Dynamic user-created menus with sub-menus in a command line script

Question

Questions:

• How could this code be written better?
• Could this be written in less lines of code if constructed using classes?
• Also, If the user-created menu items were to be saved to a file for later use, which would be the best approach to use? (pickle? plain text file? etc.)

Problems:

• How do I dynamically draw the fixed menu items in the settings menu from a list or dict?
• How to make items selectable by number or a specific character?
• My main struggle came with dynamically displaying and executing sub-menu items.

---

Preface:

After about 3 weeks of research, trial and error, playing with different approaches and data structures, I ended up scrapping all my code and resigning myself to writing the following code.

This problem originated as a programming that challenged I created for myself and it now haunts me because I am having to admit defeat by asking you guys for guidance. This drives me crazy since I know there are probably very elegant ways of writing this script, but this was the only way I could make it work and produce the desired outputs.

I have spent hours researching stackoverflow and other sites for similar answers, but none fully addressed my particular design goals, such as dealing with sub-menus and the dynamic nature of this menu system.

I should also mention that I have not fully coded every aspect of this script, but there is enough here to allow the creation of menu items and demonstrate what i'm trying to achieve.

---

#!/usr/bin/python
import sys, os
menu_actions = {}
user_menu_items = []
def add_userItem(item):
 returnitem = "item " + item + " created..."
 return returnitem
def show_settings():
 os.system('clear')
 print "\nEdit"
 print "Default Settings"
 print "\nBack"
 choice = raw_input(" >> ")
 if choice.lower() == 'back':
 main_menu()
 else:
 decision(choice)
 return
def quit():
 raise SystemExit()
def s_edit():
 os.system('clear')
 print "\nCreate"
 print "Modify"
 print "\nBack\n"
 choice = raw_input(" >> ")
 if choice.lower() == 'back':
 show_settings()
 else:
 decision(choice)
 return
def s_default():
 os.system('clear')
 choice = raw_input("(**All user created menus will be erased**)\nAre you sure? (YES / NO) or Back\n >> ")
 if choice.lower() == 'back':
 show_settings()
 elif choice.lower() == 'yes':
 print 'all settings have been set to default'
 del user_menu_items[:] # removing all items from user menu
 show_settings()
 elif choice.lower() == 'no':
 show_settings()
 return
def e_create():
 go = True
 addeditem = []
 global user_menu_items
 while go: 
 badinput = False
 if badinput == True:
 print "That's not a selection. Please try again..."
 else:
 os.system('clear')
 if addeditem != '':
 z = 0
 for i in addeditem:
 print(addeditem[z])
 z += 1
 if not user_menu_items:
 print
 print "\n**Menu Items**"
 z = 0
 for i in user_menu_items:
 print(user_menu_items[z])
 z += 1
 choice = raw_input("\nCreate New Item? (YES / NO)\n >> ")
 if choice.lower() == 'yes':
 additem = raw_input("\n\nSpecify Name of New Menu Item: ")
 addeditem.append(add_userItem(additem))
 user_menu_items.append(additem)
 else:
 if choice.lower() == 'no':
 go = False
 else: 
 badinput = True
 s_edit()
 return
def e_modify():
 os.system('clear')
 print "Rename"
 print "Delete"
 print "Move Item"
 print "\nBack\n"
 choice = raw_input("Choose an action: ")
 return choice
def m_rename():
 os.system('clear')
 print "\nBack\n"
 choice = raw_input("Enter a new name: ")
 return choice
def m_delete():
 os.system('clear')
 print "\nBack\n"
 choice = raw_input("Select Menu Item to Delete: ")
 return choice
def m_move():
 os.system('clear')
 print "\nBack\n"
 choice = raw_input("Specify new location: ")
 return choice
def goback():
 os.system('clear')
 print "\nBack\n"
 decision('')
 return
def user_menu():
 z = 0
 for i in user_menu_items:
 print(user_menu_items[z])
 z += 1
 return
def main_menu():
 os.system('clear')
 user_menu()
 print "\nSettings"
 print "Quit"
 choice = raw_input(" >> ")
 decision(choice)
 return
def decision(decision):
 dec = decision.lower()
 if dec == '':
 menu_actions['main menu']()
 else: 
 try:
 menu_actions[dec]()
 except KeyError:
 print "invalid selection, please try again.\n"
 menu_actions['main menu']()
 return
menu_actions = {
 'main': main_menu,
 'settings': show_settings,
 'quit': quit,
 'edit': s_edit,
 'default': s_default,
 'create': e_create,
 'modify': e_modify,
 'rename': m_rename,
 'delete': m_delete,
 'move': m_move,
 'back' : goback
 }
main_menu()

About: As you can see, I have designed a menu creator based on user input, while still providing a fixed menu system for creating and modifying the user-created menus. My desire was to display one tier at a time, making menu items numerically selectable (except for "go back" and "quit"). Below is a pseudo code view of my desired menu tree.

I should also mention that I am fully aware of the fact that the user-created menu items will not have any particular functionality, but I figured I could use this program to create the menus and then code functionality later on -- if desired.

Desired Menu Tree:

1. Settings

   1. Edit Menu

      1. Create> # Specify Location of Menu Item.> # Specify Name of New Menu Item.
      2. Modify> # Select Menu Item to Modify.> # Pick an Action?
         1. Rename> # Enter a new name
         2. Delete> # Select Menu Item to Delete.
         3. Move Item> # Where?

      x. Go Back

   2. Default Settings (All user created menus will be erased)> #Are you sure? (YES / NO?)

x. Quit> #exit program

• Archit Jain: Can you fix the indentation so that your initial code and intent can be undetstood ? Your code doesn't runs with current indentation. Start fixing with line#63
• holaymolay: All fixed, sorry about that, when I copied the text over and then specified it as code, stackexchange didn't recognize all of my indentions. You should be good to go now.

Answer 1

Disclaimer : your code is not indented properly and I cannot run it. Also, it seems a bit convoluted to me so I haven't really tried to understand it. However, here are a few comments that might help you if you want to improve your code.

---

Keep it simple

def add_userItem(item):
 returnitem = "item " + item + " created..."
 return returnitem

could be

def add_userItem(item):
 return "item " + item + " created..."

---

goback could just call main_menu() instead of decision(''). This would make decision() much simpler as it shouldn't be its duty to try to handle special cases (see Separation of Concerns)

---

You don't need to have menu_actions at the top of your file.

---

return at the end of the function is not required if you don't plan to return any value.

---

 choice = raw_input("Choose an action: ")
 return choice

could be

 return raw_input("Choose an action: ")

---

---

For Loop

The way Python loops is designed is supposed to help you to write concise and expressive code : what you write should match pretty closely how you think about things : "I want to do this for each item in this container" instead of "I want to have this index and I start at 0 and I increment and I get the element at this index...".

 z = 0
 for i in addeditem:
 print(addeditem[z])
 z += 1

should be written :

 for i in addeditem:
 print(i)

How nice is this ?

Pretty much everytime you initialise a variable at 0 to use it as an index in a loop you are doing it wrong. If you really need to know what is the current index, enumerate is what you are looking for.

---

---

Don't repeat yourself

 for i in user_menu_items:
 print(i)

appears in your code twice. You should just call user_menu.

---

Multiple methods looks quite similar, it might be worth defining a more generic function and then just calling it everywhere

---

 if choice.lower() == 'back':
 show_settings()
 elif choice.lower() == 'yes':
 print 'all settings have been set to default'
 del user_menu_items[:] # removing all items from user menu
 show_settings()
 elif choice.lower() == 'no':
 show_settings()

calls lower() and show_settings in 3 different places. It might be easier to do something like :

 choice = raw_input("(**All user created menus will be erased**)\nAre you sure? (YES / NO) or Back\n >> ").lower()
 if choice == 'yes':
 print 'all settings have been set to default'
 del user_menu_items[:] # removing all items from user menu
 show_settings()
 elif choice in ['back','no']:
 show_settings()

---

If you ever change the label of menu (which most likely happened already - I assume that main menu is its old name), things will fail and you'll have to fix it in different places in decision.

What about doing :

def decision(decision):
 try:
 menu_actions[decision.lower()]()
 except KeyError:
 print "invalid selection, please try again.\n"
 main_menu()

---

Documentation

You should add comments at least to describe the program and the different main functions.

• holaymolay: This is excellent feedback, thank you Josay. I am new to programming and only recently began being more disciplined with using comments. I will go back and work on it cleaning things up a bit before submitting my edits. Thanks!