Add example

examples/providers/factory_deep_init_injections.py

@@ -0,0 +1,48 @@
+"""`Factory` providers deep init injections example."""
+
+from dependency_injector import providers
+
+
+class Regularizer:
+    def __init__(self, alpha):
+        self.alpha = alpha
+
+
+class Loss:
+    def __init__(self, regularizer):
+        self.regularizer = regularizer
+
+
+class ClassificationTask:
+    def __init__(self, loss):
+        self.loss = loss
+
+
+class Algorithm:
+    def __init__(self, task):
+        self.task = task
+
+
+algorithm_factory = providers.Factory(
+    Algorithm,
+    task=providers.Factory(
+        ClassificationTask,
+        loss=providers.Factory(
+            Loss,
+            regularizer=providers.Factory(
+                Regularizer,
+            ),
+        ),
+    ),
+)
+
+
+if __name__ == '__main__':
+    algorithm_1 = algorithm_factory(task__loss__regularizer__alpha=0.5)
+    assert algorithm_1.task.loss.regularizer.alpha == 0.5
+
+    algorithm_2 = algorithm_factory(task__loss__regularizer__alpha=0.7)
+    assert algorithm_2.task.loss.regularizer.alpha == 0.7
+
+    algorithm_3 = algorithm_factory(task__loss__regularizer=Regularizer(alpha=0.8))
+    assert algorithm_3.task.loss.regularizer.alpha == 0.8