================================================================= Dependency Injector --- Dependency injection framework for Python

.. meta:: :google-site-verification: V1hlKfpgL3AARAElwFcqP4qW1Smsx5bKSRU8O86i20Y :keywords: Python,Dependency injection,DI,Inversion of Control,IoC, IoC Container,Factory, Singleton, Design Patterns :description: Dependency Injector is a dependency injection framework for Python. It helps to maintain you application structure. It was designed to be unified, developer-friendly tool that helps to implement dependency injection design pattern in formal, pretty, Pythonic way. Dependency Injector provides implementations of such popular design patterns like IoC container, Factory and Singleton. Dependency Injector providers are implemented as C extension types using Cython.

.. _index:

.. image:: https://img.shields.io/pypi/v/dependency_injector.svg :target: https://pypi.org/project/dependency-injector/ :alt: Latest Version

.. image:: https://img.shields.io/pypi/l/dependency_injector.svg :target: https://pypi.org/project/dependency-injector/ :alt: License

.. image:: https://img.shields.io/pypi/pyversions/dependency_injector.svg :target: https://pypi.org/project/dependency-injector/ :alt: Supported Python versions

.. image:: https://img.shields.io/pypi/implementation/dependency_injector.svg :target: https://pypi.org/project/dependency-injector/ :alt: Supported Python implementations

.. image:: https://static.pepy.tech/badge/dependency-injector :target: https://pepy.tech/project/dependency-injector :alt: Downloads

.. image:: https://static.pepy.tech/badge/dependency-injector/month :target: https://pepy.tech/project/dependency-injector :alt: Downloads

.. image:: https://static.pepy.tech/badge/dependency-injector/week :target: https://pepy.tech/project/dependency-injector :alt: Downloads

.. image:: https://img.shields.io/pypi/wheel/dependency-injector.svg :target: https://pypi.org/project/dependency-injector/ :alt: Wheel

.. image:: https://img.shields.io/github/actions/workflow/status/ets-labs/python-dependency-injector/tests-and-linters.yml?branch=master :target: https://github.com/ets-labs/python-dependency-injector/actions :alt: Build Status

.. image:: https://coveralls.io/repos/github/ets-labs/python-dependency-injector/badge.svg?branch=master :target: https://coveralls.io/github/ets-labs/python-dependency-injector?branch=master :alt: Coverage Status

Dependency Injector is a dependency injection framework for Python.

It helps implementing the dependency injection principle.

Key features of the Dependency Injector:

Providers. Provides Factory, Singleton, Callable, Coroutine, Object, List, Dict, Configuration, Resource, Dependency, and Selector providers that help assemble your objects. See :ref:providers.
Overriding. Can override any provider by another provider on the fly. This helps in testing and configuring dev/stage environment to replace API clients with stubs etc. See :ref:provider-overriding.
Configuration. Reads configuration from yaml, ini, and json files, pydantic settings, environment variables, and dictionaries. See :ref:configuration-provider.
Resources. Helps with initialization and configuring of logging, event loop, thread or process pool, etc. Can be used for per-function execution scope in tandem with wiring. See :ref:resource-provider.
Containers. Provides declarative and dynamic containers. See :ref:containers.
Wiring. Injects dependencies into functions and methods. Helps integrate with other frameworks: Django, Flask, Aiohttp, Sanic, FastAPI, etc. See :ref:wiring.
Asynchronous. Supports asynchronous injections. See :ref:async-injections.
Typing. Provides typing stubs, mypy-friendly. See :ref:provider-typing.
Performance. Fast. Written in Cython.
Maturity. Mature and production-ready. Well-tested, documented, and supported.

.. code-block:: python

from dependency_injector import containers, providers from dependency_injector.wiring import Provide, inject

class Container(containers.DeclarativeContainer):

   config = providers.Configuration()

   api_client = providers.Singleton(
       ApiClient,
       api_key=config.api_key,
       timeout=config.timeout,
   )

   service = providers.Factory(
       Service,
       api_client=api_client,
   )

@inject def main(service: Service = Provide[Container.service]) -> None: ...

if name == "main": container = Container() container.config.api_key.from_env("API_KEY", required=True) container.config.timeout.from_env("TIMEOUT", as_=int, default=5) container.wire(modules=[name])

   main()  # <-- dependency is injected automatically

   with container.api_client.override(mock.Mock()):
       main()  # <-- overridden dependency is injected automatically

With the Dependency Injector, object assembling is consolidated in the container. Dependency injections are defined explicitly. This makes it easier to understand and change how the application works.

.. figure:: https://raw.githubusercontent.com/wiki/ets-labs/python-dependency-injector/img/di-readme.svg :target: https://github.com/ets-labs/python-dependency-injector

Explore the documentation to know more about the Dependency Injector.

.. _contents:

.. toctree:: :maxdepth: 2

introduction/index examples/index tutorials/index providers/index containers/index wiring examples-other/index api/index main/feedback main/changelog

================================================================= Dependency Injector --- Dependency injection framework for Python

Contents