python - Scrapy:收集重试消息

Question

爬虫有一个最大的返回次数，记录在案here .到达那里后，我收到了类似于以下内容的错误:

Gave up retrying <GET https:/foo/bar/123> (failed 3 times)

我相信消息是由代码 here 产生的.

但是，我想对放弃做一些总结。具体来说，我想知道是否可以:

1. 提取123 URL 的一部分(ID)并将这些 ID 写到一个单独的文件中。
2. 访问 meta原文信息request . This documentation可能会有帮助。

Answer 1

您可以子类化 scrapy.contrib.downloadermiddleware.retry.RetryMiddleware 并覆盖 _retry() 以对请求做任何您想做的事情而不是放弃。

from scrapy.contrib.downloadermiddleware.retry import RetryMiddleware
from scrapy import log

class CustomRetryMiddleware(RetryMiddleware):

    def _retry(self, request, reason, spider):
        retries = request.meta.get('retry_times', 0) + 1

        if retries <= self.max_retry_times:
            log.msg(format="Retrying %(request)s (failed %(retries)d times): %(reason)s",
                    level=log.DEBUG, spider=spider, request=request, retries=retries, reason=reason)
            retryreq = request.copy()
            retryreq.meta['retry_times'] = retries
            retryreq.dont_filter = True
            retryreq.priority = request.priority + self.priority_adjust
            return retryreq
        else:
            # do something with the request: inspect request.meta, look at request.url...
            log.msg(format="Gave up retrying %(request)s (failed %(retries)d times): %(reason)s",
                    level=log.DEBUG, spider=spider, request=request, retries=retries, reason=reason)

然后就是在您的 settings.py

中引用这个自定义中间件组件了

DOWNLOADER_MIDDLEWARES = {
    'scrapy.contrib.downloadermiddleware.retry.RetryMiddleware': None,
    'myproject.middlewares.CustomRetryMiddleware': 500,
}