Python自动化开发学习之三级菜单制作

data = {
 "天津":{
  "南开区":{
   "南开大学":{
    "历史系":{},"文学系":{},"英语系":{},},"科技大学":{
    "计算机系":{},"机器系":{},"软件系":{},"理工大学":{
    "数学系":{},"化学系":{},"物理系":{},"武清区":{
   "武清大学":{
    "历史系":{},"武清科技大学":{
    "计算机系":{},"武清理工大学":{
    "数学系":{},"北辰区":{
   "北辰大学":{
    "历史系":{},"北辰科技大学":{
    "计算机系":{},"北辰理工大学":{
    "数学系":{},"河北":{
  "保定市": {
   "保定大学": {
    "历史系": {},"文学系": {},"英语系": {},"保定科技大学": {
    "计算机系": {},"机器系": {},"软件系": {},"保定理工大学": {
    "数学系": {},"化学系": {},"物理系": {},"秦皇岛": {
   "秦皇岛大学": {
    "历史系": {},"秦皇岛科技大学": {
    "计算机系": {},"秦皇岛理工大学": {
    "数学系": {},"石家庄": {
   "石家庄大学": {
    "历史系": {},"石家庄科技大学": {
    "计算机系": {},"石家庄理工大学": {
    "数学系": {},"河南":{
  "郑州市": {
   "郑州大学": {
    "历史系": {},"郑州科技大学": {
    "计算机系": {},"郑州理工大学": {
    "数学系": {},"南阳市": {
   "南阳大学": {
    "历史系": {},"南阳科技大学": {
    "计算机系": {},"南阳理工大学": {
    "数学系": {},"登封市": {
   "登封大学": {
    "历史系": {},"登封科技大学": {
    "计算机系": {},"登封理工大学": {
    "数学系": {},}
#exit_flag = False
while True:
 for i in data :
  print (i)
 choice = input ("input:")
 if choice in data:
  while True:
   for i2 in data[choice]:
    print (i2)
   choice2 = input("input2:")
   if choice2 in data[choice]:
    while True:
     for i3 in data[choice][choice2]:
      print (i3)
     choice3 = input("input3:")
     if choice3 in data[choice][choice2]:
      for i4 in data[choice][choice2][choice3]:
       print(i4)
      choice4 = input("Press b to return to the previous level:")
      if choice4 == "b":
       pass
      elif choice4 == "q":
       exit ()
     if choice3 == "b":
      break
     elif choice3 == "q":
      exit()
   if choice2 == "b":
    break
   elif choice2 == "q":
    exit()