Python Expense Tracker Project: Step-by-Step Code & Tutorial

### Step 1: Project Setup Create a folder `expense_tracker` and a file `tracker.py`. Import `json` and `os` built-in modules at the top of the file.

### Step 2: Core Logic Implementation Implement functions to load and save data from JSON. ```python import json import os DATA_FILE = "data.json" def load_data() -> list: if not os.path.exists(DATA_FILE): return [] with open(DATA_FILE, "r") as f: return json.load(f) def save_data(expenses: list): with open(DATA_FILE, "w") as f: json.dump(expenses, f, indent=4) ```

### Step 3: UI & Interaction Implementation Create the console menu and report formatting logic. ```python def add_expense(expenses: list): amount = float(input("Enter amount: ")) category = input("Enter category (Food, Travel, Bills, Other): ") desc = input("Enter description: ") expenses.append({"amount": amount, "category": category, "desc": desc}) save_data(expenses) print("Expense added successfully!") ```

### Step 4: Error Handling & Edge Cases Ensure corrupted JSON files are caught gracefully and invalid numerical inputs don't crash the application.