Web Scraping Tips and Tricks
Web scraping is a tried and tested way of collecting, organizing and analyzing a wide range of information on the World Wide Web in a disordered fashion. Web scraping can automatically help in retrieving information and data as well as transform it into a more significant format. (Image source: Udemy)
The best way to wriggle the internet is through proxy servers. Some of the best rotating proxy services include geosurf, netnut, oxylabs and proxy rain. The proxy serves are used to provide improved security and reliable performance. Some of the best proxy softwares include; ultrasurf, free proxy, squid and tinyproxy. They highlight various option of processing website to collect the best information possible. Web scraping can be way too hard, but this article will help you understand the process in the simplest way possible.
The following are the best tips and tricks of web and scraping:
Filter Navigation: Unless it’s necessary, do not pros or take each link. Alternatively, draft a proper crawling plan ensuring that the scraper goes through all the essential pages. The most natural way is to go after everything, however this would result into loss of time, storage as well as bandwidth.
Make a URL Table: It’s best to retain all the URL tables for links that have been crawled in a key-value store or a table. This will help in case the crawler breaks down before you finish. If you dont have this URLs list, most of your bandwidth and time will be lost. Therefore ensure the list of URLs is maintained correctly.
Local Caching: While sourcing bigger sites, it’s advisable to cache all the information and data you downloaded before. Thus, there will be no need to reload the website if the page is required again during the scraping process. Key-value is easy to store in a format such as Redis. Nevertheless, MySQL can also be used as a caching apparatus.
Crawling in phases: Scraping is safe and simple if cut in different short phases. For instance, a bigger site can be broken into two phases during scraping; one, to download the pages that help in parsing their content, and two, to accumulate the links you will require to extract information and data.
Optimizing the request: Larger sites employ a wider range of services that help in tracking the crawling process. In case you send multiple request from a common host, or IP address, this services will categorize you as a Denial of Service (DOS) attack on their site. As a result, they will instantly block you. Therefore, it is best to analyze and recheck all your requests as well as the chain perfectly. This makes them more like the human. You need to identify the typical response time of the site, then choose the number of multiple request to the website.
Always be authentic: During the scraping process, use a header with your email address and name to help the site know you. Various websites get infuriated at people who scour their information and data. Even if you are friendly, you wouldn’t want to do unlawful things. Further, you need to recognize the request header, thus ensuring you know the people tracking the logs of the server who may contact you if there is need.
Check for native API: Many websites render the API’s for programmers to help them collect all the information data required. Additionally, they provide all the necessary supporting credentials. Website with API, show that there are no crawling constraints. Therefore, all you need to do is to understand the policy and requirements of their data as well as information and data usage.
The JSON support: When a website doesn’t expose the API and you still want to scrap the information data you need to consider JSON support. Pages with a shorter load time are likely to be using JSON. Press F12 to enter the Developer Tools window. Load your webpage once again then click on ‘Sources’ to see pages ending in ‘.json’. At this point, you will see the source site. Then, open a new tab and paste the link, and JSON will be shown with the data.
In conclusion, when scraping the web, ensure that you practice all the time. Find tutorials on the internet, read widely and try writing the codes by yourself to help you solve the problem.
