This one has frustrated me for a while.

It starts off with a REST API route. For example in fastAPI

@app.get("/")
def search_users(session: Session) -> list[User]:
    """Finds users optionally filter by user_id"""
    statement = select(User).order_by(User.name)
    return session.execute(statement).scalars().all()

Then we get asked …

Structural pattern matching is probably the coolest new syntax introduced to Python. Added in 3.10, it's been a few years now and more people are writing apps in 3.10* than any other version now.

Though even with the wide adoption of 3.10 and more people being exposed …

Introduction

I wrote about free-threading recently in How free are threads in Python now?. Where I found some unexpected difficulties parallelising my solution.

In the conclusion section I wrote:

I'm starting to think that the approach sub-interpreters is taking, with brand new concurrency primitives and shared memory data structures has …

Free-threaded Python (PEP-703) was released in October 2024. It enables true multi-threaded execution without the restriction of the GIL.

I previously covered this in Free Threaded Python With Asyncio, the example used there was selected because it very clearly demonstrates the performance increase, or moreover, the threads "running free".

But …

I've been doing advent of code again this year. There are two Python features I always rely on, iterators and pattern matching. Iterators allow for operations on each of its elements without allocating memory for a collection. Ever since pattern matching was introduced in Python 3.10, it's been particularly …

I've been experimenting with Langchain for GPT based queries. One problem we often encounter with GPT is hallucinations. This makes certain classes of problems unsuited to GPT, one example is maths and statistics. Whilst there are improvements for recent models often the maths cannot be trusted.

When I try to …

I've worked with SQLAlchemy for a while now, and in my opinion it's the best ORM in Python. It's feature rich with strong support for all major databases. And it maintains the SQL feel without losing things like typing.

However there are some challenges here. Despite having very nice documentation …

TypedDict was introduced in PEP-589 which landed in Python 3.8.

The primary use case was to create type annotations for dictionaries. For example,

class Movie(TypedDict):
    title: str


movie: Movie = {"title": "Avatar"}

I remember thinking at the time that this was pretty neat, but I tend to use dataclass …

I recently came across a video by mcoding about Python iterators' unfortunate closing behaviour.

To sum up the video, when an iterator is interrupted we intuitively we would expect the exit of a context manager or a finally block to be called but that's not necessarily the case. For example …

With the imminent release of Python 3.13, I wanted to look at the biggest changes coming to Python. I think by far the most exciting feature is free-threaded Python from PEP-703.

As I'm quite late to the party, there's already a lot of articles talking about it. I came …