Merge branch 'release/4.38.0' into master

README.rst

@@ -90,7 +90,7 @@ Key features of the ``Dependency Injector``:
        api_client = providers.Singleton(
            ApiClient,
            api_key=config.api_key,
-           timeout=config.timeout.as_int(),
+           timeout=config.timeout,
        )
 
        service = providers.Factory(
@@ -106,8 +106,8 @@ Key features of the ``Dependency Injector``:
 
    if __name__ == "__main__":
        container = Container()
-       container.config.api_key.from_env("API_KEY")
-       container.config.timeout.from_env("TIMEOUT")
+       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

docs/index.rst

@@ -96,7 +96,7 @@ Key features of the ``Dependency Injector``:
        api_client = providers.Singleton(
            ApiClient,
            api_key=config.api_key,
-           timeout=config.timeout.as_int(),
+           timeout=config.timeout,
        )
 
        service = providers.Factory(
@@ -112,8 +112,8 @@ Key features of the ``Dependency Injector``:
 
    if __name__ == "__main__":
        container = Container()
-       container.config.api_key.from_env("API_KEY")
-       container.config.timeout.from_env("TIMEOUT")
+       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

docs/introduction/di_in_python.rst

@@ -150,7 +150,7 @@ What does the Dependency Injector do?
 -------------------------------------
 
 With the dependency injection pattern objects loose the responsibility of assembling
-the dependencies. The ``Dependency Injector`` absorbs that responsibilities.
+the dependencies. The ``Dependency Injector`` absorbs that responsibility.
 
 ``Dependency Injector`` helps to assemble and inject the dependencies.
 
@@ -172,7 +172,7 @@ the dependency.
        api_client = providers.Singleton(
            ApiClient,
            api_key=config.api_key,
-           timeout=config.timeout.as_int(),
+           timeout=config.timeout,
        )
 
        service = providers.Factory(
@@ -188,8 +188,8 @@ the dependency.
 
    if __name__ == "__main__":
        container = Container()
-       container.config.api_key.from_env("API_KEY")
-       container.config.timeout.from_env("TIMEOUT")
+       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

docs/main/changelog.rst

@@ -7,6 +7,31 @@ that were made in every particular version.
 From version 0.7.6 *Dependency Injector* framework strictly 
 follows `Semantic versioning`_
 
+4.38.0
+------
+- Add new provider ``Aggregate``. It is a generalized version of ``FactoryAggregate`` that
+  can contain providers of any type, not only ``Factory``. See issue
+  `#530 <https://github.com/ets-labs/python-dependency-injector/issues/530>`_. Thanks to
+  `@zerlok (Danil Troshnev) <https://github.com/zerlok>`_ for suggesting the feature.
+- Add argument ``as_`` to the ``config.from_env()`` method for the explicit type casting
+  of an environment variable value, e.g.: ``config.timeout.from_env("TIMEOUT", as_=int)``.
+  See issue `#533 <https://github.com/ets-labs/python-dependency-injector/issues/533>`_. Thanks to
+  `@gtors (Andrey Torsunov) <https://github.com/gtors>`_ for suggesting the feature.
+- Add ``.providers`` attribute to the ``FactoryAggregate`` provider. It is an alias for
+  ``FactoryAggregate.factories`` attribute.
+- Add ``.set_providers()`` method to the ``FactoryAggregate`` provider. It is an alias for
+  ``FactoryAggregate.set_factories()`` method.
+- Add string imports for ``Factory``, ``Singleton``, ``Callable``, ``Resource``, and ``Coroutine``
+  providers, e.g. ``Factory("module.Class")``.
+  See issue `#531 <https://github.com/ets-labs/python-dependency-injector/issues/531>`_.
+  Thanks to `@al-stefanitsky-mozdor <https://github.com/al-stefanitsky-mozdor>`_ for suggesting the feature.
+- Fix ``Dependency`` provider to don't raise "Dependency is not defined" error when the ``default``
+  is a falsy value of proper type.
+  See issue `#550 <https://github.com/ets-labs/python-dependency-injector/issues/550>`_. Thanks to
+  `@approxit <https://github.com/approxit>`_ for reporting the issue.
+- Refactor ``FactoryAggregate`` provider internals.
+- Update logo on Github and in docs to support dark themes and remove some imperfections.
+
 4.37.0
 ------
 - Add support of Python 3.10.

docs/providers/aggregate.rst

@@ -0,0 +1,72 @@
+.. _aggregate-provider:
+
+Aggregate provider
+==================
+
+.. meta::
+   :keywords: Python,DI,Dependency injection,IoC,Inversion of Control,Configuration,Injection,
+              Aggregate,Polymorphism,Environment Variable,Flexibility
+   :description: Aggregate provider aggregates other providers.
+                 This page demonstrates how to implement the polymorphism and increase the
+                 flexibility of your application using the Aggregate provider.
+
+:py:class:`Aggregate` provider aggregates a group of other providers.
+
+.. currentmodule:: dependency_injector.providers
+
+.. literalinclude:: ../../examples/providers/aggregate.py
+   :language: python
+   :lines: 3-
+   :emphasize-lines: 24-27
+
+Each provider in the ``Aggregate`` is associated with a key. You can call aggregated providers by providing
+their key as a first argument. All positional and keyword arguments following the key will be forwarded to
+the called provider:
+
+.. code-block:: python
+
+   yaml_reader = container.config_readers("yaml", "./config.yml", foo=...)
+
+You can also retrieve an aggregated provider by providing its key as an attribute name:
+
+.. code-block:: python
+
+   yaml_reader = container.config_readers.yaml("./config.yml", foo=...)
+
+To retrieve a dictionary of aggregated providers, use ``.providers`` attribute:
+
+.. code-block:: python
+
+   container.config_readers.providers == {
+       "yaml": <YAML provider>,
+       "json": <JSON provider>,
+   }
+
+.. note::
+   You can not override the ``Aggregate`` provider.
+
+.. note::
+   When you inject the ``Aggregate`` provider, it is passed "as is".
+
+To use non-string keys or string keys with ``.`` and ``-``, provide a dictionary as a positional argument:
+
+.. code-block:: python
+
+   aggregate = providers.Aggregate({
+       SomeClass: providers.Factory(...),
+       "key.with.periods": providers.Factory(...),
+       "key-with-dashes": providers.Factory(...),
+   })
+
+.. seealso::
+   :ref:`selector-provider` to make injections based on a configuration value, environment variable, or a result of a callable.
+
+   ``Aggregate`` provider is different from the :ref:`selector-provider`. ``Aggregate`` provider doesn't select which provider
+   to inject and doesn't have a selector. It is a group of providers and is always injected "as is". The rest of the interface
+   of both providers is similar.
+
+.. note::
+   ``Aggregate`` provider is a successor of :ref:`factory-aggregate-provider` provider. ``Aggregate`` provider doesn't have
+   a restriction on the provider type, while ``FactoryAggregate`` aggregates only ``Factory`` providers.
+
+.. disqus::

docs/providers/configuration.rst

@@ -205,6 +205,24 @@ Loading from an environment variable
    :lines: 3-
    :emphasize-lines: 18-20
 
+You can use ``as_`` argument for the type casting of an environment variable value:
+
+.. code-block:: python
+   :emphasize-lines: 2,6,10
+
+   # API_KEY=secret
+   container.config.api_key.from_env("API_KEY", as_=str, required=True)
+   assert container.config.api_key() == "secret"
+
+   # SAMPLING_RATIO=0.5
+   container.config.sampling.from_env("SAMPLING_RATIO", as_=float, required=True)
+   assert container.config.sampling() == 0.5
+
+   # TIMEOUT undefined, default is used
+   container.config.timeout.from_env("TIMEOUT", as_=int, default=5)
+   assert container.config.timeout() == 5
+
+
 Loading a value
 ---------------
 

docs/providers/factory.rst

@@ -110,6 +110,45 @@ attribute of the provider that you're going to inject.
 
 .. note:: Any provider has a ``.provider`` attribute.
 
+.. _factory-string-imports:
+
+String imports
+--------------
+
+``Factory`` provider can handle string imports:
+
+.. code-block:: python
+
+   class Container(containers.DeclarativeContainer):
+
+       service = providers.Factory("myapp.mypackage.mymodule.Service")
+
+You can also make a relative import:
+
+.. code-block:: python
+
+   # in myapp/container.py
+
+   class Container(containers.DeclarativeContainer):
+
+       service = providers.Factory(".mypackage.mymodule.Service")
+
+or import a member of the current module just specifying its name:
+
+.. code-block:: python
+
+   class Service:
+       ...
+
+
+   class Container(containers.DeclarativeContainer):
+
+       service = providers.Factory("Service")
+
+.. note::
+   ``Singleton``, ``Callable``, ``Resource``, and ``Coroutine`` providers handle string imports
+   the same way as a ``Factory`` provider.
+
 .. _factory-specialize-provided-type:
 
 Specializing the provided type
@@ -145,11 +184,17 @@ provider with two peculiarities:
    :lines: 3-
    :emphasize-lines: 34
 
+.. _factory-aggregate-provider:
+
 Factory aggregate
 -----------------
 
 :py:class:`FactoryAggregate` provider aggregates multiple factories.
 
+.. seealso::
+   :ref:`aggregate-provider` – it's a successor of ``FactoryAggregate`` provider that can aggregate
+   any type of provider, not only ``Factory``.
+
 The aggregated factories are associated with the string keys. When you call the
 ``FactoryAggregate`` you have to provide one of the these keys as a first argument.
 ``FactoryAggregate`` looks for the factory with a matching key and calls it with the rest of the arguments.
@@ -163,9 +208,9 @@ The aggregated factories are associated with the string keys. When you call the
    :lines: 3-
    :emphasize-lines: 33-37,47
 
-You can get a dictionary of the aggregated factories using the ``.factories`` attribute.
-To get a game factories dictionary from the previous example you can use
-``game_factory.factories`` attribute.
+You can get a dictionary of the aggregated providers using ``.providers`` attribute.
+To get a game provider dictionary from the previous example you can use
+``game_factory.providers`` attribute.
 
 You can also access an aggregated factory as an attribute. To create the ``Chess`` object from the
 previous example you can do ``chess = game_factory.chess("John", "Jane")``.
@@ -176,7 +221,7 @@ previous example you can do ``chess = game_factory.chess("John", "Jane")``.
 .. note::
    When you inject the ``FactoryAggregate`` provider it is passed "as is".
 
-To use non-string keys or keys with ``.`` and ``-`` you can provide a dictionary as a positional argument:
+To use non-string keys or string keys with ``.`` and ``-``, you can provide a dictionary as a positional argument:
 
 .. code-block:: python
 

docs/providers/index.rst

@@ -46,6 +46,7 @@ Providers module API docs - :py:mod:`dependency_injector.providers`
     dict
     configuration
     resource
+    aggregate
     selector
     dependency
     overriding

docs/providers/selector.rst

@@ -30,4 +30,7 @@ When a ``Selector`` provider is called, it gets a ``selector`` value and delegat
 the provider with a matching name. The ``selector`` callable works as a switch: when the returned
 value is changed the ``Selector`` provider will delegate the work to another provider.
 
+.. seealso::
+   :ref:`aggregate-provider` to inject a group of providers.
+
 .. disqus::

examples/demo/with_di.py

@@ -13,7 +13,7 @@ class Container(containers.DeclarativeContainer):
     api_client = providers.Singleton(
         ApiClient,
         api_key=config.api_key,
-        timeout=config.timeout.as_int(),
+        timeout=config.timeout,
     )
 
     service = providers.Factory(
@@ -29,8 +29,8 @@ def main(service: Service = Provide[Container.service]):
 
 if __name__ == "__main__":
     container = Container()
-    container.config.api_key.from_env("API_KEY")
-    container.config.timeout.from_env("TIMEOUT")
+    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

examples/providers/aggregate.py

@@ -0,0 +1,39 @@
+"""`Aggregate` provider example."""
+
+from dependency_injector import containers, providers
+
+
+class ConfigReader:
+
+    def __init__(self, path):
+        self._path = path
+
+    def read(self):
+        print(f"Parsing {self._path} with {self.__class__.__name__}")
+        ...
+
+
+class YamlReader(ConfigReader):
+    ...
+
+
+class JsonReader(ConfigReader):
+    ...
+
+
+class Container(containers.DeclarativeContainer):
+
+    config_readers = providers.Aggregate(
+        yaml=providers.Factory(YamlReader),
+        json=providers.Factory(JsonReader),
+    )
+
+
+if __name__ == "__main__":
+    container = Container()
+
+    yaml_reader = container.config_readers("yaml", "./config.yml")
+    yaml_reader.read()  # Parsing ./config.yml with YamlReader
+
+    json_reader = container.config_readers("json", "./config.json")
+    json_reader.read()  # Parsing ./config.json with JsonReader

src/dependency_injector/__init__.py

@@ -1,6 +1,6 @@
 """Top-level package."""
 
-__version__ = "4.37.0"
+__version__ = "4.38.0"
 """Version number.
 
 :type: str

src/dependency_injector/containers.pyi

@@ -20,11 +20,11 @@ from typing import (
 from .providers import Provider, Self, ProviderParent
 
 
-C_Base = TypeVar('C_Base', bound='Container')
-C = TypeVar('C', bound='DeclarativeContainer')
-C_Overriding = TypeVar('C_Overriding', bound='DeclarativeContainer')
-T = TypeVar('T')
-TT = TypeVar('TT')
+C_Base = TypeVar("C_Base", bound="Container")
+C = TypeVar("C", bound="DeclarativeContainer")
+C_Overriding = TypeVar("C_Overriding", bound="DeclarativeContainer")
+T = TypeVar("T")
+TT = TypeVar("TT")
 
 
 class WiringConfiguration:

src/dependency_injector/containers.pyx

@@ -28,10 +28,10 @@ if sys.version_info[:2] >= (3, 6):
     from .wiring import wire, unwire
 else:
     def wire(*args, **kwargs):
-        raise NotImplementedError('Wiring requires Python 3.6 or above')
+        raise NotImplementedError("Wiring requires Python 3.6 or above")
 
     def unwire(*args, **kwargs):
-        raise NotImplementedError('Wiring requires Python 3.6 or above')
+        raise NotImplementedError("Wiring requires Python 3.6 or above")
 
 if sys.version_info[:2] == (3, 5):
     warnings.warn(
@@ -137,17 +137,17 @@ class DynamicContainer(Container):
         If value of attribute is provider, it will be added into providers
         dictionary.
 
-        :param name: Attribute's name
+        :param name: Attribute name
         :type name: object
 
-        :param value: Attribute's value
+        :param value: Attribute value
         :type value: object
 
         :rtype: None
         """
         if isinstance(value, providers.Provider) \
                 and not isinstance(value, providers.Self) \
-                and name != 'parent':
+                and name != "parent":
             _check_provider_type(self, value)
 
             self.providers[name] = value
@@ -163,7 +163,7 @@ class DynamicContainer(Container):
         If value of attribute is provider, it will be deleted from providers
         dictionary.
 
-        :param name: Attribute's name
+        :param name: Attribute name
         :type name: object
 
         :rtype: None
@@ -229,8 +229,8 @@ class DynamicContainer(Container):
         :rtype: None
         """
         if overriding is self:
-            raise errors.Error('Container {0} could not be overridden '
-                               'with itself'.format(self))
+            raise errors.Error("Container {0} could not be overridden "
+                               "with itself".format(self))
 
         self.overridden += (overriding,)
 
@@ -262,7 +262,7 @@ class DynamicContainer(Container):
         :rtype: None
         """
         if not self.overridden:
-            raise errors.Error('Container {0} is not overridden'.format(self))
+            raise errors.Error("Container {0} is not overridden".format(self))
 
         self.overridden = self.overridden[:-1]
 
@@ -364,7 +364,7 @@ class DynamicContainer(Container):
             while any(resource.initialized for resource in resources):
                 resources_to_shutdown = list(_independent_resources(resources))
                 if not resources_to_shutdown:
-                    raise RuntimeError('Unable to resolve resources shutdown order')
+                    raise RuntimeError("Unable to resolve resources shutdown order")
                 futures = []
                 for resource in resources_to_shutdown:
                     result = resource.shutdown()
@@ -376,7 +376,7 @@ class DynamicContainer(Container):
             while any(resource.initialized for resource in resources):
                 resources_to_shutdown = list(_independent_resources(resources))
                 if not resources_to_shutdown:
-                    raise RuntimeError('Unable to resolve resources shutdown order')
+                    raise RuntimeError("Unable to resolve resources shutdown order")
                 for resource in resources_to_shutdown:
                     resource.shutdown()
 
@@ -393,7 +393,7 @@ class DynamicContainer(Container):
             config.load()
 
     def apply_container_providers_overridings(self):
-        """Apply container providers' overridings."""
+        """Apply container providers overridings."""
         for provider in self.traverse(types=[providers.Container]):
             provider.apply_overridings()
 
@@ -419,12 +419,12 @@ class DynamicContainer(Container):
 
         container_name = self.parent_name if self.parent_name else self.__class__.__name__
         undefined_names = [
-            f'"{dependency.parent_name if dependency.parent_name else dependency}"'
+            f"\"{dependency.parent_name if dependency.parent_name else dependency}\""
             for dependency in undefined
         ]
         raise errors.Error(
-            f'Container "{container_name}" has undefined dependencies: '
-            f'{", ".join(undefined_names)}',
+            f"Container \"{container_name}\" has undefined dependencies: "
+            f"{', '.join(undefined_names)}",
         )
 
     def from_schema(self, schema):
@@ -441,9 +441,9 @@ class DynamicContainer(Container):
         """
         if yaml is None:
             raise errors.Error(
-                'Unable to load yaml schema - PyYAML is not installed. '
-                'Install PyYAML or install Dependency Injector with yaml extras: '
-                '"pip install dependency-injector[yaml]"'
+                "Unable to load yaml schema - PyYAML is not installed. "
+                "Install PyYAML or install Dependency Injector with yaml extras: "
+                "\"pip install dependency-injector[yaml]\""
             )
 
         if loader is None:
@@ -466,7 +466,7 @@ class DynamicContainer(Container):
             if container_provider is provider:
                 return provider_name
         else:
-            raise errors.Error(f'Can not resolve name for provider "{provider}"')
+            raise errors.Error(f"Can not resolve name for provider \"{provider}\"")
 
     @property
     def parent_name(self):
@@ -525,11 +525,11 @@ class DeclarativeContainerMetaClass(type):
                 "instead got {0}".format(wiring_config)
             )
 
-        attributes['containers'] = containers
-        attributes['inherited_providers'] = inherited_providers
-        attributes['cls_providers'] = cls_providers
-        attributes['providers'] = all_providers
-        attributes['wiring_config'] = wiring_config
+        attributes["containers"] = containers
+        attributes["inherited_providers"] = inherited_providers
+        attributes["cls_providers"] = cls_providers
+        attributes["providers"] = all_providers
+        attributes["wiring_config"] = wiring_config
 
         cls = <type>type.__new__(mcs, class_name, bases, attributes)
 
@@ -551,15 +551,15 @@ class DeclarativeContainerMetaClass(type):
         If value of attribute is provider, it will be added into providers
         dictionary.
 
-        :param name: Attribute's name
+        :param name: Attribute name
         :type name: object
 
-        :param value: Attribute's value
+        :param value: Attribute value
         :type value: object
 
         :rtype: None
         """
-        if isinstance(value, providers.Provider) and name != '__self__':
+        if isinstance(value, providers.Provider) and name != "__self__":
             _check_provider_type(cls, value)
 
             if isinstance(value, providers.CHILD_PROVIDERS):
@@ -575,7 +575,7 @@ class DeclarativeContainerMetaClass(type):
         If value of attribute is provider, it will be deleted from providers
         dictionary.
 
-        :param name: Attribute's name
+        :param name: Attribute name
         :type name: object
 
         :rtype: None
@@ -611,7 +611,7 @@ class DeclarativeContainerMetaClass(type):
             if container_provider is provider:
                 return provider_name
         else:
-            raise errors.Error(f'Can not resolve name for provider "{provider}"')
+            raise errors.Error(f"Can not resolve name for provider \"{provider}\"")
 
     @property
     def parent_name(cls):
@@ -628,9 +628,9 @@ class DeclarativeContainerMetaClass(type):
                 continue
 
             if self is not None and value is not self:
-                raise errors.Error('Container can have only one "Self" provider')
+                raise errors.Error("Container can have only one \"Self\" provider")
 
-            if name != '__self__':
+            if name != "__self__":
                 alt_names.append(name)
 
             self = value
@@ -727,8 +727,8 @@ class DeclarativeContainer(Container):
         container.wiring_config = copy_module.deepcopy(cls.wiring_config)
         container.declarative_parent = cls
 
-        copied_providers = providers.deepcopy({ **cls.providers, **{'@@self@@': cls.__self__}})
-        copied_self = copied_providers.pop('@@self@@')
+        copied_providers = providers.deepcopy({ **cls.providers, **{"@@self@@": cls.__self__}})
+        copied_self = copied_providers.pop("@@self@@")
         copied_self.set_container(container)
 
         container.__self__ = copied_self
@@ -762,8 +762,8 @@ class DeclarativeContainer(Container):
         :rtype: None
         """
         if issubclass(cls, overriding):
-            raise errors.Error('Container {0} could not be overridden '
-                               'with itself or its subclasses'.format(cls))
+            raise errors.Error("Container {0} could not be overridden "
+                               "with itself or its subclasses".format(cls))
 
         cls.overridden += (overriding,)
 
@@ -780,7 +780,7 @@ class DeclarativeContainer(Container):
         :rtype: None
         """
         if not cls.overridden:
-            raise errors.Error('Container {0} is not overridden'.format(cls))
+            raise errors.Error("Container {0} is not overridden".format(cls))
 
         cls.overridden = cls.overridden[:-1]
 
@@ -833,7 +833,7 @@ def override(object container):
                       container.
     :type container: :py:class:`DeclarativeContainer`
 
-    :return: Declarative container's overriding decorator.
+    :return: Declarative container overriding decorator.
     :rtype: callable(:py:class:`DeclarativeContainer`)
     """
     def _decorator(object overriding_container):
@@ -853,7 +853,7 @@ def copy(object base_container):
     :param base_container: Container that should be copied by decorated container.
     :type base_container: :py:class:`DeclarativeContainer`
 
-    :return: Declarative container's copying decorator.
+    :return: Declarative container copying decorator.
     :rtype: callable(:py:class:`DeclarativeContainer`)
     """
     def _get_memo_for_matching_names(new_providers, base_providers):
@@ -864,7 +864,7 @@ def copy(object base_container):
             source_provider = base_providers[new_provider_name]
             memo[id(source_provider)] = new_provider
 
-            if hasattr(new_provider, 'providers') and hasattr(source_provider, 'providers'):
+            if hasattr(new_provider, "providers") and hasattr(source_provider, "providers"):
                 sub_memo = _get_memo_for_matching_names(new_provider.providers, source_provider.providers)
                 memo.update(sub_memo)
         return memo
@@ -892,13 +892,13 @@ cpdef bint is_container(object instance):
 
     :rtype: bool
     """
-    return getattr(instance, '__IS_CONTAINER__', False) is True
+    return getattr(instance, "__IS_CONTAINER__", False) is True
 
 
 cpdef object _check_provider_type(object container, object provider):
     if not isinstance(provider, container.provider_type):
-        raise errors.Error('{0} can contain only {1} '
-                           'instances'.format(container, container.provider_type))
+        raise errors.Error("{0} can contain only {1} "
+                           "instances".format(container, container.provider_type))
 
 
 cpdef bint _any_relative_string_imports_in(object modules):

src/dependency_injector/providers.pxd

@@ -38,6 +38,12 @@ cdef class Delegate(Provider):
     cpdef object _provide(self, tuple args, dict kwargs)
 
 
+cdef class Aggregate(Provider):
+    cdef dict __providers
+
+    cdef Provider __get_provider(self, object provider_name)
+
+
 cdef class Dependency(Provider):
     cdef object __instance_of
     cdef object __default
@@ -142,10 +148,8 @@ cdef class FactoryDelegate(Delegate):
     pass
 
 
-cdef class FactoryAggregate(Provider):
-    cdef dict __factories
-
-    cdef Factory __get_factory(self, object factory_name)
+cdef class FactoryAggregate(Aggregate):
+    pass
 
 
 # Singleton providers
@@ -359,11 +363,11 @@ cdef inline tuple __separate_prefixed_kwargs(dict kwargs):
     cdef dict prefixed_kwargs = {}
 
     for key, value in kwargs.items():
-        if '__' not in key:
+        if "__" not in key:
             plain_kwargs[key] = value
             continue
 
-        index = key.index('__')
+        index = key.index("__")
         prefix, name = key[:index], key[index+2:]
 
         if prefix not in prefixed_kwargs:

src/dependency_injector/providers.pyi

@@ -35,11 +35,11 @@ from . import resources
 
 
 Injection = Any
-ProviderParent = Union['Provider', Any]
-T = TypeVar('T')
-TT = TypeVar('TT')
-P = TypeVar('P', bound='Provider')
-BS = TypeVar('BS', bound='BaseSingleton')
+ProviderParent = Union["Provider", Any]
+T = TypeVar("T")
+TT = TypeVar("TT")
+P = TypeVar("P", bound="Provider")
+BS = TypeVar("BS", bound="BaseSingleton")
 
 
 class Provider(Generic[T]):
@@ -104,6 +104,21 @@ class Delegate(Provider[Provider]):
     def set_provides(self, provides: Optional[Provider]) -> Delegate: ...
 
 
+class Aggregate(Provider[T]):
+    def __init__(self, provider_dict: Optional[_Dict[Any, Provider[T]]] = None, **provider_kwargs: Provider[T]): ...
+    def __getattr__(self, provider_name: Any) -> Provider[T]: ...
+
+    @overload
+    def __call__(self, provider_name: Optional[Any] = None, *args: Injection, **kwargs: Injection) -> T: ...
+    @overload
+    def __call__(self, provider_name: Optional[Any] = None, *args: Injection, **kwargs: Injection) -> Awaitable[T]: ...
+    def async_(self, provider_name: Optional[Any] = None, *args: Injection, **kwargs: Injection) -> Awaitable[T]: ...
+
+    @property
+    def providers(self) -> _Dict[Any, Provider[T]]: ...
+    def set_providers(self, provider_dict: Optional[_Dict[Any, Provider[T]]] = None, **provider_kwargs: Provider[T]) -> Aggregate[T]: ...
+
+
 class Dependency(Provider[T]):
     def __init__(self, instance_of: Type[T] = object, default: Optional[Union[Provider, Any]] = None) -> None: ...
     def __getattr__(self, name: str) -> Any: ...
@@ -143,10 +158,10 @@ class DependenciesContainer(Object):
 
 
 class Callable(Provider[T]):
-    def __init__(self, provides: Optional[_Callable[..., T]] = None, *args: Injection, **kwargs: Injection) -> None: ...
+    def __init__(self, provides: Optional[Union[_Callable[..., T], str]] = None, *args: Injection, **kwargs: Injection) -> None: ...
     @property
     def provides(self) -> Optional[_Callable[..., T]]: ...
-    def set_provides(self, provides: Optional[_Callable[..., T]]) -> Callable[T]: ...
+    def set_provides(self, provides: Optional[Union[_Callable[..., T], str]]) -> Callable[T]: ...
     @property
     def args(self) -> Tuple[Injection]: ...
     def add_args(self, *args: Injection) -> Callable[T]: ...
@@ -205,7 +220,7 @@ class ConfigurationOption(Provider[Any]):
     def from_yaml(self, filepath: Union[Path, str], required: bool = False, loader: Optional[Any] = None, envs_required: bool = False) -> None: ...
     def from_pydantic(self, settings: PydanticSettings, required: bool = False, **kwargs: Any) -> None: ...
     def from_dict(self, options: _Dict[str, Any], required: bool = False) -> None: ...
-    def from_env(self, name: str, default: Optional[Any] = None, required: bool = False) -> None: ...
+    def from_env(self, name: str, default: Optional[Any] = None, required: bool = False, as_: Optional[_Callable[..., Any]] = None) -> None: ...
     def from_value(self, value: Any) -> None: ...
 
 
@@ -215,7 +230,7 @@ class TypedConfigurationOption(Callable[T]):
 
 
 class Configuration(Object[Any]):
-    DEFAULT_NAME: str = 'config'
+    DEFAULT_NAME: str = "config"
     def __init__(
             self,
             name: str = DEFAULT_NAME,
@@ -262,18 +277,18 @@ class Configuration(Object[Any]):
     def from_yaml(self, filepath: Union[Path, str], required: bool = False, loader: Optional[Any] = None, envs_required: bool = False) -> None: ...
     def from_pydantic(self, settings: PydanticSettings, required: bool = False, **kwargs: Any) -> None: ...
     def from_dict(self, options: _Dict[str, Any], required: bool = False) -> None: ...
-    def from_env(self, name: str, default: Optional[Any] = None, required: bool = False) -> None: ...
+    def from_env(self, name: str, default: Optional[Any] = None, required: bool = False, as_: Optional[_Callable[..., Any]] = None) -> None: ...
     def from_value(self, value: Any) -> None: ...
 
 
 class Factory(Provider[T]):
     provided_type: Optional[Type]
-    def __init__(self, provides: Optional[_Callable[..., T]] = None, *args: Injection, **kwargs: Injection) -> None: ...
+    def __init__(self, provides: Optional[Union[_Callable[..., T], str]] = None, *args: Injection, **kwargs: Injection) -> None: ...
     @property
     def cls(self) -> Type[T]: ...
     @property
     def provides(self) -> Optional[_Callable[..., T]]: ...
-    def set_provides(self, provides: Optional[_Callable[..., T]]) -> Factory[T]: ...
+    def set_provides(self, provides: Optional[Union[_Callable[..., T], str]]) -> Factory[T]: ...
     @property
     def args(self) -> Tuple[Injection]: ...
     def add_args(self, *args: Injection) -> Factory[T]: ...
@@ -302,29 +317,21 @@ class FactoryDelegate(Delegate):
     def __init__(self, factory: Factory): ...
 
 
-class FactoryAggregate(Provider[T]):
-    def __init__(self, dict_: Optional[_Dict[Any, Factory[T]]] = None, **factories: Factory[T]): ...
-    def __getattr__(self, factory_name: Any) -> Factory[T]: ...
-
-    @overload
-    def __call__(self, factory_name: Any, *args: Injection, **kwargs: Injection) -> T: ...
-    @overload
-    def __call__(self, factory_name: Any, *args: Injection, **kwargs: Injection) -> Awaitable[T]: ...
-    def async_(self, factory_name: Any, *args: Injection, **kwargs: Injection) -> Awaitable[T]: ...
-
+class FactoryAggregate(Aggregate[T]):
+    def __getattr__(self, provider_name: Any) -> Factory[T]: ...
     @property
     def factories(self) -> _Dict[Any, Factory[T]]: ...
-    def set_factories(self, dict_: Optional[_Dict[Any, Factory[T]]] = None, **factories: Factory[T]) -> FactoryAggregate[T]: ...
+    def set_factories(self, provider_dict: Optional[_Dict[Any, Factory[T]]] = None, **provider_kwargs: Factory[T]) -> FactoryAggregate[T]: ...
 
 
 class BaseSingleton(Provider[T]):
     provided_type = Optional[Type]
-    def __init__(self, provides: Optional[_Callable[..., T]] = None, *args: Injection, **kwargs: Injection) -> None: ...
+    def __init__(self, provides: Optional[Union[_Callable[..., T], str]] = None, *args: Injection, **kwargs: Injection) -> None: ...
     @property
     def cls(self) -> Type[T]: ...
     @property
     def provides(self) -> Optional[_Callable[..., T]]: ...
-    def set_provides(self, provides: Optional[_Callable[..., T]]) -> BaseSingleton[T]: ...
+    def set_provides(self, provides: Optional[Union[_Callable[..., T], str]]) -> BaseSingleton[T]: ...
     @property
     def args(self) -> Tuple[Injection]: ...
     def add_args(self, *args: Injection) -> BaseSingleton[T]: ...
@@ -370,7 +377,7 @@ class AbstractSingleton(BaseSingleton[T]):
 
 
 class SingletonDelegate(Delegate):
-    def __init__(self, factory: BaseSingleton): ...
+    def __init__(self, singleton: BaseSingleton): ...
 
 
 class List(Provider[_List]):
@@ -403,7 +410,7 @@ class Resource(Provider[T]):
     @overload
     def __init__(self, provides: Optional[_Callable[..., _Coroutine[Injection, Injection, T]]] = None, *args: Injection, **kwargs: Injection) -> None: ...
     @overload
-    def __init__(self, provides: Optional[_Callable[..., T]] = None, *args: Injection, **kwargs: Injection) -> None: ...
+    def __init__(self, provides: Optional[Union[_Callable[..., T], str]] = None, *args: Injection, **kwargs: Injection) -> None: ...
     @property
     def provides(self) -> Optional[_Callable[..., Any]]: ...
     def set_provides(self, provides: Optional[Any]) -> Resource[T]: ...
@@ -483,7 +490,9 @@ class MethodCaller(Provider, ProvidedInstanceFluentInterface):
 class OverridingContext(Generic[T]):
     def __init__(self, overridden: Provider, overriding: Provider): ...
     def __enter__(self) -> T: ...
-    def __exit__(self, *_: Any) -> None: ...
+    def __exit__(self, *_: Any) -> None:
+        pass
+    ...
 
 
 class BaseSingletonResetContext(Generic[T]):

src/dependency_injector/resources.py

@@ -4,7 +4,7 @@ import abc
 from typing import TypeVar, Generic, Optional
 
 
-T = TypeVar('T')
+T = TypeVar("T")
 
 
 class Resource(Generic[T], metaclass=abc.ABCMeta):

src/dependency_injector/schema.py

@@ -19,8 +19,8 @@ class SchemaProcessorV1:
 
     def process(self):
         """Process schema."""
-        self._create_providers(self._schema['container'])
-        self._setup_injections(self._schema['container'])
+        self._create_providers(self._schema["container"])
+        self._setup_injections(self._schema["container"])
 
     def get_providers(self):
         """Return providers."""
@@ -36,11 +36,11 @@ class SchemaProcessorV1:
         for provider_name, data in provider_schema.items():
             provider = None
 
-            if 'provider' in data:
-                provider_type = _get_provider_cls(data['provider'])
+            if "provider" in data:
+                provider_type = _get_provider_cls(data["provider"])
                 args = []
 
-                # provides = data.get('provides')
+                # provides = data.get("provides")
                 # if provides:
                 #     provides = _import_string(provides)
                 #     if provides:
@@ -69,38 +69,38 @@ class SchemaProcessorV1:
             args = []
             kwargs = {}
 
-            provides = data.get('provides')
+            provides = data.get("provides")
             if provides:
-                if isinstance(provides, str) and provides.startswith('container.'):
-                    provides = self._resolve_provider(provides[len('container.'):])
+                if isinstance(provides, str) and provides.startswith("container."):
+                    provides = self._resolve_provider(provides[len("container."):])
                 else:
                     provides = _import_string(provides)
                 provider.set_provides(provides)
 
-            arg_injections = data.get('args')
+            arg_injections = data.get("args")
             if arg_injections:
                 for arg in arg_injections:
                     injection = None
 
-                    if isinstance(arg, str) and arg.startswith('container.'):
-                        injection = self._resolve_provider(arg[len('container.'):])
+                    if isinstance(arg, str) and arg.startswith("container."):
+                        injection = self._resolve_provider(arg[len("container."):])
 
                     # TODO: refactoring
                     if isinstance(arg, dict):
                         provider_args = []
-                        provider_type = _get_provider_cls(arg.get('provider'))
-                        provides = arg.get('provides')
+                        provider_type = _get_provider_cls(arg.get("provider"))
+                        provides = arg.get("provides")
                         if provides:
-                            if isinstance(provides, str) and provides.startswith('container.'):
-                                provides = self._resolve_provider(provides[len('container.'):])
+                            if isinstance(provides, str) and provides.startswith("container."):
+                                provides = self._resolve_provider(provides[len("container."):])
                             else:
                                 provides = _import_string(provides)
                             provider_args.append(provides)
-                        for provider_arg in arg.get('args', []):
+                        for provider_arg in arg.get("args", []):
                             if isinstance(provider_arg, str) \
-                                    and provider_arg.startswith('container.'):
+                                    and provider_arg.startswith("container."):
                                 provider_args.append(
-                                    self._resolve_provider(provider_arg[len('container.'):]),
+                                    self._resolve_provider(provider_arg[len("container."):]),
                                 )
                         injection = provider_type(*provider_args)
 
@@ -111,30 +111,30 @@ class SchemaProcessorV1:
             if args:
                 provider.add_args(*args)
 
-            kwarg_injections = data.get('kwargs')
+            kwarg_injections = data.get("kwargs")
             if kwarg_injections:
                 for name, arg in kwarg_injections.items():
                     injection = None
 
-                    if isinstance(arg, str) and arg.startswith('container.'):
-                        injection = self._resolve_provider(arg[len('container.'):])
+                    if isinstance(arg, str) and arg.startswith("container."):
+                        injection = self._resolve_provider(arg[len("container."):])
 
                     # TODO: refactoring
                     if isinstance(arg, dict):
                         provider_args = []
-                        provider_type = _get_provider_cls(arg.get('provider'))
-                        provides = arg.get('provides')
+                        provider_type = _get_provider_cls(arg.get("provider"))
+                        provides = arg.get("provides")
                         if provides:
-                            if isinstance(provides, str) and provides.startswith('container.'):
-                                provides = self._resolve_provider(provides[len('container.'):])
+                            if isinstance(provides, str) and provides.startswith("container."):
+                                provides = self._resolve_provider(provides[len("container."):])
                             else:
                                 provides = _import_string(provides)
                             provider_args.append(provides)
-                        for provider_arg in arg.get('args', []):
+                        for provider_arg in arg.get("args", []):
                             if isinstance(provider_arg, str) \
-                                    and provider_arg.startswith('container.'):
+                                    and provider_arg.startswith("container."):
                                 provider_args.append(
-                                    self._resolve_provider(provider_arg[len('container.'):]),
+                                    self._resolve_provider(provider_arg[len("container."):]),
                                 )
                         injection = provider_type(*provider_args)
 
@@ -149,17 +149,17 @@ class SchemaProcessorV1:
                 self._setup_injections(provider_schema=data, container=provider)
 
     def _resolve_provider(self, name: str) -> Optional[providers.Provider]:
-        segments = name.split('.')
+        segments = name.split(".")
         try:
             provider = getattr(self._container, segments[0])
         except AttributeError:
             return None
 
         for segment in segments[1:]:
-            parentheses = ''
-            if '(' in segment and ')' in segment:
-                parentheses = segment[segment.find('('):segment.rfind(')')+1]
-                segment = segment.replace(parentheses, '')
+            parentheses = ""
+            if "(" in segment and ")" in segment:
+                parentheses = segment[segment.find("("):segment.rfind(")")+1]
+                segment = segment.replace(parentheses, "")
 
             try:
                 provider = getattr(provider, segment)
@@ -190,7 +190,7 @@ def _get_provider_cls(provider_cls_name: str) -> Type[providers.Provider]:
     if custom_provider_type:
         return custom_provider_type
 
-    raise SchemaError(f'Undefined provider class "{provider_cls_name}"')
+    raise SchemaError(f"Undefined provider class \"{provider_cls_name}\"")
 
 
 def _fetch_provider_cls_from_std(provider_cls_name: str) -> Optional[Type[providers.Provider]]:
@@ -201,24 +201,24 @@ def _import_provider_cls(provider_cls_name: str) -> Optional[Type[providers.Prov
     try:
         cls = _import_string(provider_cls_name)
     except (ImportError, ValueError) as exception:
-        raise SchemaError(f'Can not import provider "{provider_cls_name}"') from exception
+        raise SchemaError(f"Can not import provider \"{provider_cls_name}\"") from exception
     except AttributeError:
         return None
     else:
         if isinstance(cls, type) and not issubclass(cls, providers.Provider):
-            raise SchemaError(f'Provider class "{cls}" is not a subclass of providers base class')
+            raise SchemaError(f"Provider class \"{cls}\" is not a subclass of providers base class")
         return cls
 
 
 def _import_string(string_name: str) -> Optional[object]:
-    segments = string_name.split('.')
+    segments = string_name.split(".")
 
     if len(segments) == 1:
         member = getattr(builtins, segments[0], None)
         if member:
             return member
 
-    module_name = '.'.join(segments[:-1])
+    module_name = ".".join(segments[:-1])
     if not module_name:
         return None
 

src/dependency_injector/wiring.py

@@ -68,27 +68,27 @@ if sys.version_info[:2] == (3, 5):
     )
 
 __all__ = (
-    'wire',
-    'unwire',
-    'inject',
-    'as_int',
-    'as_float',
-    'as_',
-    'required',
-    'invariant',
-    'provided',
-    'Provide',
-    'Provider',
-    'Closing',
-    'register_loader_containers',
-    'unregister_loader_containers',
-    'install_loader',
-    'uninstall_loader',
-    'is_loader_installed',
+    "wire",
+    "unwire",
+    "inject",
+    "as_int",
+    "as_float",
+    "as_",
+    "required",
+    "invariant",
+    "provided",
+    "Provide",
+    "Provider",
+    "Closing",
+    "register_loader_containers",
+    "unregister_loader_containers",
+    "install_loader",
+    "uninstall_loader",
+    "is_loader_installed",
 )
 
-T = TypeVar('T')
-F = TypeVar('F', bound=Callable[..., Any])
+T = TypeVar("T")
+F = TypeVar("F", bound=Callable[..., Any])
 Container = Any
 
 
@@ -107,10 +107,10 @@ class PatchedRegistry:
                 continue
             yield patched
 
-    def add_attribute(self, patched: 'PatchedAttribute'):
+    def add_attribute(self, patched: "PatchedAttribute"):
         self._attributes.add(patched)
 
-    def get_attributes_from_module(self, module: ModuleType) -> Iterator['PatchedAttribute']:
+    def get_attributes_from_module(self, module: ModuleType) -> Iterator["PatchedAttribute"]:
         for attribute in self._attributes:
             if not attribute.is_in_module(module):
                 continue
@@ -125,7 +125,7 @@ class PatchedRegistry:
 
 class PatchedAttribute:
 
-    def __init__(self, member: Any, name: str, marker: '_Marker'):
+    def __init__(self, member: Any, name: str, marker: "_Marker"):
         self.member = member
         self.name = name
         self.marker = marker
@@ -143,7 +143,7 @@ class PatchedAttribute:
 
 class ProvidersMap:
 
-    CONTAINER_STRING_ID = '<container>'
+    CONTAINER_STRING_ID = "<container>"
 
     def __init__(self, container):
         self._container = container
@@ -159,7 +159,7 @@ class ProvidersMap:
     def resolve_provider(
             self,
             provider: Union[providers.Provider, str],
-            modifier: Optional['Modifier'] = None,
+            modifier: Optional["Modifier"] = None,
     ) -> Optional[providers.Provider]:
         if isinstance(provider, providers.Delegate):
             return self._resolve_delegate(provider)
@@ -182,13 +182,13 @@ class ProvidersMap:
     def _resolve_string_id(
             self,
             id: str,
-            modifier: Optional['Modifier'] = None,
+            modifier: Optional["Modifier"] = None,
     ) -> Optional[providers.Provider]:
         if id == self.CONTAINER_STRING_ID:
             return self._container.__self__
 
         provider = self._container
-        for segment in id.split('.'):
+        for segment in id.split("."):
             try:
                 provider = getattr(provider, segment)
             except AttributeError:
@@ -282,10 +282,10 @@ class ProvidersMap:
             original_container: Container,
     ) -> Dict[providers.Provider, providers.Provider]:
         current_providers = current_container.providers
-        current_providers['__self__'] = current_container.__self__
+        current_providers["__self__"] = current_container.__self__
 
         original_providers = original_container.providers
-        original_providers['__self__'] = original_container.__self__
+        original_providers["__self__"] = original_container.__self__
 
         providers_map = {}
         for provider_name, current_provider in current_providers.items():
@@ -429,7 +429,7 @@ def _patch_method(
         method: Callable[..., Any],
         providers_map: ProvidersMap,
 ) -> None:
-    if hasattr(cls, '__dict__') \
+    if hasattr(cls, "__dict__") \
             and name in cls.__dict__ \
             and isinstance(cls.__dict__[name], (classmethod, staticmethod)):
         method = cls.__dict__[name]
@@ -457,7 +457,7 @@ def _unpatch(
         name: str,
         fn: Callable[..., Any],
 ) -> None:
-    if hasattr(module, '__dict__') \
+    if hasattr(module, "__dict__") \
             and name in module.__dict__ \
             and isinstance(module.__dict__[name], (classmethod, staticmethod)):
         method = module.__dict__[name]
@@ -472,7 +472,7 @@ def _unpatch(
 def _patch_attribute(
         member: Any,
         name: str,
-        marker: '_Marker',
+        marker: "_Marker",
         providers_map: ProvidersMap,
 ) -> None:
     provider = providers_map.resolve_provider(marker.provider, marker.modifier)
@@ -487,7 +487,7 @@ def _patch_attribute(
     elif isinstance(marker, Provider):
         setattr(member, name, provider)
     else:
-        raise Exception(f'Unknown type of marker {marker}')
+        raise Exception(f"Unknown type of marker {marker}")
 
 
 def _unpatch_attribute(patched: PatchedAttribute) -> None:
@@ -502,16 +502,16 @@ def _fetch_reference_injections(  # noqa: C901
     # - https://github.com/ets-labs/python-dependency-injector/issues/398
     if GenericAlias and any((
                 fn is GenericAlias,
-                getattr(fn, '__func__', None) is GenericAlias
+                getattr(fn, "__func__", None) is GenericAlias
             )):
         fn = fn.__init__
 
     try:
         signature = inspect.signature(fn)
     except ValueError as exception:
-        if 'no signature found' in str(exception):
+        if "no signature found" in str(exception):
             return {}, {}
-        elif 'not supported by signature' in str(exception):
+        elif "not supported by signature" in str(exception):
             return {}, {}
         else:
             raise exception
@@ -565,11 +565,11 @@ def _unbind_injections(fn: Callable[..., Any]) -> None:
 
 def _fetch_modules(package):
     modules = [package]
-    if not hasattr(package, '__path__') or not hasattr(package, '__name__'):
+    if not hasattr(package, "__path__") or not hasattr(package, "__name__"):
         return modules
     for module_info in pkgutil.walk_packages(
             path=package.__path__,
-            prefix=package.__name__ + '.',
+            prefix=package.__name__ + ".",
     ):
         module = importlib.import_module(module_info.name)
         modules.append(module)
@@ -670,13 +670,13 @@ def _is_fastapi_depends(param: Any) -> bool:
 
 
 def _is_patched(fn):
-    return getattr(fn, '__wired__', False) is True
+    return getattr(fn, "__wired__", False) is True
 
 
 def _is_declarative_container(instance: Any) -> bool:
     return (isinstance(instance, type)
-            and getattr(instance, '__IS_CONTAINER__', False) is True
-            and getattr(instance, 'declarative_parent', None) is None)
+            and getattr(instance, "__IS_CONTAINER__", False) is True
+            and getattr(instance, "declarative_parent", None) is None)
 
 
 class Modifier:
@@ -722,15 +722,15 @@ class RequiredModifier(Modifier):
     def __init__(self):
         self.type_modifier = None
 
-    def as_int(self) -> 'RequiredModifier':
+    def as_int(self) -> "RequiredModifier":
         self.type_modifier = TypeModifier(int)
         return self
 
-    def as_float(self) -> 'RequiredModifier':
+    def as_float(self) -> "RequiredModifier":
         self.type_modifier = TypeModifier(float)
         return self
 
-    def as_(self, type_: Type) -> 'RequiredModifier':
+    def as_(self, type_: Type) -> "RequiredModifier":
         self.type_modifier = TypeModifier(type_)
         return self
 
@@ -771,9 +771,9 @@ def invariant(id: str) -> InvariantModifier:
 
 class ProvidedInstance(Modifier):
 
-    TYPE_ATTRIBUTE = 'attr'
-    TYPE_ITEM = 'item'
-    TYPE_CALL = 'call'
+    TYPE_ATTRIBUTE = "attr"
+    TYPE_ITEM = "item"
+    TYPE_CALL = "call"
 
     def __init__(self):
         self.segments = []

tests/typing/aggregate.py

@@ -0,0 +1,32 @@
+from dependency_injector import providers
+
+
+class Animal:
+    ...
+
+
+class Cat(Animal):
+    ...
+
+
+# Test 1: to check Aggregate provider
+provider1: providers.Aggregate[str] = providers.Aggregate(
+    a=providers.Object("str1"),
+    b=providers.Object("str2"),
+)
+provider_a_1: providers.Provider[str] = provider1.a
+provider_b_1: providers.Provider[str] = provider1.b
+val1: str = provider1("a")
+
+provider1_set_non_string_keys: providers.Aggregate[str] = providers.Aggregate()
+provider1_set_non_string_keys.set_providers({Cat: providers.Object("str")})
+provider_set_non_string_1: providers.Provider[str] = provider1_set_non_string_keys.providers[Cat]
+
+provider1_new_non_string_keys: providers.Aggregate[str] = providers.Aggregate(
+    {Cat: providers.Object("str")},
+)
+factory_new_non_string_1: providers.Provider[str] = provider1_new_non_string_keys.providers[Cat]
+
+provider1_no_explicit_typing = providers.Aggregate(a=providers.Object("str"))
+provider1_no_explicit_typing_factory: providers.Provider[str] = provider1_no_explicit_typing.providers["a"]
+provider1_no_explicit_typing_object: str = provider1_no_explicit_typing("a")

tests/typing/callable.py

@@ -66,3 +66,7 @@ assert provides10 is Cat
 provider11 = providers.Callable[Animal](Cat)
 provides11: Optional[Callable[..., Animal]] = provider11.provides
 assert provides11 is Cat
+
+# Test 12: to check string imports
+provider12: providers.Callable[dict] = providers.Callable("builtins.dict")
+provider12.set_provides("builtins.dict")

tests/typing/configuration.py

@@ -14,7 +14,11 @@ config2.from_ini(Path("config.ini"))
 
 config2.from_yaml("config.yml")
 config2.from_yaml(Path("config.yml"))
+
 config2.from_env("ENV", "default")
+config2.from_env("ENV", as_=int, default=123)
+config2.from_env("ENV", as_=float, required=True)
+config2.from_env("ENV", as_=lambda env: str(env))
 
 # Test 3: to check as_*() methods
 config3 = providers.Configuration()

tests/typing/coroutine.py

@@ -9,3 +9,7 @@ async def _coro() -> None:
 # Test 1: to check the return type
 provider1 = providers.Coroutine(_coro)
 var1: Coroutine = provider1()
+
+# Test 2: to check string imports
+provider2: providers.Coroutine[None] = providers.Coroutine("_coro")
+provider2.set_provides("_coro")

tests/typing/factory.py

@@ -99,3 +99,7 @@ provided_cls13: Type[Animal] = provider13.cls
 assert issubclass(provided_cls13, Animal)
 provided_provides13: Optional[Callable[..., Animal]] = provider13.provides
 assert provided_provides13 is not None and provided_provides13() == Cat()
+
+# Test 14: to check string imports
+provider14: providers.Factory[dict] = providers.Factory("builtins.dict")
+provider14.set_provides("builtins.dict")

tests/typing/resource.py

@@ -97,3 +97,8 @@ provider8 = providers.Resource(MyResource8)
 async def _provide8() -> None:
     var1: List[int] = await provider8()  # type: ignore
     var2: List[int] = await provider8.async_()
+
+
+# Test 9: to check string imports
+provider9: providers.Resource[dict] = providers.Resource("builtins.dict")
+provider9.set_provides("builtins.dict")

tests/typing/singleton.py

@@ -89,3 +89,7 @@ provided_cls15: Type[Animal] = provider15.cls
 assert issubclass(provided_cls15, Animal)
 provided_provides15: Optional[Callable[..., Animal]] = provider15.provides
 assert provided_provides15 is not None and provided_provides15() == Cat()
+
+# Test 16: to check string imports
+provider16: providers.Singleton[dict] = providers.Singleton("builtins.dict")
+provider16.set_provides("builtins.dict")

tests/unit/providers/callables/test_callable_py2_py3.py

@@ -1,9 +1,10 @@
 """Callable provider tests."""
 
+import decimal
 import sys
 
 from dependency_injector import providers, errors
-from pytest import raises
+from pytest import raises, mark
 
 from .common import example
 
@@ -29,6 +30,20 @@ def test_set_provides_returns_():
     assert provider.set_provides(object) is provider
 
 
+@mark.parametrize(
+    "str_name,cls",
+    [
+        ("dependency_injector.providers.Factory", providers.Factory),
+        ("decimal.Decimal", decimal.Decimal),
+        ("list", list),
+        (".common.example", example),
+        ("test_is_provider", test_is_provider),
+    ],
+)
+def test_set_provides_string_imports(str_name, cls):
+    assert providers.Callable(str_name).provides is cls
+
+
 def test_provided_instance_provider():
     provider = providers.Callable(example)
     assert isinstance(provider.provided, providers.ProvidedInstance)

tests/unit/providers/configuration/conftest.py

@@ -106,7 +106,11 @@ def environment_variables():
     os.environ["CONFIG_TEST_ENV"] = "test-value"
     os.environ["CONFIG_TEST_PATH"] = "test-path"
     os.environ["DEFINED"] = "defined"
+    os.environ["EMPTY"] = ""
+    os.environ["CONFIG_INT"] = "42"
     yield
     os.environ.pop("CONFIG_TEST_ENV", None)
     os.environ.pop("CONFIG_TEST_PATH", None)
     os.environ.pop("DEFINED", None)
+    os.environ.pop("EMPTY", None)
+    os.environ.pop("CONFIG_INT", None)

tests/unit/providers/configuration/test_from_env_py2_py3.py

@@ -31,6 +31,54 @@ def test_option_default_none(config):
     assert config.option() is None
 
 
+def test_as_(config):
+    config.from_env("CONFIG_INT", as_=int)
+    assert config() == 42
+    assert isinstance(config(), int)
+
+
+def test_as__default(config):
+    config.from_env("UNDEFINED", as_=int, default="33")
+    assert config() == 33
+    assert isinstance(config(), int)
+
+
+def test_as__undefined_required(config):
+    with raises(ValueError):
+        config.from_env("UNDEFINED", as_=int, required=True)
+    assert config() == {}
+
+
+def test_as__defined_empty(config):
+    with raises(ValueError):
+        config.from_env("EMPTY", as_=int)
+    assert config() == {}
+
+
+def test_option_as_(config):
+    config.option.from_env("CONFIG_INT", as_=int)
+    assert config.option() == 42
+    assert isinstance(config.option(), int)
+
+
+def test_option_as__default(config):
+    config.option.from_env("UNDEFINED", as_=int, default="33")
+    assert config.option() == 33
+    assert isinstance(config.option(), int)
+
+
+def test_option_as__undefined_required(config):
+    with raises(ValueError):
+        config.option.from_env("UNDEFINED", as_=int, required=True)
+    assert config.option() is None
+
+
+def test_option_as__defined_empty(config):
+    with raises(ValueError):
+        config.option.from_env("EMPTY", as_=int)
+    assert config.option() is None
+
+
 @mark.parametrize("config_type", ["strict"])
 def test_undefined_in_strict_mode(config):
     with raises(ValueError):

tests/unit/providers/coroutines/test_coroutine_py35.py

@@ -31,6 +31,17 @@ def test_set_provides_returns_self():
     assert provider.set_provides(example) is provider
 
 
+@mark.parametrize(
+    "str_name,cls",
+    [
+        (".common.example", example),
+        ("example", example),
+    ],
+)
+def test_set_provides_string_imports(str_name, cls):
+    assert providers.Coroutine(str_name).provides is cls
+
+
 @mark.asyncio
 async def test_call_with_positional_args():
     provider = providers.Coroutine(example, 1, 2, 3, 4)

tests/unit/providers/factories/test_factory_aggregate_py2_py3.py

@@ -78,6 +78,52 @@ def test_init_with_not_a_factory():
         )
 
 
+@mark.parametrize("factory_type", ["empty"])
+def test_init_optional_providers(factory_aggregate, factory_a, factory_b):
+    factory_aggregate.set_providers(
+        example_a=factory_a,
+        example_b=factory_b,
+    )
+    assert factory_aggregate.providers == {
+        "example_a": factory_a,
+        "example_b": factory_b,
+    }
+    assert isinstance(factory_aggregate("example_a"), ExampleA)
+    assert isinstance(factory_aggregate("example_b"), ExampleB)
+
+
+@mark.parametrize("factory_type", ["non-string-keys"])
+def test_set_factories_with_non_string_keys(factory_aggregate, factory_a, factory_b):
+    factory_aggregate.set_providers({
+        ExampleA: factory_a,
+        ExampleB: factory_b,
+    })
+
+    object_a = factory_aggregate(ExampleA, 1, 2, init_arg3=3, init_arg4=4)
+    object_b = factory_aggregate(ExampleB, 11, 22, init_arg3=33, init_arg4=44)
+
+    assert isinstance(object_a, ExampleA)
+    assert object_a.init_arg1 == 1
+    assert object_a.init_arg2 == 2
+    assert object_a.init_arg3 == 3
+    assert object_a.init_arg4 == 4
+
+    assert isinstance(object_b, ExampleB)
+    assert object_b.init_arg1 == 11
+    assert object_b.init_arg2 == 22
+    assert object_b.init_arg3 == 33
+    assert object_b.init_arg4 == 44
+
+    assert factory_aggregate.providers == {
+        ExampleA: factory_a,
+        ExampleB: factory_b,
+    }
+
+
+def test_set_providers_returns_self(factory_aggregate, factory_a):
+    assert factory_aggregate.set_providers(example_a=factory_a) is factory_aggregate
+
+
 @mark.parametrize("factory_type", ["empty"])
 def test_init_optional_factories(factory_aggregate, factory_a, factory_b):
     factory_aggregate.set_factories(

tests/unit/providers/factories/test_factory_py2_py3.py

@@ -1,9 +1,10 @@
 """Factory provider tests."""
 
+import decimal
 import sys
 
 from dependency_injector import providers, errors
-from pytest import raises
+from pytest import raises, mark
 
 from .common import Example
 
@@ -29,6 +30,20 @@ def test_set_provides_returns_():
     assert provider.set_provides(object) is provider
 
 
+@mark.parametrize(
+    "str_name,cls",
+    [
+        ("dependency_injector.providers.Factory", providers.Factory),
+        ("decimal.Decimal", decimal.Decimal),
+        ("list", list),
+        (".common.Example", Example),
+        ("test_is_provider", test_is_provider),
+    ],
+)
+def test_set_provides_string_imports(str_name, cls):
+    assert providers.Factory(str_name).provides is cls
+
+
 def test_init_with_valid_provided_type():
     class ExampleProvider(providers.Factory):
         provided_type = Example

tests/unit/providers/resource/test_resource_py35.py

@@ -1,10 +1,11 @@
 """Resource provider tests."""
 
+import decimal
 import sys
 from typing import Any
 
 from dependency_injector import containers, providers, resources, errors
-from pytest import raises
+from pytest import raises, mark
 
 
 def init_fn(*args, **kwargs):
@@ -27,6 +28,20 @@ def test_set_provides_returns_():
     assert provider.set_provides(init_fn) is provider
 
 
+@mark.parametrize(
+    "str_name,cls",
+    [
+        ("dependency_injector.providers.Factory", providers.Factory),
+        ("decimal.Decimal", decimal.Decimal),
+        ("list", list),
+        (".test_resource_py35.test_is_provider", test_is_provider),
+        ("test_is_provider", test_is_provider),
+    ],
+)
+def test_set_provides_string_imports(str_name, cls):
+    assert providers.Resource(str_name).provides is cls
+
+
 def test_provided_instance_provider():
     provider = providers.Resource(init_fn)
     assert isinstance(provider.provided, providers.ProvidedInstance)

tests/unit/providers/singleton/test_singleton_py2_py3.py

@@ -1,9 +1,9 @@
 """Singleton provider tests."""
-
+import decimal
 import sys
 
 from dependency_injector import providers, errors
-from pytest import fixture, raises
+from pytest import fixture, raises, mark
 
 from .common import Example
 
@@ -49,6 +49,20 @@ def test_set_provides_returns_self(provider):
     assert provider.set_provides(object) is provider
 
 
+@mark.parametrize(
+    "str_name,cls",
+    [
+        ("dependency_injector.providers.Factory", providers.Factory),
+        ("decimal.Decimal", decimal.Decimal),
+        ("list", list),
+        (".common.Example", Example),
+        ("test_is_provider", test_is_provider),
+    ],
+)
+def test_set_provides_string_imports(str_name, cls):
+    assert providers.Singleton(str_name).provides is cls
+
+
 def test_init_with_valid_provided_type(singleton_cls):
     class ExampleProvider(singleton_cls):
         provided_type = Example

tests/unit/providers/test_aggregate_py2_py3.py

@@ -0,0 +1,292 @@
+"""Aggregate provider tests."""
+
+from dependency_injector import providers, errors
+from pytest import fixture, mark, raises
+
+
+class Example:
+    def __init__(self, init_arg1=None, init_arg2=None, init_arg3=None, init_arg4=None):
+        self.init_arg1 = init_arg1
+        self.init_arg2 = init_arg2
+        self.init_arg3 = init_arg3
+        self.init_arg4 = init_arg4
+
+        self.attribute1 = None
+        self.attribute2 = None
+
+
+class ExampleA(Example):
+    pass
+
+
+class ExampleB(Example):
+    pass
+
+
+@fixture
+def factory_a():
+    return providers.Factory(ExampleA)
+
+
+@fixture
+def factory_b():
+    return providers.Factory(ExampleB)
+
+
+@fixture
+def aggregate_type():
+    return "default"
+
+
+@fixture
+def aggregate(aggregate_type, factory_a, factory_b):
+    if aggregate_type == "empty":
+        return providers.Aggregate()
+    elif aggregate_type == "non-string-keys":
+        return providers.Aggregate({
+            ExampleA: factory_a,
+            ExampleB: factory_b,
+        })
+    elif aggregate_type == "default":
+        return providers.Aggregate(
+            example_a=factory_a,
+            example_b=factory_b,
+        )
+    else:
+        raise ValueError("Unknown factory type \"{0}\"".format(aggregate_type))
+
+
+def test_is_provider(aggregate):
+    assert providers.is_provider(aggregate) is True
+
+
+def test_is_delegated_provider(aggregate):
+    assert providers.is_delegated(aggregate) is True
+
+
+@mark.parametrize("aggregate_type", ["non-string-keys"])
+def test_init_with_non_string_keys(aggregate, factory_a, factory_b):
+    object_a = aggregate(ExampleA, 1, 2, init_arg3=3, init_arg4=4)
+    object_b = aggregate(ExampleB, 11, 22, init_arg3=33, init_arg4=44)
+
+    assert isinstance(object_a, ExampleA)
+    assert object_a.init_arg1 == 1
+    assert object_a.init_arg2 == 2
+    assert object_a.init_arg3 == 3
+    assert object_a.init_arg4 == 4
+
+    assert isinstance(object_b, ExampleB)
+    assert object_b.init_arg1 == 11
+    assert object_b.init_arg2 == 22
+    assert object_b.init_arg3 == 33
+    assert object_b.init_arg4 == 44
+
+    assert aggregate.providers == {
+        ExampleA: factory_a,
+        ExampleB: factory_b,
+    }
+
+
+def test_init_with_not_a_factory():
+    with raises(errors.Error):
+        providers.Aggregate(
+            example_a=providers.Factory(ExampleA),
+            example_b=object(),
+        )
+
+
+@mark.parametrize("aggregate_type", ["empty"])
+def test_init_optional_providers(aggregate, factory_a, factory_b):
+    aggregate.set_providers(
+        example_a=factory_a,
+        example_b=factory_b,
+    )
+    assert aggregate.providers == {
+        "example_a": factory_a,
+        "example_b": factory_b,
+    }
+    assert isinstance(aggregate("example_a"), ExampleA)
+    assert isinstance(aggregate("example_b"), ExampleB)
+
+
+@mark.parametrize("aggregate_type", ["non-string-keys"])
+def test_set_providers_with_non_string_keys(aggregate, factory_a, factory_b):
+    aggregate.set_providers({
+        ExampleA: factory_a,
+        ExampleB: factory_b,
+    })
+
+    object_a = aggregate(ExampleA, 1, 2, init_arg3=3, init_arg4=4)
+    object_b = aggregate(ExampleB, 11, 22, init_arg3=33, init_arg4=44)
+
+    assert isinstance(object_a, ExampleA)
+    assert object_a.init_arg1 == 1
+    assert object_a.init_arg2 == 2
+    assert object_a.init_arg3 == 3
+    assert object_a.init_arg4 == 4
+
+    assert isinstance(object_b, ExampleB)
+    assert object_b.init_arg1 == 11
+    assert object_b.init_arg2 == 22
+    assert object_b.init_arg3 == 33
+    assert object_b.init_arg4 == 44
+
+    assert aggregate.providers == {
+        ExampleA: factory_a,
+        ExampleB: factory_b,
+    }
+
+
+def test_set_providers_returns_self(aggregate, factory_a):
+    assert aggregate.set_providers(example_a=factory_a) is aggregate
+
+
+@mark.parametrize("aggregate_type", ["empty"])
+def test_init_optional_providers(aggregate, factory_a, factory_b):
+    aggregate.set_providers(
+        example_a=factory_a,
+        example_b=factory_b,
+    )
+    assert aggregate.providers == {
+        "example_a": factory_a,
+        "example_b": factory_b,
+    }
+    assert isinstance(aggregate("example_a"), ExampleA)
+    assert isinstance(aggregate("example_b"), ExampleB)
+
+
+@mark.parametrize("aggregate_type", ["non-string-keys"])
+def test_set_providers_with_non_string_keys(aggregate, factory_a, factory_b):
+    aggregate.set_providers({
+        ExampleA: factory_a,
+        ExampleB: factory_b,
+    })
+
+    object_a = aggregate(ExampleA, 1, 2, init_arg3=3, init_arg4=4)
+    object_b = aggregate(ExampleB, 11, 22, init_arg3=33, init_arg4=44)
+
+    assert isinstance(object_a, ExampleA)
+    assert object_a.init_arg1 == 1
+    assert object_a.init_arg2 == 2
+    assert object_a.init_arg3 == 3
+    assert object_a.init_arg4 == 4
+
+    assert isinstance(object_b, ExampleB)
+    assert object_b.init_arg1 == 11
+    assert object_b.init_arg2 == 22
+    assert object_b.init_arg3 == 33
+    assert object_b.init_arg4 == 44
+
+    assert aggregate.providers == {
+        ExampleA: factory_a,
+        ExampleB: factory_b,
+    }
+
+
+def test_set_providers_returns_self(aggregate, factory_a):
+    assert aggregate.set_providers(example_a=factory_a) is aggregate
+
+
+def test_call(aggregate):
+    object_a = aggregate("example_a", 1, 2, init_arg3=3, init_arg4=4)
+    object_b = aggregate("example_b", 11, 22, init_arg3=33, init_arg4=44)
+
+    assert isinstance(object_a, ExampleA)
+    assert object_a.init_arg1 == 1
+    assert object_a.init_arg2 == 2
+    assert object_a.init_arg3 == 3
+    assert object_a.init_arg4 == 4
+
+    assert isinstance(object_b, ExampleB)
+    assert object_b.init_arg1 == 11
+    assert object_b.init_arg2 == 22
+    assert object_b.init_arg3 == 33
+    assert object_b.init_arg4 == 44
+
+
+def test_call_factory_name_as_kwarg(aggregate):
+    object_a = aggregate(
+        factory_name="example_a",
+        init_arg1=1,
+        init_arg2=2,
+        init_arg3=3,
+        init_arg4=4,
+    )
+    assert isinstance(object_a, ExampleA)
+    assert object_a.init_arg1 == 1
+    assert object_a.init_arg2 == 2
+    assert object_a.init_arg3 == 3
+    assert object_a.init_arg4 == 4
+
+
+def test_call_no_factory_name(aggregate):
+    with raises(TypeError):
+        aggregate()
+
+
+def test_call_no_such_provider(aggregate):
+    with raises(errors.NoSuchProviderError):
+        aggregate("unknown")
+
+
+def test_overridden(aggregate):
+    with raises(errors.Error):
+        aggregate.override(providers.Object(object()))
+
+
+def test_getattr(aggregate, factory_a, factory_b):
+    assert aggregate.example_a is factory_a
+    assert aggregate.example_b is factory_b
+
+
+def test_getattr_no_such_provider(aggregate):
+    with raises(errors.NoSuchProviderError):
+        aggregate.unknown
+
+
+def test_providers(aggregate, factory_a, factory_b):
+    assert aggregate.providers == dict(
+        example_a=factory_a,
+        example_b=factory_b,
+    )
+
+
+def test_deepcopy(aggregate):
+    provider_copy = providers.deepcopy(aggregate)
+
+    assert aggregate is not provider_copy
+    assert isinstance(provider_copy, type(aggregate))
+
+    assert aggregate.example_a is not provider_copy.example_a
+    assert isinstance(aggregate.example_a, type(provider_copy.example_a))
+    assert aggregate.example_a.cls is provider_copy.example_a.cls
+
+    assert aggregate.example_b is not provider_copy.example_b
+    assert isinstance(aggregate.example_b, type(provider_copy.example_b))
+    assert aggregate.example_b.cls is provider_copy.example_b.cls
+
+
+@mark.parametrize("aggregate_type", ["non-string-keys"])
+def test_deepcopy_with_non_string_keys(aggregate):
+    provider_copy = providers.deepcopy(aggregate)
+
+    assert aggregate is not provider_copy
+    assert isinstance(provider_copy, type(aggregate))
+
+    assert aggregate.providers[ExampleA] is not provider_copy.providers[ExampleA]
+    assert isinstance(aggregate.providers[ExampleA], type(provider_copy.providers[ExampleA]))
+    assert aggregate.providers[ExampleA].provides is provider_copy.providers[ExampleA].provides
+
+    assert aggregate.providers[ExampleB] is not provider_copy.providers[ExampleB]
+    assert isinstance(aggregate.providers[ExampleB], type(provider_copy.providers[ExampleB]))
+    assert aggregate.providers[ExampleB].provides is provider_copy.providers[ExampleB].provides
+
+
+def test_repr(aggregate):
+    assert repr(aggregate) == (
+        "<dependency_injector.providers."
+        "Aggregate({0}) at {1}>".format(
+            repr(aggregate.providers),
+            hex(id(aggregate)),
+        )
+    )

tests/unit/providers/test_dependency_py2_py3.py

@@ -77,6 +77,22 @@ def test_default_attribute_provider():
     assert provider.default is default
 
 
+def test_default_with_empty_dict():
+    # See: https://github.com/ets-labs/python-dependency-injector/issues/550
+    default = {}
+    provider = providers.Dependency(instance_of=dict, default=default)
+    assert provider() == default
+    assert provider.default() == default
+
+
+def test_default_with_empty_string():
+    # See: https://github.com/ets-labs/python-dependency-injector/issues/550
+    default = ""
+    provider = providers.Dependency(instance_of=str, default=default)
+    assert provider() == default
+    assert provider.default() == default
+
+
 def test_is_defined(provider):
     assert provider.is_defined is False