Parsing sites

Parsing data from a site is a procedure for collecting information according to specified parameters. The site parser program parses the specified online resource and provides information in the specified form. You can parse a site using a wide variety of parsers – multithreaded and universal, as well as highly specialized, focused on specific tasks. Site parsers work a bit like the search bots used by well-known search engines. However, they usually parse sites according to given parameters and collect the content itself with the possibility of using it, and not just provide information about it.

A content parser from a site can collect it from any sources on the network open to people and search bots. These can be catalogs, Internet forums, classifieds sites, shops, business card sites, blogs, corporate portals, marketplaces and much more. For example, the owners of online stores actively use site parsers to automate the procedure for collecting characteristics and photos of products posted on the official websites of manufacturers and distributors. That is, they automate work that would take a person dozens of times longer and would require significantly more funds.

The same applies, for example, to real estate agents. For them, a program for scraping ad sites, developers and other sources of data on new and secondary real estate becomes a source of valuable information for business. Organizers of joint purchases also use parsing of data from the sites of manufacturers and large suppliers. For them, there are entire platforms with which it is easy to integrate a site parser to automatically fill such a platform with content.

Parsing data from the website of a news agency will allow you to add a news feed to your resource, parsing a website with currency rates – a plugin with main rates. A search engine optimization specialist with the help of a site parser collects an array of key queries by which his competitors are most often found – this is the basis of promotion in search engines.

Anyone can view the source code of any page manually, but getting any content will take a long time. A universal site parser will be able to read the code of any page in a split second, as it is focused on this. At the same time, he compares the information received with the specified search criteria – some of which, for example, may be completely hidden from the regular visitor of the site. This is followed by the extraction and analysis of data, as well as their saving in the required format – it can be an html document or even a plain text format.

A website parser for keywords is used for a variety of tasks. This is the automation of orders and purchases, scanning stores in search of rare goods, sending messages about discounts in automatic mode. All this makes web scraping services very popular.

A universal site parser is a script or program that is used to load pages in html format and extract data from it. For this, a number of elements are provided in the parser. In particular, it is a web crawler that crawls through the pages of a target resource and sends HTTP requests to specific addresses, following the logic and structure of this resource. The module transfers the received data to the next component of the parser – the extractor.

An extractor, or extraction module, processes HTML and extracts data from it in a semi-structured form. Various methods are used for this. For example, regular expressions, which are used for pattern searches when processing text. Using this method, the most routine tasks of parsing sites are solved, for example, it allows you to get all the email addresses from the desired page, since they all have a similar format. Moreover, it will also extract addresses that are not visible to the human user.

The most commonly used method of parsing is HTML, which is converted by the parser into a tree-like structure with the ability to navigate through it using special query languages. In addition, analysis using DOM selectors such as XPath, as well as analysis with extraction using artificial intelligence, is applied. The latter model is used relatively rarely, it is based on the use of machine learning models for parsing sites. AVADA MEDIA has specialists who develop parsers using machine learning methods for specific tasks.

Also, in a typical site parser, there are two more modules: data transformation and cleaning and a data serialization and persistence module. The first is responsible for converting the received information into a format suitable for saving. The second allows you to get data in a format suitable for storing in databases.

If you need to solve one of the following tasks:

• collection of information in the categories of interest of the site with transformation for uploading to your resource;
• collection of keywords for specified sites;
• getting all ads of a specific topic on ad sites;
• analysis of competitors or any other task solved by parsing sites

– You can order the development of a parser at AVADA MEDIA. We implement the most complex turnkey projects in accordance with customer requirements.