递归函数

def foo(n):
    print(n)
    n += 1
    foo(n)
foo(1)

import sys
print(sys.setrecursionlimit(100000))

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‘: {},}

def threeLM(dic):
    while True:
        for k in dic:print(k)
        key = input(‘input>>‘).strip()
        if key == ‘b‘ or key == ‘q‘:return key
        elif key in dic.keys() and dic[key]:
            ret = threeLM(dic[key])
            if ret == ‘q‘: return ‘q‘

threeLM(menu)