def str2tuple(string, sep=","):
    """
    Map "1.0,2,0" => (1.0, 2.0)
    """
    tokens = string.split(sep)
    # if len(tokens) == 1:
    #     raise ValueError("Get only one token by " +
    #                      f"sep={sep}, string={string}")
    floats = map(float, tokens)
    return tuple(floats)