Overview

Linkd is a powerful dependency-injection framework for asyncio-based Python applications.

This library aims to provide an easy way for framework developers to provide dependency-injection functionality, while also being suitable for use with standalone applications with a little bit more work.

For an example of linkd in action, have a look at hikari-lightbulb which uses it to provide all dependency injection functionality.

Installation

Use the package manager pip to install linkd.

pip install linkd

Usage

Standalone

The most basic usage of linkd involves three main steps:

• Creating a DependencyInjectionManager and registering dependencies
• Setting up an injection context
• Enabling injection on a function

An example of all the above can be seen below:

import asyncio

import linkd

# create a manager instance
manager = linkd.DependencyInjectionManager()
# register a dependency to one of the manager's registries
manager.registry_for(linkd.Contexts.ROOT).register_value(str, "thomm.o")

# enable injection on a function with the inject decorator
@linkd.inject
async def greet(who: str) -> str:
    # the 'who' parameter will be injected by linkd
    return f"hello {who}"


# use the contextual decorator to automatically set up an injection context
@manager.contextual(linkd.Contexts.ROOT)
async def main() -> None:
    # call the injected method
    print(await greet())


if __name__ == "__main__":
    asyncio.run(main())

Supported Framework

Linkd currently supports the following frameworks (click to jump to example usage):

• FastAPI
• Quart
• Starlette
• gRPC (example pending)
• ConnectRPC (example pending)

If your framework isn't mentioned here, feel free to open an issue requesting support!

Issues

If you find any bugs, issues, or unexpected behaviour while using the library, you should open an issue with details of the problem and how to reproduce if possible. Please also open an issue for any new features you would like to see added.

Contributing

Pull requests are welcome. For major changes, please open an issue/discussion first to discuss what you would like to change.

Please try to ensure that documentation is updated if you add any features accessible through the public API.

If you use this library and like it, feel free to sign up to GitHub and star the project, it is greatly appreciated and lets me know that I'm going in the right direction!

Links

• License: MIT
• Repository: GitHub
• Documentation: ReadTheDocs