561 items tagged “django”
The Django web framework.
2024
If we had $1,000,000…. Jacob Kaplan-Moss gave my favorite talk at DjangoCon this year, imagining what the Django Software Foundation could do if it quadrupled its annual income to $1 million and laying out a realistic path for getting there. Jacob suggests leaning more into large donors than increasing our small donor base:
It’s far easier for me to picture convincing eight or ten or fifteen large companies to make large donations than it is to picture increasing our small donor base tenfold. So I think a major donor strategy is probably the most realistic one for us.
So when I talk about major donors, who am I talking about? I’m talking about four major categories: large corporations, high net worth individuals (very wealthy people), grants from governments (e.g. the Sovereign Tech Fund run out of Germany), and private foundations (e.g. the Chan Zuckerberg Initiative, who’s given grants to the PSF in the past).
Also included: a TIL on Turning a conference talk into an annotated presentation. Jacob used my annotated presentation tool to OCR text from images of keynote slides, extracted a Whisper transcript from the YouTube livestream audio and then cleaned that up a little with LLM and Claude 3.5 Sonnet ("Split the content of this transcript up into paragraphs with logical breaks. Add newlines between each paragraph."
) before editing and re-writing it all into the final post.
Django Commons. Django Commons is a really promising initiative started by Tim Schilling, aimed at the problem of keeping key Django community projects responsibly maintained on a long-term basis.
Django Commons is an organization dedicated to supporting the community's efforts to maintain packages. It seeks to improve the maintenance experience for all contributors; reducing the barrier to entry for new contributors and reducing overhead for existing maintainers.
I’ve stated recently that I’d love to see the Django Software Foundation take on this role - adopting projects and ensuring they are maintained long-term. Django Commons looks like it solves that exact problem, assuring the future of key projects beyond their initial creators.
So far the Commons has taken on responsibility for django-fsm-2, django-tasks-scheduler and, as-of this week, diango-typer.
Here’s Tim introducing the project back in May. Thoughtful governance has been baked in from the start:
Having multiple administrators makes the role more sustainable, lessens the impact of a person stepping away, and shortens response time for administrator requests. It’s important to me that the organization starts with multiple administrators so that collaboration and documentation are at the forefront of all decisions.
Thoughts on the Treasurer Role at Tech NonProfits. Will Vincent, Django Software Foundation treasurer from 2020-2022, explains what’s involved in the non-profit role with the highest level of responsibility and trust.
Building an automatically updating live blog in Django. Here's an extended write-up of how I implemented the live blog feature I used for my coverage of OpenAI DevDay yesterday. I built the first version using Claude while waiting for the keynote to start, then upgraded it during the lunch break with the help of GPT-4o to add sort options and incremental fetching of new updates.
Weeknotes: Three podcasts, two trips and a new plugin system
I fell behind a bit on my weeknotes. Here’s most of what I’ve been doing in September.
[... 693 words]Ensuring a block is overridden in a Django template (via) Neat Django trick by Tom Carrick: implement a Django template tag that raises a custom exception, then you can use this pattern in your templates:
{% block title %}{% ensure_overridden %}{% endblock %}
To ensure you don't accidentally extend a base template but forget to fill out a critical block.
DjangoTV (via) Brand new site by Jeff Triplett gathering together videos from Django conferences around the world. Here's Jeff's blog post introducing the project.
Themes from DjangoCon US 2024
I just arrived home from a trip to Durham, North Carolina for DjangoCon US 2024. I’ve already written about my talk where I announced a new plugin system for Django; here are my notes on some of the other themes that resonated with me during the conference.
[... 1,470 words]django-plugin-datasette. I did some more work on my DJP plugin mechanism for Django at the DjangoCon US sprints today. I added a new plugin hook, asgi_wrapper(), released in DJP 0.3 and inspired by the similar hook in Datasette.
The hook only works for Django apps that are served using ASGI. It allows plugins to add their own wrapping ASGI middleware around the Django app itself, which means they can do things like attach entirely separate ASGI-compatible applications outside of the regular Django request/response cycle.
Datasette is one of those ASGI-compatible applications!
django-plugin-datasette
uses that new hook to configure a new URL, /-/datasette/
, which serves a full Datasette instance that scans through Django’s settings.DATABASES
dictionary and serves an explore interface on top of any SQLite databases it finds there.
It doesn’t support authentication yet, so this will expose your entire database contents - probably best used as a local debugging tool only.
I did borrow some code from the datasette-mask-columns plugin to ensure that the password
column in the auth_user
column is reliably redacted. That column contains a heavily salted hashed password so exposing it isn’t necessarily a disaster, but I like to default to keeping hashes safe.
DJP: A plugin system for Django
DJP is a new plugin mechanism for Django, built on top of Pluggy. I announced the first version of DJP during my talk yesterday at DjangoCon US 2024, How to design and implement extensible software with plugins. I’ll post a full write-up of that talk once the video becomes available—this post describes DJP and how to use what I’ve built so far.
[... 1,664 words]nanodjango. Richard Terry demonstrated this in a lightning talk at DjangoCon US today. It's the latest in a long line of attempts to get Django to work with a single file (I had a go at this problem 15 years ago with djng) but this one is really compelling.
I tried nanodjango out just now and it works exactly as advertised. First install it like this:
pip install nanodjango
Create a counter.py
file:
from django.db import models from nanodjango import Django app = Django() @app.admin # Registers with the Django admin class CountLog(models.Model): timestamp = models.DateTimeField(auto_now_add=True) @app.route("/") def count(request): CountLog.objects.create() return f"<p>Number of page loads: {CountLog.objects.count()}</p>"
Then run it like this (it will run migrations and create a superuser as part of that first run):
nanodjango run counter.py
That's it! This gave me a fully configured Django application with models, migrations, the Django Admin configured and a bunch of other goodies such as Django Ninja for API endpoints.
Here's the full documentation.
UV — I am (somewhat) sold
(via)
Oliver Andrich's detailed notes on adopting uv
. Oliver has some pretty specific requirements:
I need to have various Python versions installed locally to test my work and my personal projects. Ranging from Python 3.8 to 3.13. [...] I also require decent dependency management in my projects that goes beyond manually editing a
pyproject.toml
file. Likewise, I am way too accustomed topoetry add ...
. And I run a number of Python-based tools --- djhtml, poetry, ipython, llm, mkdocs, pre-commit, tox, ...
He's braver than I am!
I started by removing all Python installations, pyenv, pipx and Homebrew from my machine. Rendering me unable to do my work.
Here's a neat trick: first install a specific Python version with uv
like this:
uv python install 3.11
Then create an alias to run it like this:
alias python3.11 'uv run --python=3.11 python3'
And install standalone tools with optional extra dependencies like this (a replacement for pipx
and pipx inject
):
uv tool install --python=3.12 --with mkdocs-material mkdocs
Oliver also links to Anže Pečar's handy guide on using UV with Django.
New Django {% querystring %} template tag. Django 5.1 came out last week and includes a neat new template tag which solves a problem I've faced a bunch of times in the past.
{% querystring color="red" size="S" %}
Adds ?color=red&size=S
to the current URL - keeping any other existing parameters and replacing the current value for color
or size
if it's already set.
{% querystring color=None %}
Removes the ?color=
parameter if it is currently set.
If the value passed is a list it will append ?color=red&color=blue
for as many items as exist in the list.
You can access values in variables and you can also assign the result to a new template variable rather than outputting it directly to the page:
{% querystring page=page.next_page_number as next_page %}
Other things that caught my eye in Django 5.1:
- PostgreSQL connection pools.
- The new LoginRequiredMiddleware for making every page in an application require login.
- The SQLite database backend now accepts init_command for settings things like
PRAGMA cache_size=2000
on new connections. - SQLite can also be passed
"transaction_mode": "IMMEDIATE"
to configure the behaviour of transactions.
django-http-debug, a new Django app mostly written by Claude
Yesterday I finally developed something I’ve been casually thinking about building for a long time: django-http-debug. It’s a reusable Django app—something you can pip install
into any Django project—which provides tools for quickly setting up a URL that returns a canned HTTP response and logs the full details of any incoming request to a database table.
Announcing our DjangoCon US 2024 Talks! I'm speaking at DjangoCon in Durham, NC in September.
My accepted talk title was How to design and implement extensible software with plugins. Here's my abstract:
Plugins offer a powerful way to extend software packages. Tools that support a plugin architecture include WordPress, Jupyter, VS Code and pytest - each of which benefits from an enormous array of plugins adding all kinds of new features and expanded capabilities.
Adding plugin support to an open source project can greatly reduce the friction involved in attracting new contributors. Users can work independently and even package and publish their work without needing to directly coordinate with the project's core maintainers. As a maintainer this means you can wake up one morning and your software grew new features without you even having to review a pull request!
There's one catch: information on how to design and implement plugin support for a project is scarce.
I now have three major open source projects that support plugins, with over 200 plugins published across those projects. I'll talk about everything I've learned along the way: when and how to use plugins, how to design plugin hooks and how to ensure your plugin authors have as good an experience as possible.
I'm going to be talking about what I've learned integrating Pluggy with Datasette, LLM and sqlite-utils. I've been looking for an excuse to turn this knowledge into a talk for ages, very excited to get to do it at DjangoCon!
Django: Test for pending migrations
(via)
Neat recipe from Adam Johnson for adding an automated test to your Django test suite that runs manage.py makemigrations --check
to ensure you don't accidentally land code that deploys with a missing migration and crashes your site. I've made this mistake before myself so I'll be adding this to my projects.
Optimal SQLite settings for Django
(via)
Giovanni Collazo put the work in to figure out settings to make SQLite work well for production Django workloads. WAL mode and a busy_timeout
of 5000 make sense, but the most interesting recommendation here is "transaction_mode": "IMMEDIATE"
to avoid locking errors when a transaction is upgraded to a write transaction.
Giovanni's configuration depends on the new "init_command"
support for SQLite PRAGMA options introduced in Django 5.1alpha.
Django Enhancement Proposal 14: Background Workers. Jake Howard's DEP has been approved and is moving into the implementation stage.
Django doesn't have a first-party solution for long-running tasks, however the ecosystem is filled with incredibly popular frameworks, all of which interact with Django in slightly different ways. Other frameworks such as Laravel have background workers built-in, allowing them to push tasks into the background to be processed at a later date, without requiring the end user to wait for them to occur. [...]
This proposal sets out to provide an interface and base implementation for long-running background tasks in Django.
Jake has an illustrative reference implementation called django-tasks.
Enforcing conventions in Django projects with introspection (via) Luke Plant shows how to use the Django system checks framework to introspect models on startup and warn if a DateTime or Date model field has been added that doesn’t conform to a specific naming convention.
Luke also proposes “*_at” as a convention for DateTimes, contrasting with “*_on” or “*_date” (I prefer the latter) for Dates.
Talking about Django’s history and future on Django Chat (via) Django co-creator Jacob Kaplan-Moss sat down with the Django Chat podcast team to talk about Django’s history, his recent return to the Django Software Foundation board and what he hopes to achieve there.
Here’s his post about it, where he used Whisper and Claude to extract some of his own highlights from the conversation.
DiskCache (via) Grant Jenks built DiskCache as an alternative caching backend for Django (also usable without Django), using a SQLite database on disk. The performance numbers are impressive—it even beats memcached in microbenchmarks, due to avoiding the need to access the network.
The source code (particularly in core.py) is a great case-study in SQLite performance optimization, after five years of iteration on making it all run as fast as possible.
Django Chat: Datasette, LLMs, and Django. I’m the guest on the latest episode of the Django Chat podcast. We talked about Datasette, LLMs, the New York Times OpenAI lawsuit, the Python Software Foundation and all sorts of other topics.
DSF calls for applicants for a Django Fellow. The Django Software Foundation employs contractors to manage code reviews and releases, responsibly handle security issues, coach new contributors, triage tickets and more.
This is the Django Fellows program, which is now ten years old and has proven enormously impactful.
Mariusz Felisiak is moving on after five years and the DSF are calling for new applicants, open to anywhere in the world.
2023
Database generated columns: GeoDjango & PostGIS. Paolo Melchiorre advocated for the inclusion of generated columns, one of the biggest features in Django 5.0. Here he provides a detailed tutorial showing how they can be used with PostGIS to create database tables that offer columns such as geohash that are automatically calculated from other columns in the table.
Database Migrations. Vadim Kravcenko provides a useful, in-depth description of the less obvious challenges of applying database migrations successfully. Vadim uses and likes Django’s migrations (as do I) but notes that running them at scale still involves a number of thorny challenges.
The biggest of these, which I’ve encountered myself multiple times, is that if you want truly zero downtime deploys you can’t guarantee that your schema migrations will be deployed at the exact same instant as changes you make to your application code.
This means all migrations need to be forward-compatible: you need to apply a schema change in a way that your existing code will continue to work error-free, then ship the related code change as a separate operation.
Vadim describes what this looks like in detail for a number of common operations: adding a field, removing a field and changing a field that has associated business logic implications. He also discusses the importance of knowing when to deploy a dual-write strategy.
Building Search DSLs with Django (via) Neat tutorial by Dan Lamanna: how to build a GitHub-style search feature—supporting modifiers like “is:open author:danlamanna”—using PyParsing and the Django ORM.
Writing a chat application in Django 4.2 using async StreamingHttpResponse, Server-Sent Events and PostgreSQL LISTEN/NOTIFY (via) Excellent tutorial by Víðir Valberg Guðmundsson on implementing chat with server-sent events using the newly async-capable StreamingHttpResponse from Django 4.2x.
He uses PostgreSQL’a LISTEN/NOTIFY mechanism which can be used asynchronously in psycopg3—at the cost of a separate connection per user of the chat.
The article also covers how to use the Last-Event-ID header to implement reconnections in server-sent events, transmitting any events that may have been missed during the time that the connection was dropped.
Django 4.2 released. “This version has been designated as a long-term support (LTS) release, which means that security and data loss fixes will be applied for at least the next three years.” Some neat new async features, including improvements to async streaming responses.
djngo.com: Portable Django (via) “A 20mb executable zip file with Python 3.6 and Django 2.2. Works on Windows, Linux, MacOSX with x86_64 and aarch64 (yes, Apple M1 and Raspberry Pi).” The latest wizardry from the ecosystem surrounding the Cosmopolitan project, which provides a should-be-impossible mechanism for running the same executable on a bunch of different platforms. This utility by Ariel Núñez bundles Python and Django and SQLite, such that a Django application can become a portable executable ready to run on multiple platforms. It’s currently limited to Python 3.6 and Django 2.2 since those are the versions that run under Cosmopolitan, but I expect we’ll see more recent versions of those dependencies in the future.
How to simulate a broken database connection for testing in Django (via) Neil Kakkar explores the options using unittest.patch() and then settles on a neater pattern using “with connection.execute_wrapper(QueryTimeoutWrapper()):” to simulate the exact exception he needs to test against.