Introduction To Web Scraping From Semalt
Web scraping is a technique of targeted automated extraction of relevant content from external websites. However, this process is not only automated but also a manual one. The preference is on the computerized method because it is much faster, much efficient and less prone to human errors when compared to the manual approach.
This approach is significant because it enables a user to acquire a non-tabular or poorly structured data, and then convert the same raw data from an external website into a well-structured and usable format. Examples of such formats include spreadsheets, .csv files, etc.
In fact, scraping offers more opportunities than just getting data from external websites. It can be used to help a user to archive any form of data and then track any changes made on the data online. For instance, marketing firms often scrape contact information from email addresses to compile there marketing databases. Online stores scrape prices and customer data from competitor websites and utilize them to adjust their prices.
Web Scraping in Journalism
- Collection of report archives from numerous web pages;
- Scraping data from real estate websites to track trends in the real estate markets;
- Collecting information pertaining membership and activity of online firms;
- Gathering comments from online articles;
Behind the web's facade
The core reason why web scraping exists is that the web is mostly designed to be used by humans and often, these websites are designed only to display structured content. The structured content is stored in databases on a web server. This is why computers tend to provide content in a manner that loads very quickly. However, the content becomes unstructured when users add to it such boilerplate materials as headers and templates. Web scraping involves using particular patterns that can enable a computer to identify and extract the relevant content. It also instructs the computer how to navigate through this or that site.
It is essential that before scraping, a user checks whether the site content provided accurately or not. Furthermore, the content should be in a state where it can be easily copied and pasted from a website to Google Sheets or Excel.
In addition to that, it is vital to ensure that the website provides an API for purposes of extracting structured data. This will make the process a bit efficient. Such APIs include Twitter APIs, Facebook APIs and YouTube comments APIs.
Scraping techniques and tools
Over the years, a number of tools have been developed, and now they are vital in the process of data scraping. As time goes by, these tools and techniques are differentiated so that each of them has a different level of effectiveness and capabilities.