python-dependency-injector/examples/providers/factory_init_injections_underlying.py

"""`Factory` provider - passing injections to the underlying providers example."""

from dependency_injector import containers, providers


class Regularizer:
    def __init__(self, alpha: float) -> None:
        self.alpha = alpha


class Loss:
    def __init__(self, regularizer: Regularizer) -> None:
        self.regularizer = regularizer


class ClassificationTask:
    def __init__(self, loss: Loss) -> None:
        self.loss = loss


class Algorithm:
    def __init__(self, task: ClassificationTask) -> None:
        self.task = task


class Container(containers.DeclarativeContainer):

    algorithm_factory = providers.Factory(
        Algorithm,
        task=providers.Factory(
            ClassificationTask,
            loss=providers.Factory(
                Loss,
                regularizer=providers.Factory(
                    Regularizer,
                ),
            ),
        ),
    )


if __name__ == "__main__":
    container = Container()

    algorithm_1 = container.algorithm_factory(
        task__loss__regularizer__alpha=0.5,
    )
    assert algorithm_1.task.loss.regularizer.alpha == 0.5

    algorithm_2 = container.algorithm_factory(
        task__loss__regularizer__alpha=0.7,
    )
    assert algorithm_2.task.loss.regularizer.alpha == 0.7