循环插入查询在第8次迭代后中断

Question

我有一个脚本，它从网页中删除一些数据并将这些数据插入到两个MySQL表中。但每次我的循环在第8次循环后破坏。我的意思是脚本inser 8个新行和脚本用退出代码0完成。select movie_id from movie;后我在rows变量中有99行，但只插入8个元素。我的错误在哪里，我该如何解决？

import MySQLdb

db = MySQLdb.connect(host="...", user="...", passwd="...", db="...")
cursor = db.cursor()

def parse_person(actor_id, movie_id):
    actor = # ...

    sql_insert_actor = """INSERT IGNORE INTO actor (name)
        values ("{0}");""".format(actor.name)
    sql_insert_tv_actor_mapping = """insert ignore into movie_actor_mapping (actor_id, movie_id) values ("{0}", "{1}");""".format(
            cursor.lastrowid,
            movie_id
        )
    try:
        cursor.execute(sql_insert_actor)
        cursor.execute(sql_insert_tv_actor_mapping)
        db.commit()
    except:
        db.rollback()


def parse_persons(actors_list, movie_id):
    for actor in actors_list:
        parse_person(actor.actor_id, movie_id)

try:
    cursor.execute('select movie_id from movie;')
    rows = cursor.fetchall()
    for row in rows:
        movie_id = row[0]
        actors_list = # parse some 
        parse_persons(actors_list, movie_id)
except:
    db.rollback()


db.close()