I’ve recently dropped Python 2 support from most of the open source projects I maintain. Python 2 support ends 2020-01-01 (see pythonclock.org), and many major projects have signed the Python 3 Statement that declares that they will remove Python 2 support before, so this year is crunch time for migration.
It’s quite common to want to pip install a version of a package that hasn’t been released to PyPI, but is available on its Git repository host, such as GitHub. If the package is pure Python or has a relatively simple build process, you can normally install it directly via Git.
I realized I’ve posted the 2017 and 2018 editions of the London Django Meetup December quizzes on my blog, but forgot to post the first one in 2016. So here it is reproduced below, if you’d like to play at home or scroll through to the answers to pick up on some more Django trivia.
The TV program Black Mirror released an interactive choose-your-own-adventure film on Netflix called Bandersnatch over the holiday period. I enjoyed playing through it and finding the various endings, especially since I recently played The Stanley Parable which is in the same genre but with more humour. Bandersnatch has many endings and easter eggs, so naturally there’s a whole subreddit dedicated to tracking them down. The most impressive is an embedded Spectrum tape noise containing a QR code that leads to a real ZX Spectrum game made in 2018 by developer Matt Wescott.
Reading the Django 2.2 alpha announcement, the phrase “salmagundi of new features” stood out to me. I had to look up “salmagundi” in Wiktionary, where it is defined as:
On Monday evening I gave a quiz at the December London Django Meetup Group for the third year running - that makes it a tradition! Here it is so you can follow it at home - answers are at the bottom, no cheating.
I just got a Yubikey for security at work. It’s a neat little device, and the way it sends one time passwords to your computer is by presenting as a vanilla USB keyboard and sending keystrokes. Pressing its single button types out a fresh one time password.
Here are some sites that are useful for checking your internet connection. I tend to need them when connecting to any new Wi-Fi.
This is about a small problem we faced with the models used for customers in YPlan, now Time Out Checkout.
Update (2025-06-01): The above feed is no longer available.
This is a problem I've seen several times over the past few years.
My plugin pytest-randomly was recently moved into the pytest-dev organization on GitHub, making it a bit “more official” as a pytest plugin. Thanks to Bruno Oliveira for suggesting it, Florian Bruhin and Bruno for approving it on the pytest-dev mailing list, and Gordon Wrigley for helping with its development.
Yesterday evening I gave a quiz at the London Django Meetup Group for the second year running. Here it is so you can do it at home (no cheating!). Answers are at the bottom.
I’m writing code for a little Raspberry Pi HUD I’m running in my house, project ‘Homehud’. Naturally I manage the Raspbian system I’ve installed on it with Ansible.
Django’s ORM is normally fast enough as-is, but if you’ve ever profiled a high traffic view with a fairly complicated query, you might have found that constructing QuerySet can take a noticeable portion of your request time. For example, I once found a query on the front page of the site I was working on that took 1ms to construct and 1ms for the database to answer. With a performance budget of 100ms, that was 1% gone on computing the exactly same SQL.
I maintain a few Python projects on Github + PyPI. I try to keep them as consistent and error-free as possible and thus running code quality tools (known as ‘linters’) such as flake8 and isort to ensure this happens. I also discovered the lesser known python setup.py check which has found a number of problems I otherwise wouldn’t have found until release time - highly recommended!
AWS just announced Amazon H3 (the Highly Hospitable Hotel), available now in us-east-1 and coming years later to the region you actually use. They’re leveraging all the infrastructure they have built for their data centres to create a new style of ‘pay as you go’ hotel. Here are some of the features and pricing schemes available at launch:
During PyCon UK I had the opportunity to work on open-sourcing our in-house Django performance testing tool, which has now been released as django-perf-rec. We created it over two years ago, and have been using and improving it since. It has been helping us to pre-emptively fix performance problems in our code, and now it can help you!
We recently upgraded our 160,000 lines of backend Python code from Python 2 to Python 3. We did with zero downtime and no major errors! Here’s how we did it, hopefully it will help anyone else still stuck on Python 2!
At YPlan we love Ansible. We use it for controlling our various AWS instances and other services, as well as with Vagrant for development environments that are in sync. This way if we want to upgrade a system package or piece of configuration, it needs only be written once in Ansible before being applied everywhere.
AWS Lambda is a hip “serverless” technology that everyone is talking about. While I find ‘serverless’ a bit of a funny name—it just means a managed environment—I like using Lambda functions for infrastructure glue or running small internal applications. Putting these things on individually managed servers of their own has always been a pain, so Lambda is a perfect fit.
Python 3 includes a faster re-implementation of the decimal standard library, called cdecimal. How much faster?
I recently reduced the YPlan build time by about 30% by tuning two Ansible settings. They’re not on by default, but work in most setups, so this will make a nice short guide on going faster.
I recently released version 0.1.10 of my library django-mysql, for which the main new feature was a backend for Django’s cache framework called MySQLCache. This post covers some of the inspiration and improvements it has, as well as a basic benchmark against Django’s built-in DatabaseCache.
I showed this briefly in my post on merging groups and hostvars, but I thought it was worth writing a whole post on. The Minimum Viable Playbook (MVP) is the shortest, most useful Ansible playbook I have. Whenever I need to write some Ansible code and I’m not entirely sure I’m doing it right (which is often), I implement it first in the MVP so I can test it quickly. Here’s my latest iteration: