Simon Willison’s Weblog

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. # 3rd April 2024, 2:58 pm

Python packaging must be getting better—a datapoint (via) Luke Plant reports on a recent project he developed on Linux using a requirements.txt file and some complex binary dependencies—Qt5 and VTK—and when he tried to run it on Windows... it worked! No modifications required.

I think Python’s packaging system has never been more effective... provided you know how to use it. The learning curve is still too high, which I think accounts for the bulk of complaints about it today. # 22nd January 2024, 6:06 pm

You can stop using user-scalable=no and maximum-scale=1 in viewport meta tags now. Luke Plant points out that your meta viewport tag should stick to just “width=device-width, initial-scale=1” these days—the user-scalable=no and maximum-scale=1 attributes are no longer necessary, and have a negative impact on accessibility, especially for Android users. # 4th August 2023, 11:41 pm

The different uses of Python type hints (via) Luke Plant describes five different categories for how Python optional types are being used today: IDE assistants, type checking, runtime behavior changes via introspection (e.g. Pydantic), code documentation, compiler instructions (ala mypyc)—and a bonus sixth, dependency injection. # 7th April 2023, 2:17 am

Python’s “Disappointing” Superpowers. Luke Plant provides a fascinating detailed list of Python libraries that use dynamic meta-programming tricks in interesting ways—including SQLAlchemy, Django, Werkzeug, pytest and more. # 1st February 2023, 10:41 pm

pyfakefs usage (via) New to me pytest fixture library that provides a really easy way to mock Python’s filesystem functions—open(), os.path.listdir() and so on—so a test can run against a fake set of files. This looks incredibly useful. # 1st February 2023, 10:37 pm

YAGNI exceptions (via) Luke Plant provides his collection of things that you probably ARE going to need in a project, where adding them later is painful enough that it’s worth the up-front investment. I really like these as a concept, and I’m coining the term PAGNI—for Probably Are Gonna Need It—to describe them. # 1st July 2021, 6:30 pm

Changeset 8162. “Implemented a secure password reset form that uses a token and prompts user for new password”—also sneaks base36 encoding and decoding in to Django. # 31st July 2008, 10:54 pm