3级菜单的另一种实现方式：循环
函数的方式：http://www.cnblogs.com/jailly/p/6709573.html
1.先创建一个能够表明3级目录结构之间映射关系的字典，然后将其存入一个pickle文件以便调用
1 import pickle 2 3 dir_windows = ['explorer.exe'] 4 part_C = {'windows': dir_windows} 5 6 dir_setup = ['rhel-7.3.iso', 'SecureCRT6.rar'] 7 dir_program = ['putty.exe', 'PhotoshopCC2016.exe'] 8 part_D = {'setup': dir_setup, 'program': dir_program} 9 10 dir_video = ['君の名は.mp4'] 11 dir_game = ['NieR: Automata', 'Sid Meier\'s Civilization VI'] 12 part_E = {'video': dir_video, 'game': dir_game} 13 14 root = {'C': part_C, 'D': part_D, 'E': part_E} 15 16 with open('dir.pkl','wb') as f: 17 pickle.dump(root,f)
2.主程序
1 #! /usr/bin/env python3 2 # -*- coding:utf-8 -*- 3 # Author:Jailly 4 5 ''' 6 以3级的目录结构模拟三级菜单，目录结构如下：： 7 C 8 windows 9 explorer.exe 10 D 11 setup 12 rhel-7.3.iso 13 SecureCRT6.rar 14 program 15 putty.exe 16 PhotoshopCC2016.exe 17 E 18 video 19 君の名は.mp4 20 game 21 NieR: Automata 22 Sid Meier's Civilization VI 23 ''' 24 25 import pickle 26 27 def main(root): 28 n = 1 29 select1 = None 30 select2 = None 31 select3 = None 32 33 while n: 34 if n == 1: 35 if not select1: 36 print('欢迎进入%d级目录，该目录下有如下目录/文件：%s'% (n,'、'.join(sorted(root.keys())))) 37 select1 = input('请选择您想要执行的操作：(“[目录名]”：进入目录；“q”：退出)：') 38 39 if select1 in root: 40 n = 2 41 continue 42 elif select1 == 'q': 43 break 44 else: 45 select1 = input('指令输入错误，请重新输入:') 46 continue 47 48 elif n == 2: 49 if not select2: 50 print('欢迎进入%d级目录，该目录下有如下目录/文件：%s'%(n,'、'.join(sorted(root[select1].keys())))) 51 select2 = input('请选择您想要执行的操作：(“[目录名]”：进入目录；“b”，返回上一级；“q”：退出)：') 52 53 if select2 in root[select1]: 54 n = 3 55 continue 56 elif select2 == 'b': 57 n = 1 58 continue 59 elif select2 == 'q': 60 break 61 else: 62 select2 = input('指令输入错误，请重新输入：') 63 continue 64 65 elif n == 3: 66 if not select3: 67 print('欢迎进入%d级目录，该目录下有如下目录/文件：%s' % (n, '、'.join(sorted(root[select1][select2])))) 68 select3 = input('请选择您想要执行的操作：(“b”，返回上一级；“q”：退出)：') 69 70 if select3 == 'b': 71 n = 2 72 continue 73 elif select3 == 'q': 74 break 75 else: 76 select3 = input('指令输入错误，请重新输入：') 77 continue 78 79 if __name__ == '__main__': 80 81 with open('dir.pkl', 'br') as f: 82 root = pickle.load(f) 83 84 main(root)