Javascript Webscraper

Getting Started with Web Scraping in JavaScript – Geekflare

Web scraping is one of the most interesting things in the coding world.
What is web scraping?
Why is it even exist?
Let’s find out the answers.
What is Web Scraping?
Web scraping is an automated task to extract data from websites.
There are many applications of web scraping. Extracting the prices of products and comparing them with different e-Commerce platforms. Getting a daily quote from the web. Building your own search engine like Google, Yahoo, etc.., The list goes on.
You can do more than you think with web scraping. Once you get to know how to extract the data from websites, then you can do whatever you want with the data.
The program which extracts the data from websites is called a web scraper. You are going to learn to write web scrapers in JavaScript.
There are mainly two parts to web scraping.
Getting the data using request libraries and a headless browser.
Parsing the data to extract the exact information that we want from the data.
Without further ado let’s get started.
Project Setup
I assume you have Node installed, if not check out the NodeJS installation guide.
We are going to use the packages node-fetch and cheerio for web scraping in JavaScript. Let’s set up the project with the npm to work with a third-party package.
Let’s quickly see the steps to complete our setup.
Create a directory called web_scraping and navigate to it.
Run the command npm init to initialize the project.
Answer all the questions based on your preference.
Now, install the packages using the command
npm install node-fetch cheerio
Let’s see the glimpses of the installed packages.
node-fetch
The package node-fetch brings the to the node js environment. It helps to make the HTTP requests and get the raw data.
cheerio
The package cheerio is used to parse and extract the information that is necessary from the raw data.
Two packages node-fetch and cheerio are good enough for web scraping in JavaScript. We are not going to see every method that the packages are providing. We will see the flow of web scraping and the most useful methods in that flow.
You will learn web scraping by doing it. So, let’s get to the work.
Scraping Cricket World Cup List
Here in this section, we are going to do actual web scraping.
What are we extracting?
By the title of the section, I think you would easily guess it. Yeah, whatever you are thinking is correct. Let’s extract all cricket world cup winners and runner-ups till now.
Create a file called in the project.
We will be using the Wikipedia Cricket World Cup page to get the desired information.
First, get the raw data using the node-fetch package.
Below code gets the raw data of the above Wikipedia page.
const fetch = require(“node-fetch”);
// function to get the raw data
const getRawData = (URL) => {
return fetch(URL)
((response) => ())
((data) => {
return data;});};
// URL for data
const URL = “;
// start of the program
const getCricketWorldCupsList = async () => {
const cricketWorldCupRawData = await getRawData(URL);
(cricketWorldCupRawData);};
// invoking the main function
getCricketWorldCupsList();
We got the raw data from the URL. Now, it’s time to extract the information that we need from the raw data. Let’s use the package cheerio to extract the data.
Extracting data that involves HTML tags with cheerio is a cakewalk. Before getting into the actual data, let’s see some sample data parsing using cheerio.
Parse the HTML data using the method.
const parsedSampleData = (
`

I’m title

`);
We have parsed the above HTML code. How to extract the p tag content from it? It’s the same as the selectors in JavaScript DOM manipulation.
(parsedSampleData(“#title”)());
You can select the tags as you want. You can check out different methods from the cheerio official website.
Now, it’s time to extract the world cup list. To extract the information, we need to know the HTML tags that information lies on the page. Go to the cricket world cup Wikipedia page and inspect the page to get HTML tags information.
Here is the complete code.
const cheerio = require(“cheerio”);
// parsing the data
const parsedCricketWorldCupData = (cricketWorldCupRawData);
// extracting the table data
const worldCupsDataTable = parsedCricketWorldCupData(“table”)[0]. children[1]. children;
(“Year — Winner — Runner”);
rEach((row) => {
// extracting `td` tags
if ( === “tr”) {
let year = null,
winner = null,
runner = null;
const columns = ((column) => === “td”);
// extracting year
const yearColumn = columns[0];
if (yearColumn) {
year = ildren[0];
if (year) {
year = ildren[0];}}
// extracting winner
const winnerColumn = columns[3];
if (winnerColumn) {
winner = ildren[1];
if (winner) {
winner = ildren[0];}}
// extracting runner
const runnerColumn = columns[5];
if (runnerColumn) {
runner = ildren[1];
if (runner) {
runner = ildren[0];}}
if (year && winner && runner) {
(`${year} — ${winner} — ${runner}`);}}});};
And, here is the scraped data.
Year — Winner — Runner
1975 — West Indies — Australia
1979 — West Indies — England
1983 — India — West Indies
1987 — Australia — England
1992 — Pakistan — England
1996 — Sri Lanka — Australia
1999 — Australia — Pakistan
2003 — Australia — India
2007 — Australia — Sri Lanka
2011 — India — Sri Lanka
2015 — Australia — New Zealand
2019 — England — New Zealand
Cool , is int’ it?
Scraping Template
Getting the raw data from the URL is common in every web scraping project. The only part that changes is extracting the data as per the requirement. You can try the below code as a template.
const fs = require(“fs”);
const scrapeData = async () => {
const rawData = await getRawData(URL);
const parsedData = (rawData);
(parsedData);
// write code to extract the data
// here
//…
//… };
scrapeData();
Conclusion
You have learned how to scrape a webpage. Now, it’s your turn to practice coding.
I would also suggest checking out popular web scraping frameworks to explore and cloud-based web-scraping solutions.
Happy Coding
Web Scraping Using Node JS in JavaScript - Analytics Vidhya

Web Scraping Using Node JS in JavaScript – Analytics Vidhya

This article was published as a part of the Data Science Blogathon.
to f
INTRODUCTION
Gathering information across the web is web scraping, also known as Web Data Extraction & Web Harvesting. Nowadays data is like oxygen for startups & freelancers who want to start a business or a project in any domain. Suppose you want to find the price of a product on an eCommerce website. It’s easy to find but now let’s say you have to do this exercise for thousands of products across multiple eCommerce websites. Doing it manually; not a good option at all.
Get to know the Tool
JavaScript is a popular programming language and it runs in any web browser.
Node JS is an interpreter and provides an environment for JavaScript with some specific useful libraries.
In short, Node JS adds several functionality & features to JavaScript in terms of libraries & make it more powerful.
Hands-On-Session
Let’s get to understand web scraping using Node JS with an example. Suppose you want to analyze the price fluctuations of some products on an eCommerce website. Now, you have to list out all the possible factors of the cause & cross-check it with each product. Similarly, when you want to scrape data, then you have to list out parent HTML tags & check respective child HTML tag to extract the data by repeating this activity.
Steps Required for Web Scraping
Creating the file
Install & Call the required libraries
Select the Website & Data needed to Scrape
Set the URL & Check the Response Code
Inspect & Find the Proper HTML tags
Include the HTML tags in our Code
Cross-check the Scraped Data
I’m using Visual Studio to run this task.
Step 1- Creating the file
To create a file, I need to run npm init and give a few details as needed in the below screenshot.
Create
Step 2- Install & Call the required libraries
Need to run the below codes to install these libraries.
Install Libraries
Once the libraries are properly installed then you will see these messages are getting displayed.
logs after packages get installed
Call the required libraries:
Call the library
Step 3- Select the Website & Data needed to Scrape.
I picked this website “ and want to scrape data of gold rates along with dates.
Data we want to scrape
Step 4- Set the URL & Check the Response Code
Node JS code looks like this to pass the URL & check the response code.
Passing URL & Getting Response Code
Step 5- Inspect & Find the Proper HTML tags
It’s quite easy to find the proper HTML tags in which your data is present.
To see the HTML tags; right-click and select the inspect option.
Inspecting the HTML Tags
Select proper HTML Tags:-
If you noticed there are three columns in our table, so our HTML tag for table row would be “HeaderRow” & all the column names are present with tag “th” (Table Header).
And for each table row (“tr”) our data resides in “DataRow” HTML tag
Now, I need to get all HTML tags to reside under “HeaderRow” & need to find all the “th” HTML tags & finally iterate through “DataRow” HTML tag to get all the data within it.
Step 6- Include the HTML tags in our Code
After including the HTML tags, our code will be:-
Code Snippet
Step 7- Cross-check the Scraped Data
Print the Data, so the code for this is like:-
Our Scraped Data
If you go to a more granular level of HTML Tags & iterate them accordingly, you will get more precise data.
That’s all about web scraping & how to get rare quality data like gold.
Conclusion
I tried to explain Web Scraping using Node JS in a precise way. Hopefully, this will help you.
Find full code on
Vgyaan’s–GithubRepo
If you have any questions about the code or web scraping in general, reach out to me on
Vgyaan’s–Linkedin
We will meet again with something new.
Till then,
Happy Coding..!
How do you run JavaScript script through the Terminal?

How do you run JavaScript script through the Terminal?

You can Run your JavaScript File from your Terminal only if you have installed NodeJs runtime. If you have Installed it then Simply open the terminal and type “node ”. If you don’t have NodeJs runtime environment then go to NodeJs Runtime Environment Download and Download it. Example 1: Create a JavaScript File Name this file as add(a, b) {return a+b}(add(4, 6))Output:10Steps:Open Terminal or Command Path to where File is Located (using cd) “node ” and Click EnterExamples 2: Create a JavaScript File Name this file as sub(a, b) {return a-b}(sub(6, 2))Output:4JavaScript is best known for web page development but it is also used in a variety of non-browser environments. You can learn JavaScript from the ground up by following this JavaScript Tutorial and JavaScript geek! The constant emerging technologies in the world of web development always keeps the excitement for this subject through the roof. But before you tackle the big projects, we suggest you start by learning the basics. Kickstart your web development journey by learning JS concepts with our JavaScript Course. Now at it’s lowest price ever!

Frequently Asked Questions about javascript webscraper

Can JavaScript do web scraping?

js, JavaScript is a great language to use for a web scraper: not only is Node fast, but you’ll likely end up using a lot of the same methods you’re used to from querying the DOM with front-end JavaScript.

What is a JavaScript scraper?

Web scraping is an automated task to extract data from websites. … You are going to learn to write web scrapers in JavaScript. There are mainly two parts to web scraping. Getting the data using request libraries and a headless browser. Parsing the data to extract the exact information that we want from the data.Apr 4, 2021

How do you use web scraping in JavaScript?

Steps Required for Web ScrapingCreating the package.json file.Install & Call the required libraries.Select the Website & Data needed to Scrape.Set the URL & Check the Response Code.Inspect & Find the Proper HTML tags.Include the HTML tags in our Code.Cross-check the Scraped Data.Oct 27, 2020

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