【代码段】-- 三级菜单 (基础版)

# __author__:"ShengXin"
# __date__:2017/8/24
full_menu = {‘河北省‘:{‘张家口市‘:[‘蔚县‘,‘涿鹿县‘,‘怀来县‘,‘阳原县‘],
                        ‘唐山市‘:[‘丰润区‘,‘滦县‘,‘开平区‘,‘玉田县‘],
                        ‘衡水市‘:[‘武邑县‘,‘武强县‘,‘枣强县‘,‘市辖区‘]
                        },
             ‘山西省‘:{‘太原市‘:[‘A‘,‘B‘,‘C‘,‘D‘],
                        ‘大同市‘:[‘AA‘,‘BB‘,‘CC‘,‘DD‘],
                        ‘吕梁市‘:[‘AAA‘,‘BBB‘,‘CCC‘,‘DDD‘]
                        },
             ‘河南省‘:{‘郑州市‘:[‘W‘,‘E‘,‘R‘,‘T‘],
                        ‘开封市‘:[‘WW‘,‘EE‘,‘RR‘,‘TT‘],
                        ‘洛阳市‘:[‘WWW‘,‘EEE‘,‘RRR‘,‘TTT‘]
                         }
             }
town = []
county = []
flag_one = True
while flag_one:
    flag_two = True
    print("欢迎来到德莱联盟，请选择您想加入的省：".center(30,"-"))
    for i in full_menu:   #遍历键
        print(i)
    choose = input("您选择：")
    if choose in full_menu:
        while flag_two:
            print("%s".center(30,"-")%choose)
            for j in full_menu[choose]:  #市区
                print(j)
                town.append(j)
            flag_two = True
            flag_three =True
            small_choose = input("选择您感兴趣的市,b返回，q退出")
            if small_choose in town:
                while flag_three:
                    print("%s".center(30,"-")%small_choose)
                    hah = ((full_menu[choose])[small_choose])
                    for e in hah:
                        print(e)
                        county.append(e)
                    flag_three =True
                    flag_four = True
                    least_choose = input("请选择您喜欢的县，b返回，q退出")
                    if least_choose in county:
                        while flag_four:
                            flag_four =True
                            print("\n"+least_choose+"欢迎您")
                            man = input("您可按b继续选择县，按q选择市，按w退出")
                            if man == "b":
                                flag_four =False
                            elif man == "q":
                                flag_four = False
                                flag_three = False
                            elif man == "w":
                                flag_four = False
                                flag_three = False
                                flag_two = False
                    if least_choose == "b":
                        break
                    elif least_choose == "q":
                        flag_two =False
                        break
                    elif least_choose == "w":
                        flag_one =False
                        flag_two =False
                        break
            elif small_choose == "b":
                break
            elif small_choose == "q":
                flag_two = False
            else:
                print("请重新输入,或按b返回")
    elif choose == "q":
        print("再见")
        flag_one = False
    else:
         print("请重新输入,或按q退出")