Happy new year, and happy new upgrade! Django has issued a new security release today. This is the first set of security fixes that I’ve been involved in, so I thought I’d take the opportunity to explain the issues in a bit more depth.
This post is not about importing typing.Optional, but instead imports that are themselves optional. Libraries often have optional dependencies, and the code should work whether or not the import is there. A common pattern to solve this to catch ImportError and replace the module with None:
If you use Gunicorn, it’s likely you have a configuration file. This is a Python module that contains settings as module-level variables. Here’s an example with some essential settings:
Hitting “refresh” to see your changes is an instinct many web developers develop. But it’s a small waste of time that adds up to many hours per year spent waiting. It’s a sub-optimal development experience (DX).
Developer Experience (DX) is a catch-all term for anything that can improve your development workflow. Such improvements can help you write better code, faster, with fewer bugs.
Here are some Django-related deals for this year’s Black Friday (26th Nov) and Cyber Monday (29th Nov), including my own.
Joel Spolsky’s infamous Joel Test is a quick heuristic test for checking a software engineering team’s technical chops. I’ve come up with a similar test that we can use to decide whether a new package we’re considering depending on is well-maintained.
The preface of Software Engineering at Google opens with this thesis:
The descriptor protocol allow us to completely customize attribute access. Python’s documentation describes the protocol with types involved described with words. Let’s look at how we can write those as type hints.
Earlier this week I shared my Python script template. Here’s an extended version with sub-command support, and an example script.
When dealing with evolvng APIs, it may be useful to rename an attribute in a class, but keep the old name around for backwards compatibility. This would mean making one attribute an alias for another. In this post we’ll look at two ways to achieve this.
functools.partial() in DjangoI remain convinced that Python’s functools.partial() is underappreciated. Following my previous post, here are three more ways to use partial() with Django.
It’s fundamentally useful to exit your program when it’s done. Here are five(!) ways to do so in Python.
Python is great for writing scripts for the command line. In this post we’ll look at my script template, an example script, and some alternative versions (without type hints, and in async flavour).
print()If you’re embarrassed at debugging with print(), please don’t be - it’s perfectly fine! Many bugs are easily tackled with just a few checks in the right places. As much as I love using a debugger, I often reach for a print() statement first.
Django 4.0 had its first alpha release last week and the final release should be out in December. It contains an abundance of new features, which you can check out in the release notes. In this post we’ll look at the changes to testing in a bit more depth.
I recently converted this blog to Pelican, a Python powered static site generator. On the way I added a few customizations. One customization is a Jinja template filter to truncate a post’s HTML as a summary, using Python’s HTMLParser class. Here’s how I wrote it.
Sometimes pip install will flag a warning saying “The candidate selected for download or install is a yanked version”. For example, if we install attrs version 21.1.0:
Many languages follow the syntax of C, and use semicolons to indicate the end of a statement. For example, in JavaScript:
Take this function:
Django deprecates a small list of features with every feature release, requiring us to update our projects, which can be monotonous. Today I’m announcing a new tool I’ve created, django-upgrade, that automates some of this drudgery for us all.
When Lambda@Edge first came out, I added it to my blog’s CloudFront distribution in order to add security headers. Then, when Lambda@Edge added Python support, I converted my function from JavaScript to Python.
Black is the de facto standard code formatter for Python, and these days I use it on all my projects. blacken-docs is a tool that also allows you to apply Black to code samples in your docs. I recently rolled it out on my projects to great effect.
I started this blog in 2014 using the popular Jekyll. Whilst it served me well, I’ve wanted to migrate to a Python-based tool for a while now, for a few reasons:
types moduleWriting type hints gives us some familiarity with the typing module. But Python also includes the similarly-named types module, which can also come in handy. Let’s look at the history of these two modules, some use cases of types, and one way in which it’s not so useful.