Scrapy is an open-source library for web automation that enables you to build spiders to crawl and extract data from websites. It offers a set of tools for generating rules and executing them in an interactive environment, as well as a number of features to help you get started quickly and efficiently.
A powerful and asynchronous crawler with many configuration options that can be tuned to your needs. Learn how to pause and resume your crawls on large sites, adjust the rate of request and downloads dynamically based on load, or use asyncio and asyncio-powered libraries to customize how pages are requested and downloaded.
XPath support for scraping data from web pages
Using XPath to extract data is one of the core features of Scrapy. It allows you to easily and efficiently generate complex and scalable spiders that can automatically search and follow links, extract data, and save it in different formats and storages.
Concurrent Requests
The Requests package in Scrapy allows you to send requests to web pages in parallel rather than sequentially, which is a majorĀ this article speed boost over the traditional approach of sending each request one by one.
This is especially important when you are scraping a large website that requires a lot of memory and CPU resources to process the data, as it can take long for each page to be scraped in its entirety.
AutoThrottle
The AutoThrottle extension allows you to control how many concurrent requests Scrapy will send to each remote site. It can be adjusted by a user to increase the throughput and improve the load on the remote servers, while also being more polite to the website owners.
You can set the number of requests to be sent per domain and per IP by setting the options. The default value is 1.0, but you can set it to a higher value (e.g. 2.0) to maximize the throughput of the scraper on the network and improve the crawling speed on the remote server.
Several other configurable options let you customize how the crawler runs on a specific machine and on a network. This can be useful for testing and troubleshooting purposes, as it allows you to see how the crawler behaves on your hardware before deploying it in production.
Asynchronous Crawler
The asynchronous crawler in Scrapy can be configured to run in a single thread or on multiple threads, which can dramatically decrease the overall time it takes to scrape a web page. It also makes it easy to pause and resume a crawl on a large site, and asynchronously fetch images from the scraped data.
Item Adapter
The item adapter in Scrapy is a handy class that helps you populate items with the data that you scrape from the web. It supports a variety of objects for holding items such as dictionaries, attrs, data classes and more.
In a nutshell, the item adapter helps you extract data and return it in a useful format like JSON, CSV or XML. This is useful for saving the scraped data in a file for later retrieval, or storing it on a database.