mike.depalatis.net - Articles

Make refactoring tests easier

Quite often when I see unit tests written by colleagues I’ll see this sort of pattern:

Using ART with Wayland

Lately I’ve been experimenting with using ART, a raw photo editing application which is a fork of RawTherapee. Compared to the excellent Darktable, ART has a slightly easier learning curve and can yield decent results pretty quickly. The binaries provided…

Ensuring timestamp storage in UTC with SQLAlchemy

Naively one might think that using defining a column with DateTime(timezone=True) when defining a SQL table with SQLAlchemy would result in a timezone-aware datetime object when loading into Python from the database. This doesn’t always work however, in particular when using SQLite. Note the…

Useful BASH shortcuts for conda

Anaconda’s conda has become the de facto environment management tool in Python-oriented scientific computing. Its lightweight environments are suitable for development and, at least in some…

Jupyter integration with conda environments

How to create new Jupyter notebooks with different conda environments:

Multiline lambdas

Although Python has anonymous lambda functions, they lack the flexibility that some languages such as Javascript or even modern C++ have. In Python, lambda functions are…

Sharing data between processes with SQLite

Because of the global interpreter lock in CPython, it is sometimes beneficial to…

Simplifying argparse usage with subcommands

One of the best things about Python is its standard…

Javascript for Python programmers

Unless you’re just writing a simple HTTP API server, any amount of web programming in Python will likely require at least a little bit of Javascript. Like it or not (and I…

Getting Matplotlib’s colors in order

Matplotlib can be very easy to use at times, especially if you just want to make a simple “y vs. x” type of plot. But when it comes to specialized customization, it can be a bit…

Fitting with lmfit

General-purpose fitting in Python can sometimes be a bit more challenging than one might at first suspect given the robust nature of tools like Numpy and Scipy. First we had least…

Using Postgres as a time series database

Time series databases (TSDBs) are quite popular these days. To name a few, there are InfluxDB, Graphite, Druid, Kairos, and Prometheus. All aim to optimize data storage and querying for time-based data, which is highly relevant in a physics labs where there are multitude of “metrics” (to borrow a phrase…

Importing one Mercurial repository into another

In the ion trap group, we usually use Mercurial for version controlling software we write for experimental control, data analysis, and so on. This post outlines how to import the full history of one…

Running (possibly) blocking code like a Tornado coroutine

One of the main benefits of using the Tornado web server is that it is (normally) a single-threaded, asynchronous framework that can rely on coroutines…

Background tasks with Tornado

I have been using Tornado lately for distributed control of devices in the lab where an asynchronous framework is advantageous. In particular, we have a HighFinesse wavel…

Flask and server-sent events

I recently discovered the existence of the HTML5 server-sent events standard. Although it lacks the bidirectional communications of a websocket, SSE is perfect for the publish-subscribe networking pattern. This pattern just so happens to…

Using websockets with Flask via Tornado

I’ve been working on some projects for the lab that involve remotely controlling hardware to…

ssh-agent for sudo authentication with a passwordless account

Raspberry Pi as a USB to Ethernet Gateway

One of the most convenient ways of communicating with experimental devices (such as oscilloscopes, frequency generators, pulse generators, etc.) is via ethernet. The…