day3-三级目录

date = {"guangdong":{"guangzhou":{"tianhe":["tyx","zjxc"],
 "panyu":["a","b"]},
 "maoming":{},
 "zhongshan":{}},
 "henan":{"jiaozuo":{"boai":["nan","bei"],
 "wen":["c","d"]},
 "zhengzhou":{},
 "luoyang":{}},
 "shandong":{"jinan":{},
 "qingdao":{}}}
exit_flag = True
while exit_flag:
 for i in date:
 print(i)
 choice = input("please choose")
 if choice in date:
 while exit_flag:
 for i2 in date[choice]:
 print(i2)
 choice2 = input("please choose2")
 if choice2 in date[choice]:
 while exit_flag:
 for i3 in date[choice][choice2]:
 print(i3)
 choice3 = input("please choose3")
 if choice3 in date[choice][choice2]:
 for i4 in date[choice][choice2][choice3]:
 print(i4)
 choice4 = input("Ending!Return please press 'b'.")
 if choice4 == "b":
 pass
 elif choice4 == "q":
 exit_flag = False
 if choice3 == "b":
 break
 elif choice3 == "q":
 exit_flag = False
 if choice2 == "b":
 break
 elif choice2 == "q": 
 exit_flag = False