52-python-三级菜单

menu = {
    '北京': {
        '海淀': {
            '五道口': {
                'soho': {},
                '网易': {},
                'google': {}
            },
            '中关村': {
                '爱奇艺': {},
                '汽车之家': {},
                'youku': {},
            },
            '上地': {
                '百度': {},
            },
        },
        '昌平': {
            '沙河': {
                '老男孩': {},
                '北航': {},
            },
            '天通苑': {},
            '回龙观': {},
        },
        '朝阳': {},
        '东城': {},
    },
    '上海': {
        '闵行': {
            "人民广场": {
                '炸鸡店': {}
            }
        },
        '闸北': {
            '火车战': {
                '携程': {}
            }
        },
        '浦东': {},
    },
    '山东': {},
}
l = [menu]

while l:
    for i in l[-1]:print(i)
    q = input('<<<')
    if q in l[-1].keys() and l[-1][q]:
        l.append(l[-1][q])
    elif q == 'b':l.pop()
    elif q == 'q':break



def fn(dic):
    while True:
        for key in dic: print(key)
        name = input("<<<").strip()
        if name == 'b' or name == 'q':return name 
        elif name in dic.keys() or dic[name]:
            ret = fn(dic[name])
            if ret == 'q': return 'q'
fn(menu)