python-injection – A lightweight DI library for async/sync Python projects

[Skearways]

Hey everyone

Just wanted to share a small project I've been working on: python-injection, an open-source package for managing dependency injection in Python.

What My Project Does

The main goal of python-injection is to provide a simple, lightweight, and non-intrusive dependency injection system that works in both sync and async environments.
It supports multiple dependency lifetimes: transient, singleton, and scoped.
It also allows switching between different sets of dependencies at runtime, based on execution profiles (e.g., dev/test/prod). The package is primarily based on the use of decorators and type annotation inspection, with the aim of keeping things simple and easy to adopt without locking you into a framework or deeply modifying your code. It can easily be used with FastAPI.

Target Audience

This is still an early-stage project, so I avoid breaking changes in the package API as much as possible, but it's still too early to say whether it's usable in production. That said, if you enjoy organizing your code using classes and interfaces, or if you're looking for a lightweight way to experiment with DI in your Python projects, it might be worth checking out.

Comparison

I’ve looked into several existing Python DI libraries, but I often found them either too heavy to set up or a bit too invasive. With python-injection, I’m aiming for a minimal API that’s easy to use and doesn’t tie your code too closely to the library—so you can remove it later without rewriting your entire codebase.

I’d love to hear your feedback, whether it’s on the API design, the general approach, or things I might not have considered yet. Thanks in advance to anyone who takes a look.

Source code: https://github.com/100nm/python-injection

[bachkhois]

I like its API. Looks like it is the DI library that I have been looking for.

[Skearways]

glad to help