def _input_fixer(image_columns, image_path):
    """
    This function turns image_columns into a list of a single element if there is only
    one image column. It also fixes the image path to contain a trailing `/` if the path to the
    directory is missing one.

    Parameters
    ----------
    image_columns : list
        A list of the image column headers

    image_path : str
        Path to the image directory
    """
    if isinstance(image_columns, str):
        image_columns = [image_columns]
    if image_path != '' and image_path[-1] != '/':
        image_path = '{}/'.format(image_path)
    return image_columns, image_path
