#
Using the Python API

Lighteval can be used from a custom Python script. To evaluate a model, you will need to set up an EvaluationTracker, PipelineParameters, a `model` or a `model_config`, and a Pipeline.

After that, simply run the pipeline and save the results.

    import lighteval
    from lighteval.logging.evaluation_tracker import EvaluationTracker
    from lighteval.models.vllm.vllm_model import VLLMModelConfig
    from lighteval.pipeline import ParallelismManager, Pipeline, PipelineParameters
    from lighteval.utils.imports import is_package_available

    if is_package_available("accelerate"):
        from datetime import timedelta
        from accelerate import Accelerator, InitProcessGroupKwargs
        accelerator = Accelerator(kwargs_handlers=[InitProcessGroupKwargs(timeout=timedelta(seconds=3000))])
    else:
        accelerator = None

    def main():
        evaluation_tracker = EvaluationTracker(
            output_dir="./results",
            save_details=True,
            push_to_hub=True,
            hub_results_org="your_username",  # Replace with your actual username
        )

        pipeline_params = PipelineParameters(
            launcher_type=ParallelismManager.ACCELERATE,
            custom_tasks_directory=None,  # Set to path if using custom tasks
            # Remove the parameter below once your configuration is tested
            max_samples=10
        )

        model_config = VLLMModelConfig(
            model_name="HuggingFaceH4/zephyr-7b-beta",
            dtype="float16",
        )

        task = "lighteval|gsm8k|5"

        pipeline = Pipeline(
            tasks=task,
            pipeline_parameters=pipeline_params,
            evaluation_tracker=evaluation_tracker,
            model_config=model_config,
        )

        pipeline.evaluate()
        pipeline.save_and_push_results()
        pipeline.show_results()

    if __name__ == "__main__":
        main()

##
Key Components

###
EvaluationTracker

The `EvaluationTracker` handles logging and saving evaluation results. It can save results locally and optionally push them to the Hugging Face Hub.

###
PipelineParameters

`PipelineParameters` configures how the evaluation pipeline runs, including parallelism settings and task configuration.

###
Model Configuration

Model configurations define the model to be evaluated, including the model name, data type, and other model-specific parameters. Different backends (VLLM, Transformers, etc.) have their own configuration classes.

###
Pipeline

The `Pipeline` orchestrates the entire evaluation process, taking the tasks, model configuration, and parameters to run the evaluation.

##
Running Multiple Tasks

You can evaluate on multiple tasks by providing a comma-separated list or a file path:

    # Multiple tasks as comma-separated string
    tasks = "lighteval|aime24|0,lighteval|aime25|0"

    # Or load from a file
    tasks = "./path/to/tasks.txt"

    pipeline = Pipeline(
        tasks=tasks,
        # ... other parameters
    )

##
Custom Tasks

To use custom tasks, set the `custom_tasks_directory` parameter to the path containing your custom task definitions:

    pipeline_params = PipelineParameters(
        custom_tasks_directory="./path/to/custom/tasks",
        # ... other parameters
    )

For more information on creating custom tasks, see the Adding a Custom Task guide.

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