python - 如何判断rss是否更新过

Question

最近在写一个python程序要把一些rss中的文章不断获取下来

但不知道怎么判断rss是否更新过，只获取那些更新出来的文章

目前的想法是对每一个rss存一个最新文章的时间，下一次把所有更新的文章获取下来，然后更新这个最新时间

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对了还有另外一个问题，就是感觉rss中的文章数没有网页上多，貌似好几天才有新的，但网页上是每天都有的，是什么原因？

Answer 1

Theoretically, RSS should return a last-modified or etag (atom) in the http header, which can be judged by this

In python’s feedparser, you can use it like this

import feedparser
d = feedparser.parse(rss_url)
d = feedparser.parse(rss_url, modified=d.modified, etag=d.etag)
d.status # 304
d.feed # {}

If there is no update, you will not get anything the second time

Answer 2

Doesn’t RSS have a GUID? Save the latest GUID and make a judgment when crawling again. Whether or not RSS has been updated is the business of other people’s server programs and you can’t control it either

Answer 3

lz, please give me this program code! The final topic is this. I would like to ask the poster for help. I have zero basic knowledge and how to complete this project quickly. Crab