def trim_column(data_column, max_length):
    """
    Abstraction of numpy slicing operation for single column truncation.
    :param data_column: 1D np.array
    :param max_length: int of truncation index
    :return: np.array
    """
    assert (len(data_column.shape) == 1)  # Assert data_column is a 1D numpy array
    return data_column[:max_length]