diff --git a/examples/containers/check_dependencies.py b/examples/containers/check_dependencies.py
index f9d1bac2..24b3b88e 100644
--- a/examples/containers/check_dependencies.py
+++ b/examples/containers/check_dependencies.py
@@ -9,7 +9,7 @@ class Container(containers.DeclarativeContainer):
     service2 = providers.Dependency()
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     container = Container()
     container.check_dependencies()  # <-- raises error:
     # Container has undefined dependencies: "Container.service1", "Container.service2"
diff --git a/examples/containers/declarative.py b/examples/containers/declarative.py
index 4fb7d795..21a43174 100644
--- a/examples/containers/declarative.py
+++ b/examples/containers/declarative.py
@@ -10,7 +10,7 @@ class Container(containers.DeclarativeContainer):
     factory2 = providers.Factory(object)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     container = Container()
 
     object1 = container.factory1()
@@ -18,6 +18,6 @@ if __name__ == '__main__':
 
     print(container.providers)
     # {
-    #     'factory1': <dependency_injector.providers.Factory(...),
-    #     'factory2': <dependency_injector.providers.Factory(...),
+    #     "factory1": <dependency_injector.providers.Factory(...),
+    #     "factory2": <dependency_injector.providers.Factory(...),
     # }
diff --git a/examples/containers/declarative_copy_decorator1.py b/examples/containers/declarative_copy_decorator1.py
index 18fada24..d23bd4fd 100644
--- a/examples/containers/declarative_copy_decorator1.py
+++ b/examples/containers/declarative_copy_decorator1.py
@@ -13,7 +13,7 @@ class Service:
 
 class SourceContainer(containers.DeclarativeContainer):
 
-    database = providers.Singleton(sqlite3.connect, ':memory:')
+    database = providers.Singleton(sqlite3.connect, ":memory:")
     service = providers.Factory(Service, db=database)
 
 
@@ -24,7 +24,7 @@ class DestinationContainer(SourceContainer):
     database = providers.Singleton(mock.Mock)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     container = DestinationContainer()
 
     service = container.service()
diff --git a/examples/containers/declarative_copy_decorator2.py b/examples/containers/declarative_copy_decorator2.py
index 8fbc04f9..344c1bf0 100644
--- a/examples/containers/declarative_copy_decorator2.py
+++ b/examples/containers/declarative_copy_decorator2.py
@@ -9,21 +9,21 @@ class Service:
 
 
 class Base(containers.DeclarativeContainer):
-    dependency = providers.Dependency(instance_of=str, default='Default value')
+    dependency = providers.Dependency(instance_of=str, default="Default value")
     service = providers.Factory(Service, dependency=dependency)
 
 
 @containers.copy(Base)
 class Derived1(Base):
-    dependency = providers.Dependency(instance_of=str, default='Derived 1')
+    dependency = providers.Dependency(instance_of=str, default="Derived 1")
 
 
 # @containers.copy(Base)  # <-- No @copy decorator
 class Derived2(Base):
-    dependency = providers.Dependency(instance_of=str, default='Derived 2')
+    dependency = providers.Dependency(instance_of=str, default="Derived 2")
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     container1 = Derived1()
     service1 = container1.service()
     print(service1.dependency)  # Derived 1
diff --git a/examples/containers/declarative_inheritance.py b/examples/containers/declarative_inheritance.py
index 14621dad..d3e593b0 100644
--- a/examples/containers/declarative_inheritance.py
+++ b/examples/containers/declarative_inheritance.py
@@ -14,21 +14,21 @@ class ContainerB(ContainerA):
 
 
 assert ContainerA.providers == {
-    'provider1': ContainerA.provider1,
+    "provider1": ContainerA.provider1,
 }
 assert ContainerB.providers == {
-    'provider1': ContainerA.provider1,
-    'provider2': ContainerB.provider2,
+    "provider1": ContainerA.provider1,
+    "provider2": ContainerB.provider2,
 }
 
 assert ContainerA.cls_providers == {
-    'provider1': ContainerA.provider1,
+    "provider1": ContainerA.provider1,
 }
 assert ContainerB.cls_providers == {
-    'provider2': ContainerB.provider2,
+    "provider2": ContainerB.provider2,
 }
 
 assert ContainerA.inherited_providers == {}
 assert ContainerB.inherited_providers == {
-    'provider1': ContainerA.provider1,
+    "provider1": ContainerA.provider1,
 }
diff --git a/examples/containers/declarative_injections.py b/examples/containers/declarative_injections.py
index abfe9505..1db59f47 100644
--- a/examples/containers/declarative_injections.py
+++ b/examples/containers/declarative_injections.py
@@ -18,7 +18,7 @@ class AuthService:
 
 class Container(containers.DeclarativeContainer):
 
-    database = providers.Singleton(sqlite3.connect, ':memory:')
+    database = providers.Singleton(sqlite3.connect, ":memory:")
 
     user_service = providers.Factory(
         UserService,
@@ -32,7 +32,7 @@ class Container(containers.DeclarativeContainer):
     )
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     container = Container()
 
     user_service = container.user_service()
diff --git a/examples/containers/declarative_override_decorator.py b/examples/containers/declarative_override_decorator.py
index 16276d2f..17512e1c 100644
--- a/examples/containers/declarative_override_decorator.py
+++ b/examples/containers/declarative_override_decorator.py
@@ -8,7 +8,7 @@ from dependency_injector import containers, providers
 
 class Container(containers.DeclarativeContainer):
 
-    database = providers.Singleton(sqlite3.connect, ':memory:')
+    database = providers.Singleton(sqlite3.connect, ":memory:")
 
 
 # Overriding ``Container`` with ``OverridingContainer``:
@@ -18,7 +18,7 @@ class OverridingContainer(containers.DeclarativeContainer):
     database = providers.Singleton(mock.Mock)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     container = Container()
 
     database = container.database()
diff --git a/examples/containers/declarative_override_providers.py b/examples/containers/declarative_override_providers.py
index 0e92c1df..507eab98 100644
--- a/examples/containers/declarative_override_providers.py
+++ b/examples/containers/declarative_override_providers.py
@@ -8,10 +8,10 @@ from dependency_injector import containers, providers
 
 class Container(containers.DeclarativeContainer):
 
-    database = providers.Singleton(sqlite3.connect, ':memory:')
+    database = providers.Singleton(sqlite3.connect, ":memory:")
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     container = Container(database=mock.Mock(sqlite3.Connection))
 
     database = container.database()
diff --git a/examples/containers/dynamic.py b/examples/containers/dynamic.py
index 678351d6..5dc4a421 100644
--- a/examples/containers/dynamic.py
+++ b/examples/containers/dynamic.py
@@ -3,7 +3,7 @@
 from dependency_injector import containers, providers
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     container = containers.DynamicContainer()
     container.factory1 = providers.Factory(object)
     container.factory2 = providers.Factory(object)
@@ -13,6 +13,6 @@ if __name__ == '__main__':
 
     print(container.providers)
     # {
-    #     'factory1': <dependency_injector.providers.Factory(...),
-    #     'factory2': <dependency_injector.providers.Factory(...),
+    #     "factory1": <dependency_injector.providers.Factory(...),
+    #     "factory2": <dependency_injector.providers.Factory(...),
     # }
diff --git a/examples/containers/dynamic_runtime_creation.py b/examples/containers/dynamic_runtime_creation.py
index f95114fa..c525ad9c 100644
--- a/examples/containers/dynamic_runtime_creation.py
+++ b/examples/containers/dynamic_runtime_creation.py
@@ -13,20 +13,20 @@ class AuthService:
 
 def populate_container(container, providers_config):
     for provider_name, provider_info in providers_config.items():
-        provided_cls = globals().get(provider_info['class'])
-        provider_cls = getattr(providers, provider_info['provider_class'])
+        provided_cls = globals().get(provider_info["class"])
+        provider_cls = getattr(providers, provider_info["provider_class"])
         setattr(container, provider_name, provider_cls(provided_cls))
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     services_config = {
-        'user': {
-            'class': 'UserService',
-            'provider_class': 'Factory',
+        "user": {
+            "class": "UserService",
+            "provider_class": "Factory",
         },
-        'auth': {
-            'class': 'AuthService',
-            'provider_class': 'Factory',
+        "auth": {
+            "class": "AuthService",
+            "provider_class": "Factory",
         },
     }
     services = containers.DynamicContainer()
diff --git a/examples/containers/inject_self.py b/examples/containers/inject_self.py
index dbed8b15..6b8e1815 100644
--- a/examples/containers/inject_self.py
+++ b/examples/containers/inject_self.py
@@ -21,14 +21,14 @@ class Container(containers.DeclarativeContainer):
 
     __self__ = providers.Self()
 
-    service1 = providers.Factory(Service, name='Service 1')
-    service2 = providers.Factory(Service, name='Service 2')
-    service3 = providers.Factory(Service, name='Service 3')
+    service1 = providers.Factory(Service, name="Service 1")
+    service2 = providers.Factory(Service, name="Service 2")
+    service3 = providers.Factory(Service, name="Service 3")
 
     dispatcher = providers.Singleton(ServiceDispatcher, __self__)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     container = Container()
 
     dispatcher = container.dispatcher()
diff --git a/examples/containers/override.py b/examples/containers/override.py
index 268cc4d0..5ba606ff 100644
--- a/examples/containers/override.py
+++ b/examples/containers/override.py
@@ -21,7 +21,7 @@ class OverridingContainer(containers.DeclarativeContainer):
     service = providers.Factory(ServiceStub)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     container = Container()
     overriding_container = OverridingContainer()
 
diff --git a/examples/containers/reset_singletons.py b/examples/containers/reset_singletons.py
index 487ab13e..ed868552 100644
--- a/examples/containers/reset_singletons.py
+++ b/examples/containers/reset_singletons.py
@@ -9,7 +9,7 @@ class Container(containers.DeclarativeContainer):
     service2 = providers.Singleton(object)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     container = Container()
 
     service1 = container.service1()
diff --git a/examples/containers/reset_singletons_subcontainers.py b/examples/containers/reset_singletons_subcontainers.py
index 716ddb81..84f887fd 100644
--- a/examples/containers/reset_singletons_subcontainers.py
+++ b/examples/containers/reset_singletons_subcontainers.py
@@ -14,7 +14,7 @@ class Container(containers.DeclarativeContainer):
     sub = providers.Container(SubContainer)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     container = Container()
 
     service1 = container.service()
diff --git a/examples/containers/reset_singletons_with.py b/examples/containers/reset_singletons_with.py
index 6f919cb8..43ed8c40 100644
--- a/examples/containers/reset_singletons_with.py
+++ b/examples/containers/reset_singletons_with.py
@@ -8,7 +8,7 @@ class Container(containers.DeclarativeContainer):
     service = providers.Singleton(object)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     container = Container()
 
     service1 = container.service()
diff --git a/examples/containers/traverse.py b/examples/containers/traverse.py
index 3801aa0b..bda30522 100644
--- a/examples/containers/traverse.py
+++ b/examples/containers/traverse.py
@@ -34,15 +34,15 @@ class Container(containers.DeclarativeContainer):
     )
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     container = Container()
 
     for provider in container.traverse():
         print(provider)
 
-    # <dependency_injector.providers.Configuration('config') at 0x10d37d200>
-    # <dependency_injector.providers.Factory(<class '__main__.Service'>) at 0x10d3a2820>
+    # <dependency_injector.providers.Configuration("config") at 0x10d37d200>
+    # <dependency_injector.providers.Factory(<class "__main__.Service">) at 0x10d3a2820>
     # <dependency_injector.providers.Resource(<function init_database at 0x10bd2cb80>) at 0x10d346b40>
-    # <dependency_injector.providers.ConfigurationOption('config.cache_hosts') at 0x10d37d350>
+    # <dependency_injector.providers.ConfigurationOption("config.cache_hosts") at 0x10d37d350>
     # <dependency_injector.providers.Resource(<function init_cache at 0x10be373a0>) at 0x10d346bc0>
-    # <dependency_injector.providers.ConfigurationOption('config.database_url') at 0x10d37d2e0>
+    # <dependency_injector.providers.ConfigurationOption("config.database_url") at 0x10d37d2e0>