Semalt - Web Scraping Techniques You Should Know About

23.05.2018

Semalt – Web Scraping Techniques And Languages You Should Know About

Web scraping, also known as data extraction and web harvesting, is a technique used to extract data from the net.

Programmers, developers, webmasters and freelancers often need to scrape content from different web pages. A web scraper is the Application Programming Interface (API) that helps extract data from multiple sites and blogs.

General Techniques For Web Scraping: The process of web scraping is still a developing process, but it favors more practical solutions that are based on already-existing techniques and applications as compared to its ambitious counterparts. The major techniques for web scraping are discussed below.

1. Copy-and-paste: There are times when the most famous and best web scraping tools and services cannot replace the human's manual examination and copy-and-paste. Thus, copy-and-paste is the only workable solution when sites explicitly set up barriers to prevent the machine automation.

2. Text pattern matching: http://rankexperience.com/articles/article2433.html

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It is one of the best and most reliable web scraping techniques. Text pattern matching involves different programming languages such as PHP, Python, JavaScript, C++, and Ruby, and data is extracted from the websites based on the UNIX grep commands.

3. HTTP programming: It is possible to retrieve the dynamic and static websites by posting different HTTP requests and using the socket programming.

4. HTML parsing: Blogs and websites have an extensive collection of pages generated from underlying structured sources like databases. In HTML parsing, a program is used to detect HTML text from different sites. It transforms it from unstructured form to organized and readable form. HTQL and XQuery are the two major data query languages.

These are used to parse the HTML pages in a better way.

5. Semantic annotation recognizing: The web pages might embrace metadata, annotations and semantic markup, which are used to locate the particular data snippets. If an annotation is embedded in a web page, then this web scraping technique can be viewed as the special case of DOM parsing.

The Best Programming Languages For Web Scraping: With PHP, Node.js, C++, and Python, you can easily undertake multiple data scraping and web crawling tasks at a time. Plus, these languages are used to build different scraping software.

1. Node.js: This language is great at web crawling and supports distributed crawling in a better way. Node.js is not suitable for large-scale web scraping projects due to its limited options and codes.

2. C & C ++: Both C and C++ offer great performance, but the costs of developing the web scrapers with these languages are high. Thus, C and C++ are not suitable for small and medium-sized businesses.

3. PHP: PHP is one of the best web scraping languages. It is used to build crawling programs and is easy-to-learn. http://rankexperience.com/articles/article2433.html

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4. Python: It's safe to mention that Python is the most famous web scraping language. It is capable of handling different data extraction and web crawling processes conveniently and smoothly. BeautifulSoup is the Python library that has been designed for ef cient, fast and accurate web scraping tasks. Some of the most notable features are Pythonic idioms for navigation, searching, and modifying the parse trees.

http://rankexperience.com/articles/article2433.html

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