from typing import List


def _open_target_file(target_fn: str) -> List[List[float]]:
    """
    Args:
        target_fn (str): filename/path for target values file

    Returns:
        list[list[float]]: lists of target values, in preparation for torch.tensor of shape
            (n_targets, 1)
    """

    with open(target_fn, 'r') as tar_file:
        target = tar_file.readlines()
    tar_file.close()
    target = [[float(t.replace('\n', ''))] for t in target]
    return target