python - Pass scraped URL's from one spider to another

Question

How can I send the scraped URL's from one spider to the start_urls of another spider?

Specifically, I want to run one spider which gets a list of URL's from an XML page. After the URL's have been retrieved I want them to by used by another spider for scraping.

from scrapy.spiders import SitemapSpider

class Daily(SitemapSpider):
    name = 'daily'
    sitemap_urls = ['http://example.com/sitemap.xml']

    def parse(self, response):
        print response.url

        # How do I send these URL's to another spider instead?

        yield {
            'url': response.url
        }

Answer 1

From first spider you can save url in some DB or send to some queue (Zerro, Rabbit MQ, Redis) for example via pipeline.

Second spider can get the url with method - start_requests

class MySpider(scrapy.Spider):
    name = 'myspider'

    def start_requests(self):
        urls = my_db.orm.get('urls');
        for url in urls:
            yield scrapy.Request(url)

Or urls can be passed to spider from queue broker via cli or API. Or spider can be just launched from broker and launched spider get his url by start_requests.

Really exists many ways how you can do it. The way depend of the criteria why you need to pass urls from one spider to other.

You can check this projects: Scrapy-Cluster, Scrapy-Redis. May be its what you searching for.