由于 process_links，Scrapy 陷入无限循环

Question

我正在使用 scrapy 2.1.0 并希望通过 link_filtering 向每个请求添加参数。这可行，但我确实遇到了无限循环，因为重复过滤器似乎受到了影响。

rules = (
    Rule(
        LinkExtractor(
            allow=['^(example)?\/(?!ratgeber)[a-z-]+\/(\?p=\d+)?$'],
            restrict_xpaths=(['//div[@class="sidebar--categories-navigation"]', # only navi pannel
                              '//div[contains(@class,"panel--paging")]/a']), # include pagination         
        ), 
        follow=True,
        process_links='link_filtering',                    
        callback= 'parse_item'
    ),
)

添加链接过滤：

# get max amount of results per category and add n=x results to url
def link_filtering(self, links):
    for link in links:
        if re.match('.*\?.*',link.url) is None: #add all parameters if there are none
            link.url = "%s?p=1&followSearch=10000&o=1&n=1000" % link.url
        else:  # add max amount of results to pagination
            link.url = "%s&followSearch=10000&o=1&n=1000" % link.url
    return links  

抓取工具会一遍又一遍地继续抓取相同的网址。如何防止这种情况并保留添加的参数？

Answer 1

from w3lib.url import canonicalize_url

然后

link.url = canonicalize_url(link.url)

这会有帮助吗？

并保留原来的回报