Scrapy下一页数据获取与页面跳转及多页爬取无输出排查

Hey there! Let's tackle your two Scrapy questions one by one, with practical fixes and explanations:

Handling pagination in Scrapy is straightforward, and there are two common approaches depending on your needs:

方法1：手动提取下一页链接（灵活自定义） #

This is the most flexible option, great for when you need custom logic around pagination:

• First, process the data from the current page in your parse (or custom callback) method
• Use XPath/CSS selectors to extract the next page's URL. For example, if the next page button has a class like next-page:

next_page_link = response.css('a.next-page::attr(href)').get()

• Convert relative URLs to absolute ones with response.urljoin() (critical if the link doesn't include the full domain)
• Send a new request to the next page, reusing your parse method to loop through pages:

if next_page_link:
    yield Request(url=response.urljoin(next_page_link), callback=self.parse)

方法2：用CrawlSpider自动跟进链接（简化固定规则） #

If your pagination follows a consistent pattern, CrawlSpider can automate link following:

• Import the necessary classes and define a Rule to match pagination links:

from scrapy.spiders import CrawlSpider, Rule
from scrapy.linkextractors import LinkExtractor

class SaabCrawlSpider(CrawlSpider):
    name = 'saab_crawler'
    allowed_domains = ['thesaabsite.com']
    start_urls = ['http://www.thesaabsite.com/parts_om.php']

    rules = (
        # Follow all pagination links and process each page with parse_item
        Rule(LinkExtractor(allow=r'/parts_om\.php\?page=\d+'), callback='parse_item', follow=True),
    )

    def parse_item(self, response):
        # Process data from each page here
        print("Processing page:", response.url)

Looking at your provided code, there are several clear issues causing the lack of output. Let's fix them step by step:

Issue 1: Invalid allowed_domains configuration #

allowed_domains should only contain the base domain, not a full path. Your current value ['thesaabsite.com/parts_om.php'] will block all requests because the domain doesn't match. Correct it to:

allowed_domains = ['thesaabsite.com']

Issue 2: Truncated start_urls #

Your start URL is incomplete (http://www.thesaabsite.com/parts_...), so Scrapy can't send a valid request. Replace it with the full, working URL (e.g., http://www.thesaabsite.com/parts_om.php).

Issue 3: Missing parse method #

You didn't define a parse callback. Scrapy's default parse method does nothing, so even if requests succeed, there's no code to generate output. Add a parse method to handle responses and print content.

Fixed Full Code Example #

# -*- coding: utf-8 -*-
from scrapy import Spider
from scrapy.http import Request

class SaabSpider(Spider):
    name = 'saab'
    allowed_domains = ['thesaabsite.com']
    # Use the complete, valid start URL
    start_urls = ['http://www.thesaabsite.com/parts_om.php']

    def parse(self, response):
        # Add your print logic here to confirm the spider is working
        print("Successfully fetched page:", response.url)
        print("Page title:", response.css('title::text').get())

        # Optional: Add pagination logic here (using the method from Question 1)
        # next_page = response.css('a.next-page::attr(href)').get()
        # if next_page:
        #     yield Request(url=response.urljoin(next_page), callback=self.parse)

Extra Checks if Still No Output #

• If the site blocks Scrapy via robots.txt, set ROBOTSTXT_OBEY = False in your settings.py to test
• Verify you can access the target URL from your network (or set up a proxy if needed)
• Double-check that your selectors match the actual page structure if you're extracting data later

内容的提问来源于stack exchange，提问作者Muhammad Danial