老师我这图片下载不了

pipelines.py
# Define your item pipelines here
#
# Don't forget to add your pipeline to the ITEM_PIPELINES setting
# See: https://docs.scrapy.org/en/latest/topics/item-pipeline.html


# useful for handling different item types with a single interface
from itemadapter import ItemAdapter
import pymongo
from scrapy.exceptions import DropItem
from scrapy.pipelines.images import ImagesPipeline

class TubatuScrapyProjectPipeline:
    def __init__(self):
        myclient = pymongo.MongoClient("mongodb://106.12.9.193:27017", username="admin", password="123456")
        mydb = myclient['db_tubatu']
        self.mycollection = mydb['collection_tubatu']


    def process_item(self, item, spider):
        data = dict(item)
        self.mycollection.insert_one(data)
        return item

# 自定义的图片下载类需要继承于ImagesPipeline
class TubatuImagePipeline(ImagesPipeline):
    # def get_media_requests(self, item, info):
    #     # 根据image_urls中指定URL爬取
    #     pass

    def item_completed(self, results, item, info):
        # 图片下载完毕之后，处理结果的，返回是一个二元组
        # (success, image_info_or_failure)
        image_paths = [x['path'] for ok, x in results if ok]
        if not image_paths:
            raise DropItem('Item contains no images')
        return item


    def file_path(self, request, response=None, info=None):
        url = request.url
        file_name = url.split('/')[-1]

        return file_name

这是我pipelines文件的代码，运行以后存储到了数据库但是没有解析图片下载，也没有帮错