.. _fastdepends-example:

FastDepends example
===================

.. meta::
   :keywords: Python,Dependency Injection,FastDepends,Example
   :description: This example demonstrates a usage of the FastDepends and Dependency Injector.


This example shows how to use ``Dependency Injector`` with `FastDepends <https://github.com/Lancetnik/FastDepends>`_.

Example code is available on `Github <https://github.com/ets-labs/python-dependency-injector/tree/master/tests/unit/wiringfastdepends>`_.

Quick sample
------------

Just use it within ``Depends``

.. code-block:: python

    import sys

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


    class CoefficientService:
        @staticmethod
        def get_coefficient() -> float:
            return 1.2


    class Container(containers.DeclarativeContainer):
        service = providers.Factory(CoefficientService)


    @inject
    def apply_coefficient(
        a: int,
        coefficient_provider: CoefficientService = Depends(Provide[Container.service]),
    ) -> float:
        return a * coefficient_provider.get_coefficient()


    container = Container()
    container.wire(modules=[sys.modules[__name__]])

    apply_coefficient(100) == 120.0