that-depends 1.9.2

Simple Dependency Injection framework

"That Depends"

This package is dependency injection framework for Python, mostly inspired by python-dependency-injector.

📚 Documentation

It is production-ready and gives you the following:

• Simple async-first DI framework with IOC-container.
• Python 3.10-3.12 support.
• Full coverage by types annotations (mypy in strict mode).
• FastAPI and Litestar compatibility.
• Overriding dependencies for tests.
• Injecting dependencies in async and sync functions and coroutines.
• Zero dependencies.

Projects with That Depends:

• fastapi-sqlalchemy-template - FastAPI template with sqlalchemy2 and PostgreSQL
• litestar-sqlalchemy-template - LiteStar template with sqlalchemy2 and PostgreSQL

Main decisions:

1. async-first means that by default, dependency resolving is async:

some_dependency = await DIContainer.dependent_factory()

2. Sync resolving is also possible, but will fail in case of async dependencies:

sync_resource = DIContainer.sync_resource.sync_resolve()  # this will work
async_resource = DIContainer.async_resource.sync_resolve()  # this will fail with RuntimeError

# but this will work
async_resource = await DIContainer.async_resource()
async_resource = DIContainer.async_resource.sync_resolve()

# and this will work
async_resource = await DIContainer.init_async_resources()
async_resource = DIContainer.async_resource.sync_resolve()

3. No wiring for injections in function arguments -> achieved by decision that only one instance of container is supported

from tests import container
from that_depends import Provide, inject, inject_to_sync

@inject
async def some_coroutine(
    simple_factory: container.SimpleFactory = Provide[container.DIContainer.simple_factory],
) -> None:
    assert simple_factory.dep1

@inject_to_sync
def some_sync_function(
    simple_factory: container.SimpleFactory = Provide[container.DIContainer.simple_factory],
) -> None:
    assert simple_factory.dep1

Quickstart

Install

pip install that-depends