the MENU = { ' Beijing ' : { ' Haidian ' : { ' Wudaokou ' : { ' SOHO ' : {}, ' NetEase ' : {}, ' Google ' : {} }, ' Zhongguancun ' : { ' iQIYI ' : {}, ' car home ' : {}, ' the youku ' : {} }, 'On the ground ' : { ' Baidu ' : {} } }, ' Changping ' : { ' River ' : { ' Old Boy ' : {}, ' Northern ' : {} }, ' Tiantongyuan ' : {}, ' Huilongguan ' : {} }, ' sun ' : {}, ' East ' : {} }, 'Shanghai ': { " Minhang " : { " People's Square " : { ' Fried Chicken ' : {} } }, ' Zhabei ' : { ' Train war ' : { ' Ctrip ' : {} } }, ' Pudong ' : {} , }, ' Shandong ' : {} } # DEF show_menu (MENU): # the while True: # for K in MENU: # print(k) # inp = input(">>>>").strip() # if inp.upper() == 'B': # break # elif menu.get(inp): # con = menu[inp] # show_menu(con) # # show_menu(menu) while 1: lis = [menu] for k in lis[-1]: print(k) inp = input('>>>>') # print(menu[inp]) lis.append(lis[-1][inp])