你可以使用Custom Retry Middleware来做到这一点，你只需要覆盖process_response当前Retry Middleware的方法即可：

from scrapy.downloadermiddlewares.retry import RetryMiddleware
from scrapy.utils.response import response_status_message


class CustomRetryMiddleware(RetryMiddleware):

    def process_response(self, request, response, spider):
        if request.meta.get('dont_retry', False):
            return response
        if response.status in self.retry_http_codes:
            reason = response_status_message(response.status)
            return self._retry(request, reason, spider) or response

        # this is your check
        if response.status == 200 and response.xpath(spider.retry_xpath):
            return self._retry(request, 'response got xpath "{}"'.format(spider.retry_xpath), spider) or response
        return response

然后启用它，而不是默认RetryMiddleware的settings.py：

DOWNLOADER_MIDDLEWARES = {
    'scrapy.downloadermiddlewares.retry.RetryMiddleware': None,
    'myproject.middlewarefilepath.CustomRetryMiddleware': 550,
}

现在，你有了一个中间件，你可以在其中配置，xpath以使用属性在Spider内部重试retry_xpath：

class MySpider(Spider):
    name = "myspidername"

    retry_xpath = '//h2[@class="tadasdop-cat"]'
    ...

当“项目”的字段为空时，这不一定会重试，但是你可以在此retry_xpath属性中指定该字段的相同路径以使其起作用。