Blog Posts by Andrew B. Collier / @datawookie

Do you do any web scraping? If so, then you probably spend a lot of time scratching around in your browser’s Developer Tools, figuring out the DOM structure and understanding how various bits of a site are delivered. Wouldn’t it be cool to access the Developer Tools functionality from inside your scraper? Well, you can. The Chrome DevTools Protocol (CDP) provides a low-level interface for interacting with Chrome. And you can tap into that interface via Selenium.

Message IDs (MIDs) and Content IDs (CIDs) are used to identify and refer to email messages and specific pieces of content within those messages. They are formally described in RFC 2392.

The {emayili} package already has adapters which make it simple to send email via a variety of services. I have just added an adapter for the ZeptoMail transactional email service. The adapter is available in {emayili} version 0.7.13.

I recently upgraded to Ubuntu 22.10. Everything went very smoothly, but there are some minor teething problems. One of them is getting the AWS Workspace client to work. This is how I fixed that.

There’s one major problem with ChromeDriver: anti-bot services are able to detect that a browser session is being automated (as opposed to being used by a regular meat sack) and will often impose restrictions or deny connections altogether. The Undetected ChromeDriver (undetected-chromedriver) Python package is a patched version of ChromeDriver which avoids triggering a selection of anti-bot services, allowing it to glide under the anti-bot radar.

At Fathom Data we have been doing a lot of automated documentation and automated reporting. Although many of these documents are rendered to HTML, there’s an increasing demand for PDF documents. So we’ve had to raise out game in that department. The {pagedown} package has become invaluable. This is a short note showing how we tweak the page size and margins for PDF documents.

I’m a density plot devotee. And, using geom_density() from {ggplot2} these plots are effortless to produce. However, sometimes the results of geom_density() are not exactly what I’m after. Here’s how I tweak them to give me precisely what I need.

From time to time I find empty paragraph tags (<p></p>) inserted into my HTML when knitting an R Markdown document.

I’m not a web developer. However, I do regularly use HTML and CSS to layout pages which are then transformed into PDF documents. One of the requirements that I encounter fairly often is vertically aligning images and text. Fairly often, but not often enough to remember the solution. So I inevitably have to rediscover the solution (thanks StackOverflow!). Jotting this down for posterity.

In the previous post we looked at how to apply a linter and styler to a Python Project. Now we’re going to do the same for an R project. We’ll use the {precommit} R package to make the setup a breeze.

A linter and a styler can help you to write cleaner and more consistent code. In this post we’ll look at how to set up both for a Python project.

While trolling the internet aimlessly this morning, this TikTok video caught my attention.

In a previous post I took a look at some granular weather data that I acquired via the Weather API. One interesting application of these data is calculating the Fire Danger Index (FDI), which measures the degree of fire danger using information on dryness, wind speed, temperature and humidity.

A quick note on how to use the Shiny Server Docker image, rocker/shiny.

I’m a big believer in starting with the simplest possible setup, getting that to work and then adding complexity in layers. We’ll start with a simple Shiny application in app.R.

I’ve just added some more data to the {blimey} package:

• postal codes and
• postbox locations.

I’ve just added data on schools in England to the {blimey} package. The raw data were obtained from gov.uk.

Getting R set up on Linux can be somewhat frustrating. Many of the fundamental packages (like {devtools} or {remotes}) have implicit system dependencies. So installing these packages can involve numerous iterations back and forth between R and the shell while you figure out what those dependencies are and get them all installed.

I’ve been through this process many times now and finally just created a quick script that will get most of it done quickly and easily.

I’m building a model which requires historical weather data from a selection of locations in South Africa. In this post I demonstrate the process of acquiring the data and doing some simple processing.

I have a challenge: extracting data from an enormous JSON file. The structure of the file is not ideal: it’s a mapping at the top level, which means that for most standard approaches the entire document needs to be loaded before it can be processed. It would have been so much easier if the top level structure was an array. But, alas. It’s almost as if the purveyors of the data have made it intentionally inaccessible.