ext_flag = False# file = open("menu",'r',encoding='utf-8')    # 打开3级菜单文本文件# f = file.read()with open('menu','r',encoding='utf-8') as aff:  # 打开3级菜单文本文件    f= aff.read()for line in f:          # 读取文件中每行信息    file_str = str(f)    # 将每行信息转成字符串格式now_layers = eval(file_str)    # 字符串转成字典格式last_layers = [now_layers]      #把字典转成列表# print(now_layers)# print(last_layers)while not ext_flag:    for key in now_layers:        print(key)    choice = input('>>:').strip()    if len(choice) == 0: continue    if choice in now_layers:        last_layers.append(now_layers)        now_layers =now_layers[choice]    if choice =='b':        if last_layers:            now_layers=last_layers[-1]            last_layers.pop()    if choice == 'q':        ext_flag = True

menu文件内容

 

{

'浙江':{

'杭州':{

'西湖':{

'西溪',

'三墩'},

'滨江':{'滨和':{}, '高新':{}}

},

'丽水':{

'龙泉':{'宝剑':{}, '瓷器':{}},

'青田':{'石雕':{}, '华侨':{}},

'缙云':{'烧饼':{}, '木雕':{}},

},

},

'山东':{

'烟台':{'大海':{}, '日照':{}},

'青岛':{'平度':{}, '黄岛':{}},

'东营':{'利津', '垦利'}

},

'广东':{

'深圳':{'南山':{}, '福田':{}},

'梅州':{'五华':{}, '兴宁':{}},

'佛山':{'三水':{}, '桂城':{}}

}

}