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Screen Scraping with Node.js

Screen Scraping with Node.js
You may have used NodeJS as a web server, but did you know that you can also use it for web scraping? In this tutorial, we'll review how to scrape static web pages - and those pesky ones with dynamic content - with the help of NodeJS and a few helpful NPM modules. Web scraping has always had a negative connotation in the world of web development - and for good reason. In modern development, APIs are present for most popular services and they should be used to retrieve data rather than scraping. The inherent problem with scraping is that it relies on the visual structure of the page being scraped. Despite these flaws, it's important to learn a bit about web scraping and some of the tools available to help with this task. Note: If you can't get the information you require through an API or a feed, it's a good sign that the owner does not want that information to be accessible. Scrapers can be written in any language, really. Let's start with the simple use-case: static web pages. Related:  node.js

Scraping the Web Using Node.js An important part of a data analyst's work is gathering data. Sometimes you might get it in a nice, machine readable format (XML, JSON, CVS, you name it). There are times when you have to work a little to get the data in a decent format. Node.js + Cheerio + Request - a Great Combo As it happens Node.js and associated technologies are a great fit for this purpose. These days I like to use combination of cheerio and request. Basic Workflow When it comes to scraping the basic workflow is quite simple. Examples sonaatti-scraper scrapes some restaurant data. There is some room for improvement. My other example, jklevents, is based on zombie cheerio. In my third example, f500-scraper, I had to use a combination of tools as zombie didn't quite work. lte-scraper uses cheerio and request. Other Considerations When scraping, be polite. This is just a point I wanted to make as there are times when good things can come out of these sort of things. Conclusion Node.js is an amazing platform for scraping.

How To Use node.js, request and cheerio to Set Up Simple Web-Scraping Introduction: In this tutorial, we will scrape the front page of Hacker News to get all the top ranking links as well as their metadata - such as the title, URL and the number of points/comments it received. This is one of many techniques to extract data from web pages using node.js and mainly uses a module called cheerio by Matthew Mueller which implements a subset of jQuery specifically designed for server use. Cheerio is lightweight, fast, flexible and easy to use, if you're already accustomed to working with jQuery. We will also make use of Mikael Rogers' excellent request module as a simplified HTTP client. Requirements: I will assume that you're already familiar with node.js, jQuery and basic Linux administrative tasks like connecting to your VPS using SSH. If you're unfamiliar with node.js or if you haven't installed it yet, please refer to the Articles & Tutorials section above to find installation instructions for your operating system. Code: npm install request cheerio That's it!

Web Development Course Online - How To Build A Blog When does the course begin? This class is self paced. You can begin whenever you like and then follow your own pace. It’s a good idea to set goals for yourself to make sure you stick with the course. How long will the course be available? This class will always be available! How do I know if this course is for me? Take a look at the “Class Summary,” “What Should I Know,” and “What Will I Learn” sections above. Can I skip individual videos? Yes! What are the rules on collaboration? Collaboration is a great way to learn. Why are there so many questions? Udacity classes are a little different from traditional courses. What should I do while I’m watching the videos? Learn actively! Scraping · chriso/ Wiki includes a robust framework for scraping data from the web. The primary methods for scraping data are get and getHtml, although there are methods for making any type of request, modifying headers, etc. See the API for a full list of methods. A note before you start scraping The --debug switch is your friend - use it to see the request and response headers, and whether there was an error with the request. --debug my_scraping_job Example 1: Save a web page to disk save.js nodeio = require '' class SavePage extends nodeio.JobClass input: false run: () -> url = @options.args[0] @get url, (err, data) => if err? To save a page to disk, run $ -s save " > google.html Which is equivalent to $ curl " > google.html Example 2: Get the number of Google results for a list of keywords keywords.js Note: you can also override the input at the command line using the -i switch, e.g. $ -i list_of_words.txt keywords

noodle How to Finally Play the Guitar: 80/20 Guitar and Minimalist Music When will you stop dreaming and start playing? (Photo: Musician “Lights”, Credit: Shandi-lee) I’ve always wanted to play the guitar. It started as a kid, listening to my dad play around the fireplace during the holidays. But I never thought I could do it myself. Despite tackling skills as esoteric as Japanese horseback archery, I somehow put music in a separate “does not apply” category until two years ago. My fascination with guitar wasn’t rekindled until Charlie Hoehn, an employee of mine at the time, showed me the 80/20 approach to learning it. This post explains how to get the most guitar mileage and versatility in the least time… Do you have any additional tips, whether for guitar or applying the 80/20 principle to another instrument? Enter Charlie Almost everyone has fantasized about performing music in front of a huge screaming crowd at some point in their life. Comprehensive comes later. The Ground Rules 1. 2. 3. Getting Started Next, you’ll want to buy a capo. Capo on the second fret.

mikeal/request wscraper wscraper.js is a web scraper agent written in node.js and based on cheerio.js a fast, flexible, and lean implementation of core jQuery; It is built on top of request.js and inspired by http-agent.js; Usage There are two ways to use wscraper: http agent mode and local mode. HTTP Agent mode In HTTP Agent mode, pass it a host, a list of URLs to visit and a scraping JS script. var agent = wscraper.createAgent(); agent.start('', '/finance', script); wscraper.start('', ['/', '/finance', '/news'], script); The URLs should be passed as an array of strings. var util = require('util'); var wscraper = require('wscraper'); var fs = require('fs'); var script = fs.readFileSync('/scripts/googlefinance.js'); var companies = ['/finance? The scraping script should be pure client JavaScript, including JQuery selectors. At time of writing, website reports financial data of public companies as in the following html snippet: ... Local mode Happy scraping!

Web scraping with Node.js | Matt's Hacking Blog Web scraping these days is often considered a fairly well understood craft, however there are definitely some complexities that modern web sites are bringing to the table. The days of AJAX long polling, XMLHttpRequest, WebSockets, Flash Sockets etc make things a little more difficult than just your average crawler can handle. Let’s start with the basics of what we needed at Hubdoc – we are crawling bank, utilities, and credit card company web sites looking for bill amounts, due dates, account numbers, and most importantly, PDFs of most recent bills. How would we build this? For some web sites this worked. At that point after much frustration I reached for node-phantomjs, which allowed me to control the phantomjs headless webkit web browser from node. It only tells you if a page has finished loading, but you have no idea if it is about to redirect via some JavaScript or meta tag. Web sites dick around with things like console.log(), redefining them to their own whim. if (! Like this:

Easy Web Scraping With Node.js Web scraping is a technique used to extract data from websites using a computer program that acts as a web browser. The program requests pages from web servers in the same way a web browser does, and it may even simulate a user logging in to obtain access. It downloads the pages containing the desired data and extracts the data out of the HTML code. In this article I'm going to show you how to write web scraping scripts in Javascript using Node.js. Why use web scraping? Here are a few of examples where web scraping can be useful: You have several bank accounts with different institutions and you want to generate a combined report that includes all your accounts.You want to see data presented by a website in a different format. Web scraping can also be used in ways that are dishonest and sometimes even illegal. In this article I'm going to show you a practical example that implements this technique. Tools for web scraping For example, consider the following HTML page: <html><head>... What?