Topics covered in this episode:

Coverage.py regex pragmas
* Python of Yore*
* nox-uv*
* A couple Django items*
Extras
Joke

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Brian #1: Coverage.py regex pragmas

Ned Batchelder
The regex implementation of how coverage.py recognizes pragmas is pretty amazing.
It’s extensible through plugins
- covdefaults adds a bunch of default exclusions, and also platform- and version-specific comment syntaxes.
- coverage-conditional-plugin gives you a way to create comment syntaxes for entire files, for whether other packages are installed, and so on.
A change from last year (as part of coverage.py 7.6 allows multiline regexes, which let’s us do things like:
- Exclude an entire file with \\A(?s:.*# pragma: exclude file.*)\\Z
- Allow start and stop delimiters with # no cover: start(?s:.*?)# no cover: stop
- Exclude empty placeholder methods with ^\\s*(((async )?def .*?)?\\)(\\s*->.*?)?:\\s*)?\\.\\.\\.\\s*(#|$)
- See Ned’s article for explanations of these

Michael #2: Python of Yore

via Matthias

Use YORE: ... comments to highlight CPython version dependencies.

# YORE: EOL 3.8: Replace block with line 4.
if sys.version_info < (3, 9):
from astunparse import unparse
else:
from ast import unparse

Then check when they go out of support:

$ yore check --eol-within '5 months'
./src/griffe/agents/nodes/_values.py:11: Python 3.8 will reach its End of Life within approx. 4 months

Even fix them with fix .

Michael #3: nox-uv

via John Hagen
What nox-uv does is make it very simple to install uv extras and/or dependency groups into a nox session's virtual environment.
The versions installed are constrained by uv's lockfile meaning that everything is deterministic and pinned.
Dependency groups make it very easy to install only want is necessary for a session (e.g., only linting dependencies like Ruff, or main dependencies + mypy for type checking).

Brian #4: A couple Django items

Stop Using Django's squashmigrations: There's a Better Way
- Johnny Metz
- Resetting migrations is sometimes the right thing.
- Overly simplified summary: delete migrations and start over
dj-lite
- Adam Hill
- Use SQLite in production with Django
- “Simplify deploying and maintaining production Django websites by using SQLite in production. dj-lite helps enable the best performance for SQLite for small to medium-sized projects. It requires Django 5.1+.”

Extras

Brian:

Test & Code 237: FastAPI Cloud with Sebastian Ramirez
- will be out later today
pythontest.com: pytest fixtures nuts and bolts - revisited
- A blog series that I wrote a long time ago.
- I’ve updated it into more managable bite-sized pieces, updated and tested with Python 3.13 and pytest 8

Michael:

New course: Just Enough Python for Data Scientists
My live stream about uv is now on YouTube
Cursor CLI: Built to help you ship, right from your terminal.

Joke: Copy/Paste

#444 Begone Python of Yore!

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