Virtual Pet (Python OOP) — Multi-Pet with JSON (Codeboard)

OnlineGBD project: (Link)
Use the starter code provided in the OnlineGBD project. You will implement missing logic in pet.py and make small in Root/main.py as described below.

Learning Goals

• Build and use classes (attributes, methods)
• Manage program state with a game loop
• Persist data with JSON (save/load)
• Handle input validation and clean CLI UX

What You’ll Build

A text-based Virtual Pet game. Each pet has hunger, energy, and happiness that change over time. You can create multiple pets, switch the active pet, play with it, and save/load all pets to/from a JSON file.

Files in Codeboard

• pet.py — the Pet class (you implement most logic here)
• Root/main.py — menus, multi-pet management, JSON save/load scaffolding and game loop

Minimum Requirements (MVP)

1) Pet class (pet.py)

Implement and/or tune:

• Attributes (initialize in __init__):
  • name, hunger (0–100; higher = hungrier), energy (0–100), happiness (0–100), age_days, alive
• Actions (return a short message string; clamp values to 0–100):
  • feed(self)
  • play(self)
  • sleep(self)
  • pet(self) (affection)
• Time & life
  • tick(self) — called after every action; stats drift; age_days increments; call life checks
  • _life_checks(self) — set alive = False on your chosen lose conditions (e.g., hunger ≥ 100 or energy ≤ 0)
• Reporting
  • status(self) — return a readable multi-line string of the pet’s current state (ASCII only)
• JSON serialization
  • to_dict(self) and from_dict(cls, data) — convert between Pet instances and plain dicts

2) Multiple Pets (in Root/main.py)

Main menu must let the player:

• Create a new pet
• Select active pet
• List pets
• Play with active pet (action loop)
• Save all pets to one JSON file (e.g., pets.json)
• Load pets from that JSON file

3) Save/Load (JSON)

• Save all pets into a single JSON object {name: pet_dict, ...}
• Load from that file and reconstruct Pet objects using Pet.from_dict
• Handle missing/invalid files gracefully (don’t crash)

4) Game Loop & UX

• While the active pet is alive: show status → choose action → apply → tick()
• Validate input (no crashes on bad choices)
• End the pet’s loop if it dies (show an ASCII message)

Stretch Features (pick ≥ 2 for creativity points)

• Random events (found a toy, got sick, etc.)
• Simple ASCII moods (no Unicode)
• Items/inventory (treats, medicine)
• Aging/evolution milestones
• Per-pet save files in addition to the global save
• Basic unit tests (e.g., test_pet.py in the project)

How to Run on Codeboard

1. Open the project and click Run.
2. Follow on-screen menus to Create Pet, Select Active Pet, then Play with Active Pet.
3. Use Save All Pets to write pets.json in the project.
4. Use Load Pets to load them back later.

If you see encoding errors, you still have a Unicode symbol somewhere. Replace em dashes (—) with --, ellipsis (…) with ..., and remove emojis.

JSON Examples (students can copy/paste)

Write a dict to JSON (already used by the starter):

import json
data = {"answer": 42, "things": [1, 2, 3]}
with open("pets.json", "w") as f:
    json.dump(data, f, indent=2)

Read JSON back:

import json
with open("pets.json", "r") as f:
    loaded = json.load(f)
# loaded is now a dict

Save pets using to_dict():

data = {}
for name in pets:
    data[name] = pets[name].to_dict()
with open("pets.json", "w") as f:
    json.dump(data, f, indent=2)

Load pets using from_dict():

from pet import Pet
import json

with open("pets.json", "r") as f:
    raw = json.load(f)

pets = {}
for name in raw:
    pets[name] = Pet.from_dict(raw[name])

Example pets.json:

{
  "Fluffy": {
    "name": "Fluffy",
    "hunger": 25,
    "energy": 82,
    "happiness": 70,
    "age_days": 3,
    "alive": true
  },
  "Rex": {
    "name": "Rex",
    "hunger": 60,
    "energy": 41,
    "happiness": 55,
    "age_days": 7,
    "alive": true
  }
}

What to Edit (Quick Checklist)

In pet.py

• Tune starting values in __init__
• Implement stat changes in feed, play, sleep, pet (remember to clamp)
• Implement tick (drift stats + aging + _life_checks)
• Implement _life_checks (your lose rules)
• Keep all output ASCII in status() (no emojis, no “smart” punctuation)

In Root/main.py

• Keep save_all_pets / load_all_pets working with pets.json
• Make sure Select Active Pet and Play logic handles “no active pet” safely

Testing

In main at the bottom there is a call to test_pet_runner(). You can uncomment this, and comment out the call to main() to test the code. It should pass all tests.

Deliverables

• Your edited Codeboard project (starter files completed)
• A short README.txt describing:
  • Lose conditions you chose
  • How each action affects stats
  • Stretch features implemented
  • How to run, save, and load

Suggested Timeline

Grading Rubric (100 pts)

Extra credit (+ up to 10): outstanding polish, novel mechanics, or strong tests.

Troubleshooting (OnlineGBD)

• JSON errors: ensure you’re writing a dict, not a string; verify file name pets.json
• Crash on bad input: wrap menus with a loop that re-prompts until a valid choice