Web scraping or simply scraping is the automated extraction of data from websites. In a nutshell, web scraping allows you to access content on sites that are otherwise difficult to crawl and format with conventional methods like XML feed. Web scraping lets you access data from sites that are hard to crawl or require a paid membership. Automated website content extraction saves time and money. Online scraping is important for acquiring foreign policy research data and missing or outdated data from subscription-based databases.
Web scraping involves the use of software known as a parser. The use of this software is needed because websites have complex codes that need to be interpreted so that they can be extracted. Web scraping consists of three main components: source code, parser, and HTML generator. The source code is the text that you need to extract from the page. The parser takes this source code and finds all the elements in it such as paragraph tags and then pieces together all those individual elements into one string of code. The HTML generator recreates the code that the parser first broke down, and the main difference is that it will make it easier for a human to view and understand.
Tips For Web Scraping Without Getting Blacklisted
Here are a few tips for web scrapers who are trying to avoid getting blacklisted from the websites they scrape:
1. Check the website’s terms of service
Checking the website’s terms of service is the initial stage of any scraping endeavor. The quickest method to accomplish this is to visit the website yourself, enter a few scraped data bits, and observe the results. If you discover more than a few scrapes on a site, it may be advisable to avoid it until they grant you access. The website will likely use a CAPTCHA system to prevent scrapers from entering. This website may blacklist you if you scrape huge amounts of data from it, preventing you from obtaining additional data.
2. Use a CAPTCHA solver
Captcha is an image that displays a bunch of distorted text, and you need to type it back to prove you are human. Solving Captcha is never a problem because there are a lot of websites that generate free Captcha solvers. There are Captcha-breaking tools available online that can solve various levels and types of Captchas.
Captcha includes words that are difficult for bots to interpret and solves this by asking the user to identify images of words or phrases. If you have previously scraped data from the website and are re-accessing it, then you may want to solve these CAPTs so as not to get blacklisted. The easiest way to accomplish this would be to use a bot that already solved the CAPTCHAs like the OCRbot.
3. Limit the number of requests
The use of webscraping services to obtain data is unreliable and should be supplemented with other methods of data harvesting. It is essential to realize that a website may take legal action against you if you scrape an excessive amount of data from their site. Also, many websites are concerned about robots they do not recognize because they might cause issues when extracting big volumes of data.
In the case that the website removes or modifies any scraped information, the scraper will have to repeat the process, wasting more time and money. This can lead to scrapers failing to update their information once they have extracted the necessary data. The scrapers are advised to limit the number of pages that they scrape in a single session. Websites often state their terms of use during the registration process, which include limits for data accumulation.
4. Formatting
Using appropriate formatting is essential as it helps in making data easier to parse and interpret. The scraped information you obtain should not be formatted in a way that it is hard to identify or extract from the website anyway. The way the data is stored on the website will determine the format in which you should obtain it. Most websites store data in HTML format and you should scrape it using T-SQL, as this is best for SQL-based databases. However, if you are just starting out, then HTML tables can be scraped using a number of tools.
5. Using a proxy
Proxy use speeds up webscraping. Web proxies bypass firewalls to extract data quickly. You should be warned, however, that the proxies may not remain long enough to permit scraping. Moreover, proxy servers tend to slow down the process by requiring your browser to send repeated requests before each page can load. Using a proxy prevents you from being blocked by spam prevention and Captcha systems. Also, you should utilize HTTPS connections wherever possible, as these are more harder for robots to detect than HTTP connections. If you need reliable and secure private proxies, check out https://privateproxy.me/, a trusted provider of high-quality PivateProxy for web scraping and other online activities.
6. Monitor your scraping activity
There are numerous free monitoring services that enable you to watch your webscraping operations in real time. These services provide data on which URLs have been scraped the most, allowing you to find the most popular URLs for scraping. The information on which pages have been scraped most is important to know if you need to apply up-to-date changes to your data and maintain it in a safe, new format. The data from these monitoring services can be accessed through the API. The API might also indicate the website’s response time, so you will know how fast it is for the site to identify that your request has been successful.
7. Using multiple browsers
You can protect your scrapers by using different browsers when accessing websites. For example, you may use Internet Explorer when accessing publicly available websites and Google Chrome when scraping password protected pages. The reason for this is that different browsers have different levels of compatibility with the websites’ coding. Also, a site will blacklist you if they see your browser on a large amount of pages.
8. Using multiple accounts
Using numerous accounts is another method for avoiding blacklisting. This will assist you in isolating the scraped data and preventing it from being linked to your main account. Certain websites may attempt to link your IP address and user account, thus it is essential that each account has a distinct IP address and geographic location to avoid raising red lights.
Conclusion
Webscraping is a useful tool that enables you to extract data from multiple sites very quickly. The main concerns you should have been in the use of sanitizing software, preventing excessive requests and using appropriate formatting to ensure the scraped information will not be hard for bots to extract. It is advisable that you record your progress before starting off and plan an end date for your session.