What is web scraping?
The concept of big data cannot exist without web scraping. In fact, web scraping is the process of gathering data for the big data technology. In a simple form, web scraping is the process of extracting data from websites for another purpose. A scraper is a tool, program, robot, or piece of code that sends a GET query to a target web page and it parses an HTML document depending on the instruction it received. The tool now searches for the required data within the document. It extracts and converts it into the required format and it also saves the scraped data into a specified location.
Information is power and you can only remain ahead of your competitors if you have access to more information than them. This is why you need to know how to use a scraper. The data to be extracted can be text, videos, images, product items, contact information like phone numbers and emails.
What you can use for web scraping?
You can use third party web scraping services through a web interface or an API. Examples of such services are DiffBot and Embedly, just to mention a few.
You can also try any of the various open source programs created with the different programming languages like Goutte written in PHP, Morph & Readability written in Ruby, Goose & Scrapy written in Python…etc.
You could also develop your own data extraction tool with any of the libraries available. One of them is Nokogiri library that can be used to develop a web scraper with the codes written in Ruby language.
Some of the challenges involved in data scraping
Virtually all websites have a unique layout so it is difficult to use the same configuration and sitemap for more than one website. Developers sometimes make mistakes while coding their scraper and this makes reading difficult for scrapers.
Many websites are built with HTML 5 which makes every element unique.
• Some websites change their layout several times in a year and once the layout is changed, you will need to reconfigure your scraper and it is a little difficult to keep track of these changes.
• Availability of too many comments, ads and navigation elements make a website difficult to scrape. • Presence of links to the same image presented in different sizes can make scraping difficult to carry out.
• The content of some websites are not written in english.
How to work around the challenges
If you intend to extract data from a few websites, it is better to develop your own scraping tool and you will need to customize it for every website. That way, you will get a high quality output. Conversely, if you intend to deal with a large number of websites, you should adopt a more sophisticated approach like hiring a third party data extraction company.
An illustration of data extraction
Here is an illustration of how data extraction works and the system used in this illustration is called the Duck System. The system takes the URL of the site to be scraped as its input. The system sends it to the most appropriate reader based on the scraping instruction and the kind of data to be scraped. If the task does not require any sophisticated reader, the system sends it to the default reader.
If the default reader fails to read through the URL, the system passes it to another reader. After that, the system goes to the target site to scrape the required data and outputs the scraped data. It is advisable to include a feedback support in your web scraping system so that you will be notified of any low quality content. However, this will increase the processing time and server resources for the task and it may also increase your cost if you are using third party scraping services.
When you opt for a customized scraper for a few websites, you will enjoy high processing speed. However, there will be some limitations like upload file size and capped bandwidth. These limitations have been taken care of with the asynchronous download of media and main content in the background. With that, you can enjoy high-speed data extraction with 100% quality content.
7 efficient applications for data extraction
There are so many reasons for scraping text from web pages but some of the commonest ones are for customer data collection, pricing analysis, website overhauls, competitive analysis, and collection of email addresses. As important as web scraping is, you can’t carry it out manually when you need to extract data from hundreds of web pages on a daily basis. This is why several web data scraping applications have been developed by mobile app development companies. Here are 7 of them:
1. Iconico HTML Text Extractor
While organizations regularly scrape text from competitors’ websites, they also make conscious efforts to prevent others from scraping their own sites. Some of the steps they take to prevent scraping of their sites are disabling the right click function on their site so you won’t be able to copy and paste. Some other organizations also disable view source function while some lock down their pages completely.
This is where Iconico extractor comes in. None of the technical barriers mentioned above can prevent the tool from copying HTML text from any website. It is not only efficient, it is also easy to use. You only need to highlight and copy the required text. Top web development companies that developed it updates it regularly.
This tool has several automation functions and one of them is for web scraping. UiPath also has a screen scraping function too. With both features, you can scrape table data, images, text, and other kinds of data elements from any web page. This application was developed by one of the best mobile app development companies in India.
This tool can scrape images, files, text, and it can also scrape data from PDF files. In addition, it can export scraped data to JSON, CSV files, or XML files. This is a very popular application because its developer is also a very popular mobile app development company.
4. HTML to Text
This application was developed a mobile app development company to extract text from HTML source codes of web pages. You only need to provide the URL of the page you want to scrape.
What distinguishes this tool is its point and click user interface. The interface makes it easy for users without any programming knowledge to use. Another feature of Octoparse is its ability to scrape data from dynamic web pages. It has both free and paid versions so you can try out the free version to have a feel of it. The mobile app development company that owns this application developed it for users that have little or no technical knowledge.
This is a free and open source tool. The only problem with this tool is that it requires some programming knowledge. However, its efficiency is a big tradeoff. If you can take the time to learning some programming, you will enjoy the tool. It is being used by major brands. Since it is an open source tool, it has communities of users that will help you out when you run into any challenge.
This is also a free tool and it can be used to scrape unstructured content from web pages. It will export it in a structured format. It can be scheduled to gather data from some specified web pages periodically. Kimono creates an API for your workflow so you won’t need to reinvent the wheel each time you want to use it.
In conclusion, no matter the kind of data you need to scrape, one of these tools can be of help. Just try them out and select the one that works best for you.