💸 Personal Expense Tracker

A terminal-based personal finance tool built with Python. Track your daily expenses, categorize them, analyze spending patterns, and visualize your habits through charts — all from the command line, with each user's data stored separately.

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Features

• Multi-user support — Each user gets a unique ID and their own private data file
• Add & delete expenses — Log expenses with amount, category, date, and description
• Category filtering — View expenses under any specific category instantly
• Summary & stats — See total spending and breakdowns by category and month
• Charts & visualizations — Bar chart, pie chart, and monthly trend line using Matplotlib
• Persistent storage — All data is saved as CSV files, no database needed
• Re-login support — Switch between users within the same session

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Project Structure

expense-tracker/
│
├── main.py          # Entry point — handles UI, menus, and user flow
├── tracker.py       # ExpenseTracker class — core logic, file I/O, and pandas analysis
├── expense.py       # Expense data model with serialization helpers
├── charts.py        # Matplotlib chart functions (bar, pie, monthly trend)
│
├── data/            # Auto-created folder — stores per-user CSV files
│   └── USR1234.csv  # Example: one CSV per user ID
│
└── users.json       # Stores user ID → name mappings

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Tech Stack

Tool	Purpose
Python 3	Core language
Pandas	Data analysis and CSV handling
Matplotlib	Chart visualizations
JSON	User registry storage
CSV	Per-user expense storage

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How It Works

When you launch the app, you either register as a new user or log in with your existing User ID. New users get a generated ID like SUJ7823 — save it for future logins.

Once logged in, a menu lets you:

1. Add an expense (amount → category → description)
2. View all recorded expenses with a running total
3. Filter expenses by category
4. Delete any expense by its number
5. View a full summary with category and monthly breakdowns
6. View charts (bar, pie, or trend line)
7. Exit or switch to another user account

All data is automatically saved to data/<userID>.csv after every add or delete.

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Expense Categories

Food | Transport | Shopping | Entertainment | Health | Bills | Other

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Example Session

========================================
     PERSONAL EXPENSE TRACKER
========================================
1. I'm a new user
2. I'm an existing user
========================================
Select (1 or 2): 1

Enter your name: Sujit

Welcome, Sujit!
Your User ID is: SUJ4821
Please save this ID to log in next time.

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     PERSONAL EXPENSE TRACKER
========================================
1. Add Expense
2. View All Expenses
...

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Charts

Chart	Description
Bar Chart	Total spending per category
Pie Chart	Percentage distribution of expenses
Monthly Trend	Line graph showing spending over months

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