Scrapy

Scrapy is the industry standard for large-scale, asynchronous web crawling in Python.

Architecture

• Spiders: Define how to navigate a site and extract data.
• Item Pipelines: Process the extracted data (clean it, save to DB).
• Middlewares: Intercept requests/responses to add headers, handle proxies, or bypass captchas.

Example Spider

python

import scrapy

class BlogSpider(scrapy.Spider):
    name = 'blogspider'
    start_urls = ['https://blog.example.com']

    def parse(self, response):
        for title in response.css('.post-title ::text').getall():
            yield {'title': title}

        for next_page in response.css('a.next-page ::attr(href)').getall():
            yield response.follow(next_page, self.parse)