Shulou(Shulou.com)06/02 Report--

This article will explain in detail how to use crawlers to collect information. The editor thinks it is very practical, so I share it for you as a reference. I hope you can get something after reading this article.

1. The stand-alone crawler mainly spends its time waiting for the response of the network request to reduce the visit to the website as much as possible.

This can not only reduce their own workload, but also reduce the pressure on the website, but also reduce the risk of capping. First of all, the process should be optimized to make the process as simple as possible to avoid repeated extraction in multiple pages. Then go heavy, generally according to the only judgment of url or id, those who have climbed will no longer continue to climb.

2. Distributed crawlers, distribution is not the essence of crawlers, nor is it necessary, for tasks that are independent of each other and have no communication.

Even if all the methods are used up, the number of web pages that a machine can crawl per unit time is still limited, and it still takes a long time to calculate in the face of a large number of web page queues. In this case, you have to exchange time with the machine, which is the distributed crawler. Distribution is not the essence of crawlers, nor is it necessary. For tasks that are independent of each other and do not communicate with each other, tasks can be divided by hand and then executed on multiple machines separately, reducing the workload of each machine, and the time required will be greatly reduced. The above two methods can improve the collection efficiency of the crawler and hope to be helpful to you. In addition, we should also pay attention to the anti-crawling mechanism of the target site in the collection process.

This is the end of the article on "how to collect information with reptiles". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, please share it for more people to see.

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