test_json_distance_evaluator_evaluate_strings_custom_operator_equal() — langchain Function Reference

Source Code

libs/langchain/tests/unit_tests/evaluation/parsing/test_json_distance.py lines 113–123

def test_json_distance_evaluator_evaluate_strings_custom_operator_equal() -> None:
    """Custom operator that returns 0.5 if strings are different."""

    def custom_distance(a: str, b: str) -> float:
        return 0.5 if a != b else 0.0

    evaluator = JsonEditDistanceEvaluator(string_distance=custom_distance)
    prediction = '{"a": "apple", "b": "banana"}'
    reference = '{"a": "apple", "b": "berries"}'
    result = evaluator._evaluate_strings(prediction=prediction, reference=reference)
    assert result["score"] == 0.5