Scrapy spider不调用“回调”函数

我试图用下面的爬行器执行爬行,但它不调用“回调”函数。我的蜘蛛:

from scrapy.spiders import CrawlSpider, Rule
from scrapy.linkextractors import LinkExtractor


class ScreenerSpider(CrawlSpider):
    name = 'screener'
    allowed_domains = ['finviz.com']
    start_urls = ['https://finviz.com/screener.ashx']

    rules = [
        Rule(LinkExtractor(allow=['https://finviz.com/screener.ashx?v=111&r=[0-9]{2}']),
             callback='parse_screener', follow=True)
    ]


    def parse_screener(self, response):
        self.logger.warning('lalala')

当我运行这个爬行器时,它不会在终端中打印“lalala”,也就是说,不会调用“parse\u screener”函数。我编写了这个蜘蛛,正如文档中所示。有什么问题吗?