43 — Project: a habit tracker

Guide 33 saved a todo list of dicts; guide 23 split a project across files. A habit tracker is one dict — each habit's days in a row — saved to JSON.

#Steps

1. Storage lives in a module, store.nme, exporting load() and save(habits). A habit is a {name: days} dict entry; load() returns {} when no file exists yet:

   # store.nme — file storage for the habit tracker.
   import os
   use file latest
   def load():
       if os.path.exists("habits.json"):
           return json_load("habits.json")
       return {}
   
   def save(habits):
       json_save("habits.json", habits)
   

   copyrun it →

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

   # habit.nme — a habit tracker that survives between runs.
   # Run: nme r habit
   
   from "store.nme" import load, save
   habits = load()
   
   while True:
       show ""
       show "Commands: add, check, streak, list, quit"
       ask command, "? "
       if command == "add":
           ask name, "Habit? "
           habits[name] = 0
           save(habits)
           show f"Added: {name}"
       elif command == "check":
           ask name, "Habit? "
           if name in habits:
               habits[name] = habits[name] + 1
               save(habits)
               show f"Checked: {name} ({habits[name]} in a row)"
           else:
               show f"No habit named {name}"
       elif command == "streak":
           ask name, "Habit? "
           show f"{name}: {habits.get(name, 0)} days in a row"
       elif command == "list":
           show f"{len(habits)} habits"
           for name in habits:
               show f"{name}: {habits[name]}"
       elif command == "quit":
           show "Bye!"
           break
   

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   add starts a habit at 0; check adds 1 and saves; streak reads it back; list visits every pair.

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

   printf 'add\nwater\ncheck\nwater\ncheck\nwater\nstreak\nwater\nlist\nquit\n' | nme r habit
   

   copy

   
   Commands: add, check, streak, list, quit
   ? Habit? Added: water
   
   Commands: add, check, streak, list, quit
   ? Habit? Checked: water (1 in a row)
   
   Commands: add, check, streak, list, quit
   ? Habit? Checked: water (2 in a row)
   
   Commands: add, check, streak, list, quit
   ? Habit? water: 2 days in a row
   
   Commands: add, check, streak, list, quit
   ? 1 habits
   water: 2
   
   Commands: add, check, streak, list, quit
   ? Bye!
   

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   The habit started at 0 and grew to 2 — habits.json holds {"water": 2}. Korean writes the same menu with 물어봐 and 말해 — full pair in 43-habit.ko.md.

#Try it yourself

Add a reset command that sets a habit back to 0 — one elif branch and a save.

#What you learned

• A habit is a dict of {name: days}; habits[name] = habits[name] + 1 grows a streak.
• A module file owns load() and save(), and the main program imports them.
• json_save persists the whole dict after every change.
• A while True menu with add/check/streak/list/quit and break drives the tracker.