What Are The Different Types Of Web Scraping Approaches?
Tags: web, webdev
Published: 2022-03-04 05:59:36

The importance of Web scraping is increasing day by day as the world is depending more and more on data and it will increase more in the coming future. And web applications like **Newsdata.io** [news API](newsdata.io) that is working on Web scraping fundamentals. More and more web data applications are being created to satisfy the data-hungry infrastructures.

## Why Web Scraping is Popular?

Web scraping offers something extremely valuable that no other method can provide: structured web data from any public website.
The true power of data web scraping lies in its ability to build and power some of the world’s most revolutionary business applications, rather than simply being a modern convenience.
 
‘Transformative’ doesn’t even begin to describe how some businesses use web scraped data to improve their operations, from executive decisions to individual customer service experiences.

## What is web scraping?

Web scraping is an automated method of obtaining large amounts of data from websites. Most of this data is unstructured data in HTML format, which is then converted into structured data in a spreadsheet or database so that it can be used in various applications. there are many ways to perform web scraping to get data from websites.

These include using online services, special APIs, or even creating code for web scraping from scratch. Many large websites, such as Google, Twitter, Facebook, StackOverflow, etc. have APIs that allow you to access your data in a structured format.

This is the best option, but there are other sites that do not allow users to access large amounts of data in a structured form or are simply not technologically advanced. In this situation, it is best to use tape scraping to scrape the website for the data.

This is the best option, but there are other sites that do not allow users to access large amounts of data in a structured format or are simply not technologically advanced enough. In that case, it’s best to scrape the website for data using Web Scraping.

Web scraping necessitates the use of two components: the crawler and the scraper. The crawler is an artificial intelligence algorithm that searches the web for specific data by following links across the internet.

A scraper, on the other hand, is a tool designed to extract data from a website. The scraper’s design can vary greatly depending on the complexity and scope of the project in order to extract data quickly and accurately.

## How does web scraping work?

Web scrapers can extract all of the data on a specific site or the data that a user desires. Ideally, you should specify the data you want so that the web scraper extracts only that data quickly.

For example, you may want to scrape an Amazon page for the different types of juicers available, but you may only want information about the models of different juicers and not customer reviews.

When a web scraper needs to scrape a site, the URLs are provided first. The scraper then loads all of the HTML code for those sites, and a more advanced scraper may even extract all of the CSS and Javascript elements.

The scraper then extracts the necessary data from the HTML code and outputs it in the format specified by the user. The data is typically saved in the form of an Excel spreadsheet or a CSV file, but it can also be saved in other formats, such as a JSON file.

## What is Data Scraping Good for?

Web data extraction, also known as data scraping, has numerous applications. A data scraping tool can help you automate the process of quickly and accurately extracting information from other websites. It can also ensure that the extracted data is neatly organized, making it easier to analyze and use in other projects.

Web data scraping is widely used in the world of e-commerce for competitor price monitoring. It’s the only practical way for brands to compare the pricing of their competitors’ goods and services, allowing them to fine-tune their own pricing strategies and stay ahead of the competition.

It’s also used by manufacturers to ensure retailers follow pricing guidelines for their products. Web data extraction is used by market research organizations and analysts to gauge consumer sentiment by tracking online product reviews, news articles, and feedback.

In the financial world, there are numerous applications for data extraction. Data scraping tools are used to extract information from news stories, which are then used to guide investment strategies.

Similarly, researchers and analysts rely on data extraction to assess a company’s financial health. To design new products and policies for their customers, insurance and financial services companies can mine a rich seam of alternative data scraped from the web.

The list of web data extraction applications does not stop there. Data scraping tools are widely used in news and reputation monitoring, journalism, SEO monitoring, competitor analysis, data-driven marketing and lead generation, risk management, real estate, academic research, and a variety of other applications.

## What can I use instead of a scraping tool?

To obtain information from websites like news websites, you’ll need some kind of automated web scraping tool or data extraction software like Newsdata.io news API for all but the smallest projects.

In theory, you could manually copy and paste data from individual web pages into a spreadsheet or another document. However, if you’re trying to extract information from hundreds or thousands of pages, you’ll find this tedious, time-consuming, and error-prone.

A web scraping tool automates the process by efficiently extracting the web data you require and formatting it in some sort of neatly organized structure for storage and further processing.

Another option is to purchase the data you require from a data services provider, who will extract it on your behalf. This would be useful for large projects with tens of thousands of web pages.

## Web Scraping Techniques

The most common techniques used for Web Scraping are

- Human copy-and-paste.
- Text pattern matching.
- HTTP programming.
- HTML parsing.
- DOM parsing.
- Vertical aggregation.
- Semantic annotation recognizing.
- Computer vision web-page analysis.

**Human Copy-and-Paste**

Manually copying and pasting data from a web page into a text file or spreadsheet is the most basic form of web scraping. Even the best web-scraping technology cannot always replace a human’s manual examination and copy-and-paste, and this may be the only viable option when the websites for scraping explicitly prohibit machine automation.

**Text Pattern Matching**

The UNIX grep command or regular expression-matching facilities of programming languages can be used to extract information from web pages in a simple yet powerful way (for instance Perl or Python).
HTTP Programming

Static and dynamic web pages can be retrieved by using socket programming to send HTTP requests to a remote web server.

**HTML Parsing**

Many websites contain large collections of pages that are dynamically generated from an underlying structured source, such as a database. A common script or template is typically used to encode data from the same category into similar pages. A wrapper is a program in data mining that detects such templates in a specific information source, extracts its content, and converts it to a relational form.

Wrapper generation algorithms assume that the input pages of a wrapper induction system follow a common template and can be identified using a URL common scheme. [2] Furthermore, semi-structured data query languages such as XQuery and HTQL can be used to parse HTML pages as well as retrieve and transform page content.

**DOM Parsing**

More information: Object Model for Documents, Programs can retrieve dynamic content generated by client-side scripts by embedding a full-fledged web browser, such as Internet Explorer or the Mozilla browser control. These browser controls also parse web pages into a DOM tree, which programs can use to retrieve portions of the pages. The resulting DOM tree can be parsed using languages such as Xpath.

**Vertical Aggregation**

Several companies have created vertically specific harvesting platforms. These platforms generate and monitor a plethora of “bots” for specific verticals with no “man in the loop” (direct human involvement) and no work related to a specific target site. The preparation entails creating a knowledge base for the entire vertical, after which the platform will create the bots automatically.

The robustness of the platform is measured by the quality of the information it retrieves (typically the number of fields) and its scalability (how quickly it can scale up to hundreds or thousands of sites). This scalability is primarily used to target the Long Tail of sites that common aggregators find too difficult or time-consuming to harvest content from.

**Semantic Annotation Recognizing**

The scraped pages may include metadata, semantic markups, and annotations that can be used to locate specific data snippets. This technique can be viewed as a subset of DOM parsing if the annotations are embedded in the pages, as Microformat does. In another case, the annotations are stored and managed separately from the web pages, so scrapers can retrieve data schema and instructions from this layer before scraping the pages.

**Computer Vision Web-Page Analysis**

There are efforts using machine learning and computer vision to identify and extract information from web pages by visually interpreting pages as a human would.

## Reference

1. https://apige.medium.com/web-scraping-techniques-5030fbf1fba
2. https://rajat-testprepkart.medium.com/top-5-web-scraping-tools-you-should-know-in-2022-a67f16f8d1b8
3. https://newsdata.io/