Personal Finance Tracker

Advanced Project

Track expenses and balance using OOP, JSON, datetime, and error handling.

Project Overview

Goal: Track income, expenses, and generate reports.

Concepts: File I/O, datetime, JSON, formatting, error handling.

Key Features:

• Add income and expenses
• Categorize transactions
• Generate monthly reports
• Calculate savings rate
• Budget warnings
• Data visualization (optional)

Technologies & Concepts:

OOP (Classes)JSONDatetimeFile I/OException Handling

Starter Code

💡 This full interactive version uses input() which requires a local Python environment.Jump to the Browser Demo below to see a simplified version running in your browser.

import json
import datetime
from pathlib import Path

class FinanceTracker:
    def __init__(self, filename="finance.json"):
        self.filename = filename
        self.data = self.load_data()
    
    def load_data(self):
        """Load existing data or create new structure"""
        try:
            with open(self.filename) as f:
                return json.load(f)
        except FileNotFoundError:
            return {"transactions": [], "balance": 0}
    
    def save_data(self):
        """Save data to JSON file"""
        with open(self.filename, "w") as f:
            json.dump(self.data, f, indent=2)
    
    def add_transaction(self, amount, description, category="General"):
        """Add income (positive) or expense (negative)"""
        transaction = {
            "amount": amount,
            "description": description,
            "category": category,
            "date": datetime.date.today().isoformat()
        }
        self.data["transactions"].append(transaction)
        self.data["balance"] += amount
        self.save_data()
        
        emoji = "💰" if amount > 0 else "💸"
        print(f"{emoji} Added: {description} ({amount:,.2f})")
    
    def show_balance(self):
        """Display current balance"""
        balance = self.data["balance"]
        color = "green" if balance >= 0 else "red"
        print(f"💵 Current Balance: {balance:,.2f}")
    
    def show_transactions(self, limit=10):
        """Show recent transactions"""
        transactions = self.data["transactions"][-limit:]
        print(f"📜 Recent Transactions (Last {limit}):")
        for t in transactions:
            amount = t["amount"]
            sign = "+" if amount > 0 else ""
            print(f"  {t['date']} | {t['description']:20} | {sign}{amount:,.2f} | {t['category']}")
    
    def monthly_report(self, month=None):
        """Generate report for specific month"""
        if month is None:
            month = datetime.date.today().strftime("%Y-%m")
        
        monthly_txns = [t for t in self.data["transactions"] 
                       if t["date"].startswith(month)]
        
        income = sum(t["amount"] for t in monthly_txns if t["amount"] > 0)
        expenses = sum(t["amount"] for t in monthly_txns if t["amount"] < 0)
        
        print(f"📊 Report for {month}")
        print(f"   Income: {income:,.2f}")
        print(f"   Expenses: {abs(expenses):,.2f}")
        print(f"   Net: {income + expenses:,.2f}")

# Example usage
tracker = FinanceTracker()
tracker.add_transaction(1000, "Salary", "Income")
tracker.add_transaction(-50, "Groceries", "Food")
tracker.add_transaction(-30, "Netflix", "Entertainment")
tracker.add_transaction(200, "Freelance work", "Income")
tracker.show_balance()
tracker.show_transactions()
tracker.monthly_report()

To run this locally: Save as finance_tracker.py and run python finance_tracker.py

Browser Demo (Simplified Version)

This version demonstrates the core functionality without requiring user input. Click "Run" to see it in action!

Finance Tracker Demo

Try it Yourself »

Python

from datetime import datetime

class FinanceTracker:
    def __init__(self):
        self.transactions = []
        self.balance = 0
    
    def add_transaction(self, amount, description, category="General"):
        """Add income (positive) or expense (negative)"""
        transaction = {
            "amount": amount,
            "description": description,
            "category": category,
            "date": datetime.now().strftime("%Y-%m-%d")
        }
        self.transactions.append(trans
...

Enhancement Ideas 🚀

1. Budget System

Set monthly budgets for categories and get warnings when approaching limits.

2. Data Visualization

Use matplotlib to create charts showing spending by category over time.

3. Recurring Transactions

Add support for recurring monthly expenses (rent, subscriptions).

4. Multi-Currency Support

Track transactions in different currencies with automatic conversion.

5. Export to CSV/Excel

Allow exporting transaction history for analysis in spreadsheet software.

Next Steps

Test the tracker with sample transactions
Add category management (add/edit/delete categories)
Implement search and filter functionality
Create yearly comparison reports
Add data visualization with charts
Build a budget tracking system
Consider adding user authentication for privacy

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