def make_name(model, passed_name=None, ending=None):
    """Determine name of file to be created."""
    if passed_name == None:
        file_name = model.split('.')[0] + ending
    elif len(passed_name.split('.')) > 1:
        file_name = passed_name
    else:
        file_name = passed_name + ending
    return file_name
