Week 1：作业2

#coding=utf-8
#Version:python3.6.0
#Tools:Pycharm 2017.3.2
__date__ = '2018/9/10 10:14'
__author__ = 'Steven'

'''
作业三：多级菜单
三级菜单
可依次选择进入各子菜单
所需新知识点：列表、字典
'''

class Location(object):
    def __init__(self, index = 0xFF, name = '', level = 0xFF, parent_index = 0xFF, child_node_num = 0):
        self.index = index
        self.name = name

        self.level = level
        self.parent_index = parent_index

        self.child_node_num = child_node_num

    def _append_to_parent(self, par_node):
        if self.index == 0xFF or self.name == '':
            print("Error: imcomplete location property !")
            return 0xFF
        if self.level != par_node.level + 1:
            print("Error: Invalid parent node !")
            return 0xFF
        self.parent_index = par_node.index
        par_node.child_node_num += 1
        return 0

effective_choice_flag = 0
loc_list = [[Location() for i in range(100)] for j in range(4)] #最多支持4级菜单,每级100个选项
cur_cls = 0xFF
node_idx = [0, 0, 0, 0]
with open('Menu_Data.txt', 'r', encoding='UTF-8') as menu_file_content:
    for line in menu_file_content:
        split_line = line.split()

        if int(split_line[0]) < 1 or int(split_line[0]) > 4:
            print("Fatal error: invalid class level !")
            effective_choice_flag = 0xFF
            break
        cur_cls = int(split_line[0]) - 1
        cur_loc = Location(node_idx[cur_cls], str(split_line[1]), cur_cls)
        if cur_cls > 0:
            if 0xFF == cur_loc._append_to_parent(loc_list[cur_cls-1][node_idx[cur_cls-1]-1]):
                effective_choice_flag = 0xFF
        loc_list[cur_cls][node_idx[cur_cls]] = cur_loc
        node_idx[cur_cls] += 1

user_choice = [0xFF,0xFF, 0xFF, 0xFF]
cls_name = ["Nation","Province/State", "City", "District"]
print("Welcome to delivery system !")

cur_cls = 0
while 1:
    if cur_cls >= 4:
        break
    print("Please choose the destination ", cls_name[cur_cls], " :")
    temp_idx = 0
    effective_idx = [0xFF for i in range(100)]
    for cur_idx in range(node_idx[cur_cls]):
        if cur_cls > 0 and loc_list[cur_cls][cur_idx].parent_index != loc_list[cur_cls - 1][user_choice[cur_cls - 1]].index:
            continue
        effective_idx[temp_idx] = cur_idx
        print("{loc_id}.{loc_name}".format(loc_id = temp_idx, loc_name = loc_list[cur_cls][cur_idx].name))
        temp_idx += 1

    if temp_idx > 0:
        if cur_cls > 0:
            print("999.Return to the superior menu")
        cur_choice = int(input("Choose your location Id:"))
        if 999 == cur_choice:
            if cur_cls > 0:
                cur_cls -= 2
            else:
                effective_choice_flag = 0xff
        elif cur_choice >=0 and cur_choice < temp_idx:
            user_choice[cur_cls] = effective_idx[cur_choice]
        else:
            print("Error: input out of range !")
            effective_choice_flag = 0xff
            break
    else:
        print("Oops, no effective option!")
        break
    cur_cls += 1

if 0 == effective_choice_flag:
    print("Please confirm: you have choosen {nation}{province}{city}{district} as your destination".
          format(nation = loc_list[0][user_choice[0]].name if user_choice[0] < 100 and loc_list[0][user_choice[0]].index != 0xFF else '',
                 province = loc_list[1][user_choice[1]].name if user_choice[1] < 100 and loc_list[1][user_choice[2]].index != 0xFF else '',
                 city = loc_list[2][user_choice[2]].name if user_choice[2] < 100 and loc_list[2][user_choice[2]].index != 0xFF else '',
                 district =loc_list[3][user_choice[3]].name if user_choice[3] < 100 and loc_list[3][user_choice[3]].index != 0xFF else ''))

文件内容：

1 中国
2 上海市
3 浦东新区
3 徐汇区
3 杨浦区
2 广东省
3 深圳市
4 龙岗区
4 南山区
4 福田区
3 广州市
4 番禹区
4 白云区
4 花都区
1 美国
2 加利福利亚州
3 旧金山市
3 洛杉矶市
2 德克萨斯州
3 休斯顿市
3 奥斯汀市