def is_set(tdict, path):
    """

    :param tdict: a dictionary representing a argument tree
    :param path: a path list
    :return: True/False if the value is set
    """
    t = tdict
    for step in path:
        try:
            t = t[step]
        except KeyError:
            return False

    if t is not None:
        return True

    return False