python - selenium with scrapy for dynamic page

Question

I'm trying to scrape product information from a webpage, using scrapy. My to-be-scraped webpage looks like this:

• starts with a product_list page with 10 products
• a click on "next" button loads the next 10 products (url doesn't change between the two pages)
• i use LinkExtractor to follow each product link into the product page, and get all the information I need

I tried to replicate the next-button-ajax-call but can't get working, so I'm giving selenium a try. I can run selenium's webdriver in a separate script, but I don't know how to integrate with scrapy. Where shall I put the selenium part in my scrapy spider?

My spider is pretty standard, like the following:

class ProductSpider(CrawlSpider):
    name = "product_spider"
    allowed_domains = ['example.com']
    start_urls = ['http://example.com/shanghai']
    rules = [
        Rule(SgmlLinkExtractor(restrict_xpaths='//div[@id="productList"]//dl[@class="t2"]//dt'), callback='parse_product'),
        ]

    def parse_product(self, response):
        self.log("parsing product %s" %response.url, level=INFO)
        hxs = HtmlXPathSelector(response)
        # actual data follows

Any idea is appreciated. Thank you!

Answer 1

It really depends on how do you need to scrape the site and how and what data do you want to get.

Here's an example how you can follow pagination on ebay using Scrapy+Selenium:

import scrapy
from selenium import webdriver

class ProductSpider(scrapy.Spider):
    name = "product_spider"
    allowed_domains = ['ebay.com']
    start_urls = ['http://www.ebay.com/sch/i.html?_odkw=books&_osacat=0&_trksid=p2045573.m570.l1313.TR0.TRC0.Xpython&_nkw=python&_sacat=0&_from=R40']

    def __init__(self):
        self.driver = webdriver.Firefox()

    def parse(self, response):
        self.driver.get(response.url)

        while True:
            next = self.driver.find_element_by_xpath('//td[@class="pagn-next"]/a')

            try:
                next.click()

                # get the data and write it to scrapy items
            except:
                break

        self.driver.close()

Here are some examples of "selenium spiders":

• Executing Javascript Submit form functions using scrapy in python
• https://gist.github.com/cheekybastard/4944914
• https://gist.github.com/irfani/1045108
• http://snipplr.com/view/66998/

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There is also an alternative to having to use Selenium with Scrapy. In some cases, using ScrapyJS middleware is enough to handle the dynamic parts of a page. Sample real-world usage:

• Scraping dynamic content using python-Scrapy