Providers

Providers help to assemble the objects. They create objects and inject the dependencies.

Each provider is a callable. You call the provider like a function when you need to create an object. Provider retrieves the underlying dependencies and inject them into the created object. It causes the cascade effect that helps to assemble object graphs. See Factory, Singleton, Callable and other provider docs below.

provider1()
│
├──> provider2()
│
├──> provider3()
│    │
│    └──> provider4()
│
└──> provider5()
     │
     └──> provider6()

Another providers feature is an overriding. You can override any provider with another provider. This helps in testing. This also helps in overriding API clients with stubs for the development or staging environment. See the example at Provider overriding.

If you need to inject not the whole object but the parts see Injecting provided object attributes, items, or call its methods.

To create a new provider see Creating a custom provider.

Providers module API docs - dependency_injector.providers

• Factory provider
  • Passing arguments to the underlying providers
  • Passing providers to the objects
  • String imports
  • Specializing the provided type
  • Abstract factory
  • Factory aggregate
• Singleton provider
  • Resetting memorized object
  • Using singleton with multiple threads
  • Implementing scopes
• Callable provider
• Coroutine provider
• Object provider
• List provider
• Dict provider
• Configuration provider
  • Loading from an INI file
  • Loading from a YAML file
  • Loading from a JSON file
  • Loading from a Pydantic settings
  • Loading from a dictionary
  • Loading from an environment variable
  • Loading a value
  • Loading from the multiple sources
  • Using environment variables in configuration files
  • Mandatory and optional sources
  • Specifying the value type
  • Strict mode and required options
  • Aliases
  • Injecting invariants
• Resource provider
  • Function initializer
  • Generator initializer
  • Subclass initializer
  • Resources, wiring, and per-function execution scope
  • Asynchronous initializers
• Aggregate provider
• Selector provider
• Dependency provider
• Provider overriding
• Injecting provided object attributes, items, or call its methods
• Injecting container “self”
• Creating a custom provider
• Asynchronous injections
  • Overriding behaviour
  • Async mode mechanics and API
• Typing and mypy