Python 2: Level 3 menu,

Python 2: Level 3 menu,

Level 3 menu requirements:

1. Run the program to output the first menu

2. Select a level-1 menu and output level-2 menus. Similarly, level-3 menus are output.

3. Save menu data in a file

4. Ask the user to select whether to exit

5. The function of returning the top menu

 

Program code:

#! /Usr/bin/env python
#-*-Coding: UTF-8 -*-

Menu = open('menu.txt ', encoding = 'utf-8') extract all place names at intervals from the menu.txt File
For j in menu. readlines (): # assign values to the variables corresponding to all place names.
Region, province_db, province_hb, city_hlj, city_jl, city_hb, city_sx, area_heb ,\
Area_jms, area_cc, area_jl, area_bd, area_sjz, area_ty, area_dt = j. split ('$ ')

Flag = True # Set the program termination variable
While flag: # enter the first-level menu to display the first-level menu content, waiting for the user to enter
Print ("select region: \ n (enter q to exit )")
Print (region)
Num = input ("----> ")
If num = '1': # judge user input. if the user selects the first menu, go to the following loop.
While flag: # enter the level-2 menu, display the level-2 menu content, waiting for the user to enter
Print ("select the province: \ n (enter B to return to the upper menu and enter q to exit )")
Print (province_db)
Num = input ("----> ")
If num = '1': # judge user input. if the user selects the first menu, go to the following loop.
While flag: # enter the Level 3 menu, display Level 3 menu content, waiting for user input
Print ("select the city: \ n (enter B to return to the upper menu and enter q to exit )")
Print (city_hlj)
Num = input ("----> ")
If num = '1': # determine whether the user selects the first menu and enter the following Loop
While flag: # display the content in level 3 menu
Print ('your City has the following districts: \ n % s' % (area_heb ))
Print ('enter B and return to the upper menu. Enter q to exit ')
Num = input ("----> ")
If num = 'B': # if the user enters "B", the system jumps out of the current loop and returns to the upper menu.
Break
Elif num = 'q': # If you enter "q", set the program termination variable to False to exit all loops and terminate the program.
Flag = False
Else: # other characters entered by the user. If the input is incorrect, enter another character.
Print ('input is incorrect. Please input \ n' again ')
Elif num = '2 ':
While flag:
Print ('your City has the following districts: \ n % s' % (area_jms ))
Print ('enter B and return to the upper menu. Enter q to exit ')
Num = input ("----> ")
If num = 'B ':
Break
Elif num = 'q ':
Flag = False
Else:
Print ('input is incorrect. Please input \ n' again ')
Elif num = 'B ':
Break
Elif num = 'q ':
Flag = False
Else:
Print ('input is incorrect. Please input \ n' again ')
Elif num = '2 ':
While flag:
Print ("select the city: \ n (enter B to return to the upper menu and enter q to exit )")
Print (city_jl)
Num = input ("----> ")
If num = '1 ':
While flag:
Print ('your City has the following districts: \ n % s' % (area_cc ))
Print ('enter B and return to the upper menu. Enter q to exit ')
Num = input ("----> ")
If num = 'B ':
Break
Elif num = 'q ':
Flag = False
Else:
Print ('input is incorrect. Please input \ n' again ')
Elif num = '2 ':
While flag:
Print ('your City has the following districts: \ n % s' % (area_jl ))
Print ('enter B and return to the upper menu. Enter q to exit ')
Num = input ("----> ")
If num = 'B ':
Break
Elif num = 'q ':
Flag = False
Else:
Print ('input is incorrect. Please input \ n' again ')
Elif num = 'B ':
Break
Elif num = 'q ':
Flag = False
Else:
Print ('input is incorrect. Please input \ n' again ')
Elif num = 'B ':
Break
Elif num = 'q ':
Flag = False
Else:
Print ('input is incorrect. Please input \ n' again ')

Elif num = '2 ':
While flag:
Print ("select the province: \ n (enter B to return to the upper menu and enter q to exit )")
Print (province_hb)
Num = input ("----> ")
If num = '1 ':
While flag:
Print ("select the city: \ n (enter B to return to the upper menu and enter q to exit )")
Print (city_hb)
Num = input ("----> ")
If num = '1 ':
While flag:
Print ('your City has the following districts: \ n % s' % (area_bd ))
Print ('enter B and return to the upper menu. Enter q to exit ')
Num = input ("----> ")
If num = 'B ':
Break
Elif num = 'q ':
Flag = False
Else:
Print ('input is incorrect. Please input \ n' again ')
Elif num = '2 ':
While flag:
Print ('your City has the following districts: \ n % s' % (area_sjz ))
Print ('enter B and return to the upper menu. Enter q to exit ')
Num = input ("----> ")
If num = 'B ':
Break
Elif num = 'q ':
Flag = False
Else:
Print ('input is incorrect. Please input \ n' again ')
Elif num = 'B ':
Break
Elif num = 'q ':
Flag = False
Else:
Print ('input is incorrect. Please input \ n' again ')
Elif num = '2 ':
While flag:
Print ("select the city: \ n (enter B to return to the upper menu and enter q to exit )")
Print (city_sx)
Num = input ("----> ")
If num = '1 ':
While flag:
Print ('your City has the following districts: \ n % s' % (area_ty ))
Print ('enter B and return to the upper menu. Enter q to exit ')
Num = input ("----> ")
If num = 'B ':
Break
Elif num = 'q ':
Flag = False
Else:
Print ('input is incorrect. Please input \ n' again ')
Elif num = '2 ':
While flag:
Print ('your City has the following districts: \ n % s' % (area_dt ))
Print ('enter B and return to the upper menu. Enter q to exit ')
Num = input ("----> ")
If num = 'B ':
Break
Elif num = 'q ':
Flag = False
Else:
Print ('input is incorrect. Please input \ n' again ')
Elif num = 'B ':
Break
Elif num = 'q ':
Flag = False
Else:
Print ('input is incorrect. Please input \ n' again ')
Elif num = 'B ':
Break
Elif num = 'q ':
Flag = False
Else:
Print ('input is incorrect. Please input \ n' again ')
Elif num = 'q ':
Flag = False
Else:
Print ('input is incorrect. Please input \ n' again ')

Menu. close ()


Menu file:

1. Northeast Region 2, North China region $1, Heilongjiang Province 2, Jilin province $1, Hebei 2, Shanxi $1, Harbin 2, Jiamusi city $1, Changchun 2, Jilin City $1, baoding City 2, Shijiazhuang city $1, Taiyuan City 2, Datong City $1, daoli District 2, Nangang district $1, Qianjin District 2, Xiangyang district $1, nanguan District 2, Kuan Cheng District $1, chuanying District 2, longtan district $1, jingxiu District 2, lianchi district $1, Xinhua District 2, Chang 'an district $1, xiaodian District 2, Yingze district $1, South Suburb 2, xinrong District

Important Position of the program:

1,
Menu = open('menu.txt ', encoding = 'utf-8') # The decoder must be specified because the menu file contains Chinese characters.
For j in menu. readlines (): # Use "$" in the file as a flag to split the file and assign the file content to the corresponding variables.
Region, province_db, province_hb, city_hlj, city_jl, city_hb, city_sx, area_heb ,\
Area_jms, area_cc, area_jl, area_bd, area_sjz, area_ty, area_dt = j. split ('$ ')

2,

If num = 'B': # if you enter B
Break # Jump out of this loop
Elif num = 'q': # If you enter q
Flag = False # Set flag to Flase, so that all while loop values become False and the program is terminated.


Program running error explanation:

This error is a decoding error when retrieving data from the file. Because the file contains Chinese characters, you need to add the encoding = 'utf-8' parameter when reading the file.