Design and Implementation of Web Crawler System Based on Python Technology

Extracting effective information from massive data and mining potentially valuable relationships has become a hot topic in the current research field. Web crawler has the function of automatically grasping web page information, and can automatically obtain the content of the accessed page. Through analysis, users can quickly obtain the information they need. Web crawler is an effective means to extract effective information from massive data. In view of the limitations of open web crawlers such as Laebin, Nutch and Heritrix, this paper studies web crawlers based on Python technology, including Requests, Scrapy and Selenium. The realization of three kinds of web crawler is studied, and the simulation experiment and result analysis are carried out. The results show that Scrapy technology is recommended for practical application if there is no special requirement. Because Scrapy supports asynchronous crawling, concurrency is flexible, supports crawling on different urls, and is easy to use for simple crawling tasks.