爬虫保存不到pipelines文件，没有执行

爬取到文件不保存到pipelines文件中，但是管道也开启了
pipelines文件

import json

class ItbearPipeline:
    f = None
    def process_item(self, item, spider):
        def open_spider(self, spider):
            print("开始")
            self.f = open("./house.csv", mode='w', encoding="utf-8")

        def process_item(self, item, spider):
            item = dict(item)
            item_str = json.dumps(item, ensure_ascii=False) + "\n"
            self.f.write(item_str)
            return item

        def close_spider(self, spider):
            print("完毕")
            self.f.close()

settings文件

ROBOTSTXT_OBEY = False
LOG_LEVEL = 'ERROR'
ITEM_PIPELINES = {
   'itbear.pipelines.ItbearPipeline': 300,
}

.py文件

```python
import scrapy
from itbear.items import ItbearItem

class IbearSpider(scrapy.Spider):
    name = 'ibear'
    #allowed_domains = ['www.xxx.com']
    start_urls = ['http://www.techweb.com.cn/news/']

    def parse(self, response):
        node_list = response.xpath('//div[@class="list_con"]/div[@class="picture_text"]')
        for node in node_list:
            link = node.xpath('./div[@class="text"]/a/@href').extract_first()
            yield scrapy.Request(link, callback=self.parse_detail)  # 访问
            #print(link)


    def parse_detail(self, response):
        item = ItbearItem()  # item对象
        item['name'] = response.xpath(
            '//div[@class="content"]/div[@class="main_c"]/h1/text()').extract_first()
        #print(item['name'])
        item['date'] = response.xpath(
            '//div[@class="content"]/div[@class="main_c"]/div[@class="article_info"]/div[@class="infos"]/span['
            '@class="time"]/text()').extract_first()
        #print(item['date'])
        item['content'] = response.xpath(
             '//div[@class="content"]/div[@class="main_c"]/div[@id="content"]/p/text()').extract_first()
        # print(item['content'])
        yield item

运行结果 直接略过了pipelines文件

麻烦大家帮忙解答!

你在parse函数的for循环里面print看看是否有执行循环