How do I merge results from target page to current page in scrapy?

An example from scrapy documntation

def parse_page1(self, response):
    item = MyItem()
    item['main_url'] = response.url
    request = scrapy.Request("http://www.example.com/some_page.html",
                         callback=self.parse_page2)
    request.meta['item'] = item
    return request

def parse_page2(self, response):
    item = response.meta['item']
    item['other_url'] = response.url
    return item

Partially fill your item on the first page, and the put it in your request's meta. When the callback for the next page is called, it can take the partially filled request, put more data into it, and then return it.

More information on passing the meta data and request objects is specifically described in this part of the documentation:

http://readthedocs.org/docs/scrapy/en/latest/topics/request-response.html#passing-additional-data-to-callback-functions

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