def list_sum_recursion(num_list):
    """
    计算整数列表的总和
    使用递归解决
    eg:
        sum = (1 + (3 + (5 + (7 + 9))))
    """
    if len(num_list) == 1:
        return num_list[0]
    else:
        return num_list[0] + list_sum_recursion(num_list[1:])