[OPIK-573] Implement get_experiment_by_[name, id] and implement Experiment.get_items()

[alexkuzmik]

Details

Access to existing experiment

It is now possible to get Experiment instance for an experiment that already exists.

client = Opik()
experiment = client.get_experiment_by_name("my-experiment-123")
# or 
experiment = client.get_experiment_by_id("...")

Experiment methods updates

1. A signature to experiment.insert has been changed to:

def insert(
    self,
    experiment_items_references: List[ExperimentItemReferences],
)

where ExperimentItemReferences is a dataclass

@dataclasses.dataclass
class ExperimentItemReferences:
    dataset_item_id: str
    trace_id: str

It emphasizes that experiment items are essentialy just dataset items and traces linked together, and it is not possible to create an experiment item by manually specifying its content.

2. A new method was added - experiment.get_items(). It returns a list of ExperimentItemContent objects.

@dataclasses.dataclass
class ExperimentItemContent:
    id: str
    dataset_item_id: str
    trace_id: str
    dataset_item_data: Optional[Dict[str, Any]]
    evaluation_task_output: Optional[Dict[str, Any]]
    feedback_scores: List[FeedbackScoreDict]

New names in the opik namespace

ExperimentItemReferences and ExperimentItemContent were added to opik.__all__ list.

Issues

Resolves (#851)

Testing

Unit tests and e2e tests were updated.

Documentation

Docstrings added.

[jverre]

Hi @alexkuzmik

Can we update the definition for ExperimentItemContent to align more with the UI:

• input -> dataset_item_data
• output -> evaluation_task_output