Skip to main content

What Is A Web Crawler?

 

A web crawler is an internet bot that indexes the content of websites. It can automatically extract target information and data from websites and export data into structured formats (list/table/database).


Have you ever wondered how search engines like Google, fetch data from different parts of the web and serve it to you as a user, based on your query? The method used by applications like this is termed crawling.


Search engines work and by crawling and indexing billions of web pages using different web crawlers called web spiders or search engine bots. What these web spiders do is follow links from each web page that have been indexed to discover new ages.


Is it legal to crawl a website?


So is it legal or illegal? Web scraping and crawling aren't illegal by themselves. After all, you could scrape or crawl your own website, without a hitch. Startups love it because it's a cheap and powerful way to gather data without the need for partnerships.


Step by step to build a web crawler:

- Find websites you want to scrape

- Find the selectors to choose the content to extract

- Tabulate the list of sites and their respected selector into a simple list for easy reference

- Write a simple web scraper program using Python or Node.js

- Run the scraper with the help of a cron or a scheduler

- Use the extracted content to create a Digestible Content  










Comments

Popular posts from this blog

What is Micro Frontends Part -1

The term Micro Frontends first came up in ThoughtWorks Technology Radar at the end of 2016. It extends the concepts of micro services to the frontend world. The current trend is to build a feature-rich and powerful browser application, aka single page app, which sits on top of a micro service architecture. Over time the frontend layer, often developed by a separate team, grows and gets more difficult to maintain. That’s what we call a Frontend Monolith . The idea behind Micro Frontends is to think about a website or web app as a composition of features which are owned by independent teams. Each team has a distinct area of business or mission it cares about and specialises in. A team is cross functional and develops its features end-to-end, from database to user interface. Monolithic Frontends Organisation in Verticals Top resources for you to learn more about Micro frontends: Server-side rendering micro-frontends – the architecture . : This blog series explores how to implement micro...

Things to consider when adopting Cloud Computing

    If you are someone who is new cloud computing and is deciding to adopt cloud computing, there are several factors you have to consider. Define the role of Cloud :  Are you looking to host your website or a mobile app or you just require storage space for your files.  Business flows and Priorities of the Solution :  At what point, does your cloud solution fit in. Do I already have a system which I need to upgrade. Find the priorities of the system of your business. Need for Integrations with Internal and External systems :  Based on your application needs, we need to figure out the Internal and External services that is essential part or something you cannot replace with your new cloud solution. Once we identify these sub systems and find a possible way to work with your Cloud Framework. Financials of running the solution:  Running a cloud deployment can be cost effective or a costly affair, based on how it is setup. Different services have differen...

CORS - Cross-origin resource sharing

By Nicho Antony Today, there are many applications that depend on APIs to access different resources. Some of the popular APIs include weather, time, and fonts.  There are also servers that host these APIs and ensure that information is delivered to websites and other end points. Therefore, making cross-origin calls, is a popular use case for the modern web application.  Let’s say accessing images, videos, iframes, or scripts from another server. This means that the website is accessing resources from a different origin or domain. When building an application to serve up these resources with Express, a request to such external origins may fail. This is where CORS comes in to handle cross-origin requests.  What is CORS?   CORS stands for Cross-Origin Resource Sharing. It allows us to relax the security applied to an API. This is done by bypassing the Access-Control-Allow-Origin headers, which specify which origins can access the API.  In other words, CORS is a br...