Topics covered in this episode:

* ty documentation site and uv migration guide*
* uv build backend is now stable + other Astral news*
* Refactoring long boolean expressions*
* fastapi-ml-skeleton*
Extras
Joke

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About the show

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Michael #1: ty documentation site and uv migration guide

via Skyler Kasko
Astral created a documentation site for ty (PR #744 in release 0.0.1-alpha.13).
Astral added a page on migrating from pip to a uv project in the uv documentation. (PR #12382 in release 0.7.19).
Talk Python episode on ty.

Brian #2: uv build backend is now stable + other Astral news

The uv build backend is now stable
- Tim Hopper via Python Developer Tooling Handbook
From Charlie Marsh
- “The uv build backend is now stable, and considered ready for production use. An alternative to setuptools, hatchling, etc. for pure Python projects, with a focus on good defaults, user-friendly error messages, and performance. When used with uv, it's 10-35x faster.”
- “(In a future release, we'll make this the default.)”
```
[build-system]
requires = ["uv_build>=0.7.19,<0.8.0"]
build-backend = "uv_build"
```
- I believe it’s faster, but I agree with Brett Cannon in asking “What's being benchmarked? I'm not sure what a "backend sync" is referring to other than maybe installing the build back-end?”
See also: uv: Making Python Local Workflows FAST and BORING in 2025 - Hynek

Brian #3: Refactoring long boolean expressions

Trey Hunner
This is applied boolean logic, and even folks who learned this in a CS program probably did so early on, and may have forgotten it.
How can you improve the readability of long Boolean expressions in Python?
- Put parens around the whole expression and separate clauses onto different lines
- Where to put boolean operators between clauses? at the end of the line or the beginning?
  - PEP8 recommends the beginning
```
if (expression1
and expression2
and expression3):
...
```
- Naming sub-expressions with variables
  - Odd downside that wouldn’t occur to me. All expressions are evaluated, thus not taking advantage of expression short-circuiting.
- Naming operations with functions
  - Less readable, but takes advantage of short-circuiting
- Using De Morgan’s Law : replacing a compound expression with a similar (and hopefully easier to read) expression
```
# neither: we want both to be false
not (a or b) == (not a) and (not b)

# never_both: at least one false
not (a and b) == (not a) or (not b)
```

Michael #4: fastapi-ml-skeleton

FastAPI Skeleton App to serve machine learning models production-ready.
This repository contains a skeleton app which can be used to speed-up your next machine learning project.
The code is fully tested and provides a preconfigured tox to quickly expand this sample code.
A sample regression model for house price prediction is included in this project.
Short write up on "What does set -a do?"

Extras

Brian:

OCF

Michael:

via Wei Lee

Extra Airflow ruff rules:

Starting from Ruff version 0.11.13, most changes from Airflow 2 to Airflow 3 can be automated using AIR3. (It’s still in preview so a “—-preview” flag is needed)

e.g., if you have the following Airflow 2 code

import datetime

from airflow.models import DAG
from airflow.operators.empty import EmptyOperator

with DAG(
  dag_id="my_dag_name",
  start_date=datetime.datetime(2021, 1, 1),
  schedule_interval="@daily",
):
EmptyOperator(task_id="task")

it can be fixed with uvx ruff check --select AIR3 --fix --unsafe-fixes --preview

import datetime

from airflow.sdk import DAG
from airflow.providers.standard.operators.empty import EmptyOperator

with DAG(
  dag_id="my_dag_name",
  start_date=datetime.datetime(2021, 1, 1),
  schedule="@daily",
):
EmptyOperator(task_id="task")

which works with Airflow 3.

Joke:

Front Toward Enemy

#439 That Astral Episode

Python Bytes