入断点，程序也不自动停止。