Simon Willison’s Weblog

pythondotorg/admin.py (via) There are some neat tricks in the Django application that powers Python.org (built a few years ago by RevSys). Here’s how their admin app handles creator/last_modified_by user relationships.

# 19th November 2017, 6:28 am / django

DSF calls for applicants for a Django Fellow. This is a fantastic opportunity: the Django Software Foundation’s fellowship program is providing the opportunity for a new developer to get paid to work on Django 20-40 hours a week. Tim Graham has held this position full-time for the past three years and is looking to scale back to part-time, hence this new opportunity. Applications are due by December 18, 2017.

# 16th November 2017, 10:31 pm / django, dsf

django-multitenant (via) Absolutely fascinating Django library for horizontally sharding a database using a multi-tenant pattern, from the team at Citus. In this pattern every relevant table includes a “tenant_id”, and all queries should specifically select against that ID. Once you have that in place, you can shard your rows across multiple different databases and route to the correct database based on the tenant ID, safe in the knowledge that joins will still work provided they are against other rows belonging to the same tenant.

# 16th November 2017, 9:12 pm / scaling, postgresql, django

Squeezing every drop of performance out of a Django app on Heroku. Ben Firshman describes some lesser known tricks for scaling Django on Heroku—in particular, using gunicorn gevent asynchronous workers and setting up PostgreSQL connection pooling using django-db-geventpool.

# 31st October 2017, 2:08 pm / postgresql, heroku, django

arxiv-vanity (via) Beautiful new project from Ben Firshman and Andreas Jansson: “Arxiv Vanity renders academic papers from Arxiv as responsive web pages so you don’t have to squint at a PDF”. It works by pulling the raw LaTeX source code from Arxiv and rendering it to HTML using a heavily customized Pandoc workflow. The real fun is in the architecture: it’s a Django app running on Heroku which fires up on-demand Hyper.sh Docker containers for each individual rendering job.

# 25th October 2017, 8:06 pm / docker, science, ben-firshman, django, pdf

A Brief Intro to Docker for Djangonauts (via) This is great—a really clear introduction to both Docker and Docker Compose, aimed at Django developers. Includes line-by-line annotations of an example Dockerfile and docker-compose.yml.

# 18th October 2017, 9:06 pm / docker, django

My essential django package list. Insightful list of Django packages—many of which I hadn’t seen before—by Serafeim Papastefanos, each with a handy explanation of what it’s useful for and why.

# 11th October 2017, 2:42 pm / django

Generate dynamic titles for /search/ pages. Fun little enhancement to my faceted search implementation: I now generate dynamic titles for each search results page describing the search, e.g. “Blogmarks tagged security in Feb, 2005” or ““python” in quotations tagged ruby, python in 2007”.

# 8th October 2017, 7:47 pm / facetedsearch, django

Building a statistical profiler in python. Generating flame graphs of production Python code is surprisingly straight-forward. Brian Pitts built a statistical flame graph profiler into our tikibar debugging tool at Eventbrite and it’s proved extremely useful.

# 5th October 2017, 3:44 pm / profiling, tikibar, django, python

Feature Flags, from PyCon 2014. Slides from a 15 minute talk I gave at PyCon 2014 about feature flags - what they are, how to use them and how we implemented them at both Lanyrd and Eventbrite.

This was part of a longer workshop on Advanced Django Patterns from Eventbrite and Lanyrd, which I co-presented with Andrew Godwin and Nathan Yergler.

# 10th April 2014, 6:27 pm / pycon, python, django, feature-flags, speaking