python学习之路 三级菜单的实现

三级菜单实现的几种方式

普通的写法

name = {
    '北京': {
        '朝阳区': {
            '望京': ['cc', '大众'],
            '国贸': ['宝马', '奔驰'],
            '东直门': ['保洁', '业务'],
        },
        '海淀区': {

        },
        '昌平区': {
            '沙河': ['默默', 'qq'],
            '天通苑': ['tim', 'time'],
        },

    },
    '安徽': {},
    '湖南': {},
}
var1 = 1
while var1:
    for i in name:
        print(i)
    print('''------温馨提示------
    退出请按"q",
    返回上一级请按"b"，
    返回首页请按"h"
--------------------''')
    while True:
        city_choose = input("选择1>>>")
        if city_choose in name:
            var2 = 1
            while var2:
                for i2 in name[city_choose]:
                    print('	', i2)
                city_choose1 = input("选择2>>>")
                if city_choose1 in name[city_choose]:
                    var3 = 1
                    while var3:
                        for i3 in name[city_choose][city_choose1]:
                            print('		', i3)
                        city_choose2 = input('选择我3>>>')
                        if city_choose2 in name[city_choose][city_choose1]:
                            var4 = 1
                            while var4:
                                for i4 in name[city_choose][city_choose1][city_choose2]:
                                    print('			', i4)
                                while True:
                                    chosee = input('已到最后一层，输入你的选择>>>')
                                    if chosee == 'q':
                                        exit()
                                    elif chosee == 'b':
                                        var4 = 0
                                        break
                                    elif chosee == 'h':
                                        var2 = var3 = var4 = 0
                                        break
                                    else:
                                        print('输入错误请重新输入:')
                        if city_choose2 == 'q':
                            exit()
                        elif city_choose2 == 'b':
                            var3 = 0
                            print('--------')
                        elif city_choose2 == 'h':
                            var3 = var2 = 0
                            print('--------')
                            for i in name:
                                print(i)
                if city_choose1 == 'q':
                    exit()
                elif city_choose1 == 'b':
                    var2 = 0
                    print('--------')
                    for i in name:
                        print(i)
                elif city_choose1 == 'h':
                    var2 = 0
                    print('--------')
                    for i in name:
                        print(i)
        if city_choose == 'q':
            exit()
        elif city_choose == 'b':
            print('已经是第一层，请重新选择')
            print('--------')
            for i in name:
                print(i)
        elif city_choose == 'h':
            print('已经是第一层，请重新选择')
            print('--------')
            for i in name:
                print(i)

递归函数实现三级菜单

menu = {
    '北京': {
        '海淀': {
            '五道口': {
                'soho': {},
                '网易': {},
                'google': {}
            },
            '中关村': {},
            '上地': {},
        },
        '昌平': {},
        '朝阳': {},
        '东城': {},
    },
    '安徽': {},
    '湖南': {},
}


def three_menu(dic):
    while True:
        for city in dic:
            print(city)
        choose = input(">>>").strip()
        if choose == 'b' or choose == 'q':
            return choose
        elif choose in dic.keys() and dic[choose]:
            ret = three_menu(dic[choose])
            if ret == 'q':
                return 'q'


three_menu(menu)

堆栈实现

menu = {
    '北京': {
        '海淀': {
            '五道口': {
                'soho': {},
                '网易': {},
                'google': {}
            },
            '中关村': {},
            '上地': {},
        },
        '昌平': {},
        '朝阳': {},
        '东城': {},
    },
    '安徽': {},
    '湖南': {},
}

l = [menu]
while True:
    if not l: # 如果列表为空就直接退出
        break
    for city in l[-1]:  # 显示最后一个元素的内容
        print(city)
    choose = input(">>>").strip()
    if choose == 'b':
        l.pop()  # 要显示上一层信息就要把这一层信息从列表中删除，每次显示的信息都是最后一个元素
    elif choose.lower() == 'q':
        break
    elif choose in l[-1].keys() and l[-1][choose]:
        l.append(l[-1][choose])  # 把最新的内容加到列表最后面