di_container

Classes:

• CircularDependencyError –

  Raised when dependency resolution encounters a reference cycle.

• DiContainer –

  A lightweight configuration-based Dependency Injection (DI) container.

CircularDependencyError

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Raised when dependency resolution encounters a reference cycle.

DiContainer

DiContainer(registry: dict[str, Any])

A lightweight configuration-based Dependency Injection (DI) container.

The container receives a fully-parsed configuration dictionary (after environment-variable substitution via load_config()) and provides objects based on _target_ class paths.

Features

• Supports _scope_ = "singleton" (default) or "prototype".
• _target_ is required for every component.
  • String values starting with @ are treated as dependency references.
• Keys starting with "_" (e.g., _target_, _scope_) are metadata and excluded from constructor arguments.
• Uses Python's importlib to dynamically import target classes.
• Singleton instances are cached inside the container.

Example YAML:

job_fetcher:
  _target_: oqtopus_engine_core.fetchers.OqtopusCloudJobFetcher
  _scope_: singleton
            repo: "@job_repo"

        job_repo:
            _target_: oqtopus_engine_core.repositories.JobRepository
            base_url: "http://localhost:8888"

Example usage:

dicon = DiContainer(registry_config)
job_fetcher = dicon.get("job_fetcher")

Parameters:

• registry

  (dict[str, Any]) –

  Configuration dictionary for the dependency registry. Top-level keys represent dependency names.

Methods:

• get –

  Retrieve a dependency by name.

get

get(name: str) -> Any

Retrieve a dependency by name.

Behavior

• Raise KeyError if the name does not exist in the config.
• Import the target class defined by _target_.
• Create an instance with kwargs from the component config.
• Respect _scope_:
  • singleton (default): cache the instance
  • prototype: always create a fresh instance

Parameters:

• name

  (str) –

  Component name to retrieve.

Returns:

• Any –

  The created or cached instance.

Raises:

• KeyError –

  If the component name is missing.

• ValueError –

  If _target_ is missing.

• CircularDependencyError –

  If dependency references form a cycle.

• ImportError –

  If module/class cannot be imported.

• TypeError –

  If constructor arguments mismatch.