33 — Todo: a growing project

Guide 31 saved a list of dicts with json_save; 23 moved code into modules. This guide grows both into a todo list project.

#Steps

1. Storage lives in a module, store.nme, exporting load() and save(todos):

   # store.nme — file storage for the todo list.
   
   import os
   use file latest
   
   def load():
       if os.path.exists("todos.json"):
           return json_load("todos.json")
       return []
   
   def save(todos):
       json_save("todos.json", todos)
   

   copyrun it →

2. The whole project. Save todo.nme next to store.nme:

   # todo.nme — a todo list that survives between runs.
   # Run: nme r todo
   
   from "store.nme" import load, save
   todos = load()
   
   while True:
       show ""
       show "Commands: add, done, list, quit"
       ask command, "? "
       if command == "add":
           ask text, "Todo? "
           todos.append({"text": text, "done": False})
           save(todos)
           show f"Added: {text}"
       elif command == "done":
           ask num, "Number? "
           i = int(num)
           if i >= 0 and i < len(todos):
               todos[i]["done"] = True
               save(todos)
               show f"Done: {todos[i]['text']}"
           else:
               show f"No todo number {i}"
       elif command == "list":
           show f"{len(todos)} todos"
           for i in range(len(todos)):
               if todos[i]["done"]:
                   show f"{i}: [x] {todos[i]['text']}"
               else:
                   show f"{i}: [ ] {todos[i]['text']}"
       elif command == "quit":
           show "Bye!"
           break
       else:
           show "Unknown command"
   

   copy

   add appends a dict and saves immediately; done marks a todo by number with an and range check.

3. Run it and feed the commands through a pipe:

   printf 'add\nbuy milk\ndone\n0\nlist\nquit\n' | nme r todo
   

   copy

   Commands: add, done, list, quit
   ? Todo? Added: buy milk
   
   Commands: add, done, list, quit
   ? Number? Done: buy milk
   
   Commands: add, done, list, quit
   ? 1 todos
   0: [x] buy milk
   
   Commands: add, done, list, quit
   ? Bye!
   

   copy

   The todo is saved to todos.json, so the next run loads it back. Korean writes the same menu with 물어봐 and 말해; the full pair is in the Korean guide.

#Try it yourself

Add a clear command that resets todos to [] and saves — one elif branch. Then make list count the open items.

#What you learned

• A project splits into a main program and a storage module with a clear interface.
• json_save persists a list of dicts; load() restores it on the next run.
• int(num) and the and range check keep a number command safe.