We’re sure you’ve copied-pasted some text from a site you have visited in the past: did you know that this has a name? Even copying and pasting a simple text on an internet casino site is called “web scraping,” and it has been done since the advent of the internet. However, it is no longer done “manually” but on a much larger scale and almost completely automatically, thanks to specialized software. In this article, we will briefly explain what web scraping is and list some of the best open-source software you can use for it.
What Is Web Scraping?
This technique is also known as “web harvesting” and “web data extraction”. In its simplest definition, web scraping means extracting data from a website. For example, if you use the Ctrl + S shortcut while visiting a web page, a window will open asking where you want to save that page. When you do this, you save that page on your computer for offline access. Web scraping tools do just that, but they are fully automated and work on a much larger scale.
Web scraping can be done for many different purposes. With this technique, for example, you can save all phone numbers and email addresses on a site, combine weather information from different sources or save entire image files on a site. Web scraping tools only give you the opportunity to access and extract data from websites: what you do with that information is up to you. And of course, what you can do depends on the capabilities of the tool you use. So, below you’ll find a list of the best open-source web scraping tools.
This tool was created with Python and is currently the most popular option on the market. Scrappy works very fast, and it is always stable. More importantly, there are plenty of help files and step-by-step guides for beginners. You can save your downloaded data in JSON, XML and CSV formats. Since it has many plug-ins, you can add new functions without having to change the main program files. The user base is very helpful and answers all questions from beginners.
This tool was created with JAVA and its biggest advantage is that it has a web-based interface. So, you can use it from any device and anywhere, as long as you have an internet connection. Heritrix has pluggable modules, and you can achieve different functions by using them. However, perhaps the most striking feature of this tool is its “site-friendliness”: Heritrix complies with robot.txt exclusion instructions when collecting data and works in a way that does not interfere with the normal activities of the site. This is important because many web scraping tools on the market are very “rude” when collecting data, rendering the site almost inoperable.
This is one of the oldest tools on the market. Web Harvest was created with JAVA and is not a good option for beginners. It is unquestionably a powerful tool, but you need to know scripting languages to access most of its functions. Web Harvest collects data with techniques such as XSLT, XQuery and Regular Expressions, and you can give it many different capabilities by using custom JAVA libraries. Likewise, with your own scripts, you can make it do almost anything that other web scraping tools on the market cannot do. Web Harvest is a very powerful tool and is among the best, but you need to know what you’re doing to use it effectively.
This is a very interesting tool because it tries to imitate human interaction with the site while working. In other words, it doesn’t act like a “robot”. Mechanical Soup consists of a set of Python libraries, using special libraries called REQUESTS for HTTP sessions and BeautifulSoup for document navigation. It clicks on links, follows redirect commands and fills out forms, just like a real person. Although it was designed as a scraping tool, it can also be used for other purposes thanks to these abilities. It’s not very fast because of the way it works, but it can access data that would not otherwise be available and supports CSS & XPath selectors.