Depends

Dependency

Bases: Generic[T]

Represents a dependency wrapping a callable that returns a value of type T.

Attributes:

Name	Type	Description
callable	Callable[..., T]	The callable that provides the dependency.

__init__(callable)

Initializes the dependency with the provided callable.

Parameters:

Name	Type	Description	Default
callable	Callable[..., T]	The callable to wrap as a dependency.	required

Provider

Manages dependency overrides for dependency injection.

Attributes:

Name	Type	Description
dependency_overrides	dict	A mapping of original dependencies to their overrides.

__init__()

Initializes an empty dictionary for dependency overrides.

override(dependency, override)

Overrides a given dependency with a new callable.

Parameters:

Name	Type	Description	Default
dependency	Callable	The original dependency to override.	required
override	Callable	The new callable to use instead of the original.	required

Depends(callable)

Creates a Dependency instance wrapping the given callable.

Parameters:

Name	Type	Description	Default
callable	Callable	The callable to wrap as a dependency.	required

Returns:

Name	Type	Description
Dependency	Dependency	An instance of Dependency wrapping the callable.

Example

provider = Provider()

def get_session() -> Session: ...

@inject(provider) def add_user(user: dict, session: Session = Depends(get_session)): ...

@inject(provider) def mypy_comp_add_user(user: dict, session: Dependency[Session] = Depends(get_session)): ...

inject(provider)

Decorator to inject dependencies into a function based on a provider.

This decorator supports both synchronous and asynchronous functions. It resolves dependencies using the provided provider, manages the context with an exit stack, and calls the original function with the injected arguments.

Parameters:

Name	Type	Description	Default
provider	Provider	An instance responsible for providing dependencies.	required

Returns:

Name	Type	Description
Callable	Callable	A decorator that wraps the target function, injecting dependencies.

Examples:

provider = Provider()

def get_session() -> Session:
    ...

@inject(provider)
def add_user(user: dict, session: Session = Depends(get_session)):
    ...