def nested_simplify(obj, decimals=3):
    """
    Simplifies an object by rounding float numbers, and downcasting tensors/numpy arrays to get simple equality test
    within tests.
    """
    import numpy as np

    if isinstance(obj, list):
        return [nested_simplify(item, decimals) for item in obj]
    if isinstance(obj, tuple):
        return tuple([nested_simplify(item, decimals) for item in obj])
    elif isinstance(obj, np.ndarray):
        return nested_simplify(obj.tolist())
    elif isinstance(obj, Mapping):
        return {nested_simplify(k, decimals): nested_simplify(v, decimals) for k, v in obj.items()}
    elif isinstance(obj, (str, int, np.int64)):
        return obj
    elif obj is None:
        return obj
    elif is_torch_available() and isinstance(obj, torch.Tensor):
        return nested_simplify(obj.tolist(), decimals)
    elif is_tf_available() and tf.is_tensor(obj):
        return nested_simplify(obj.numpy().tolist())
    elif isinstance(obj, float):
        return round(obj, decimals)
    elif isinstance(obj, (np.int32, np.float32)):
        return nested_simplify(obj.item(), decimals)
    else:
        raise Exception(f"Not supported: {type(obj)}")

    Simplifies an object by rounding float numbers, and downcasting tensors/numpy arrays to get simple equality test
    within tests.
    
dpkd/transformers/src/transformers/testing_utils.py