Blog Posts by Andrew B. Collier / @datawookie

Unravelling Transparency in Coverage Data

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.

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What is Transparency in Coverage Data?

The Transparency in Coverage Act (bill currently before congress) is a set of regulations that aim to increase transparency in health insurance coverage in the USA. The primary goal of the act is to provide consumers with clear, accessible, and actionable information about the cover that they receive from their health insurance. What services are included? How much will the insurer pay for a specific service? And how does this change from one provider to another? Or from one geographic region to another? Answers to these kinds of questions were previously hard, if not impossible, for a consumer to access.

In principle the information covered by the regulations should include costs, benefits, and other essential details. It should ensure that consumers can make informed healthcare decisions and understand the financial implications of their choices.

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Controlling what Alembic Autogenerates

Alembic can autogenerate migrations. This is probably its most valuable feature. However, I had a situation where --autogenerate kept on creating migrations for the databasechangelog and databasechangeloglock tables. These are Liquibase tables and should never feature in the Alembic migrations.

The solution was to tell Alembic to ignore these tables by updating the module.

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Kayak Specifications

The data in the table below gives (manufacturer) specifications for a selection of kayaks and canoes. The data were originally compiled from two sources:

The data has been revised and expanded to include other manufacturers and more recent models. It has also been cleaned to some extent, but there is still work to be done. Please let me know if you spot any errors or omissions.

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Column Order: Inheritance & Declarative Base

I prefer to have my primary key columns first in a table. I recognise that column order is irrelevant to the performance of the table, but I prefer this for personal aesthetic reasons. However, from SQLAlchemy 2.0.0 there’s a change in the way that column order works with inherited base classes.

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Using mailmap to Tidy Git Contributors

Do you ever contribute to a Git repository from different machines? Yeah, you probably do. Sometimes you’re on your work machine. Other times you’re on your personal laptop. Or your gaming desktop. And you might have a different Git identity on each of those. And this means that your Git log ends up looking a bit messy. Who are all of these people with similar names but different email addresses? A .mailmap file can be used to tidy things up.

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Developing a Gatsby Site with Docker

Getting Gatsby (also GatsbyJS) installed and running can be a challenge. With older versions of Ubuntu I have fought extensively with Node package versions. Docker seems to be a natural solution. This post shows how to build and run a simple Docker image for serving a development Gatsby site.

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Configuring BASH History

If you use BASH, then you’re probably already using the command history. BASH history allows you to access a list of previous commands executed in the shell. It can make you more productive and efficient: do more and do it quicker.

The default configuration of BASH history will suit most purposes. But, like most things in the Linux universe, it’s possible to tweak that configuration to suit your specific requirements. In this post I’ll present some of those configuration options.

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Chrome DevTools Protocol & Selenium

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.

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Undetected ChromeDriver: Stay Below the Radar

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.

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