![]() ![]() The code (as adapted from Brooke’s post) is as follows:Ĭopy this code into a text file, and save it under the name ‘scrape.js’ in the \phantomjs\bin\ folder, where your executable PhantomJS file is. So, PhantomJS needs code as an input, to tell it what URL to download the source code from. If you open the PhantomJS executable file in the \bin folder, you’ll notice that it looks something like the Command prompt terminal in Windows, or the Mac terminal. I’d recommend changing the name of the parent folder to ‘phantomjs’, just so it will be easier to recall the file path later on. The executable file for the software is found in the \bin folder. The first step is to download PhantomJS for your OS of choice and stick it somewhere easily accessible – I put it in my Documents folder. This can be used in R, as Brooke has shown in her post, but since we’re using Alteryx at The Data School, I thought I’d show how it can be utilised in Alteryx. I’m going to demonstrate a solution that I’ve adapted from a great blog post by Brooke Watson, which uses freeware called PhantomJS to allow us access the code that is pushed by JavaScript. When I disable JavaScript for the site in my example, none of my target content appears, so I’m going to assume that JavaScript is at work here. in Chrome: Settings > Advanced > Content Settings > JavaScript > Disable). A quick and dirty way to determine if JavaScript is involved in generating this content is to disable JS in your web browser, and reload the page (e.g. In fact, none of the information that we can see in the screenshot above appears in the HTML code. Have a look through the HTML code from this page and see if you can spot that house price, or any house prices at all for that matter (I’ve removed any instance of the company’s name to preserve anonymity). Let’s say we want to scrape the price information from each house listing on the page. Take for example a search results page of this property agent website. In these cases, when you view the HTML code of a website, the data that is published using JavaScript is nowhere to be seen. JavaScript is a higher-level programming language that allows websites to have increased interactivity. Tools like Alteryx and R can be used to perform these actions quite easily, by telling them which URL to read the HTML code from, and reformatting the code to output the data of interest.Ī common problem that one may encounter when scraping in this way, is when the data of interest is not contained in the HTML code, but is instead published to the website using JavaScript. In its simplest form, web scraping involves accessing the HTML code (the foundational programming language on which websites are built) of a given website, and parsing that code to extract some data. Web scraping is an extremely powerful method for obtaining data that is hosted on the web. ![]()
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