Bank Account Management System

(Tkinter + SQLite + Argon2id)

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A desktop Bank Account Management System built with Python and Tkinter. It supports admin and customer workflows, stores data in SQLite, and secures credentials with Argon2id hashing. The UI is intentionally simple and fast, while the backend focuses on correctness and safety.

If you read only this README, you should understand how the system works, how the data is stored, and how to operate or extend it.

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What This App Does

Admin features

• Create and delete admin accounts
• Create and delete customer accounts
• View customer account summaries

Customer features

• Secure login with PIN
• Deposit and withdraw funds (with limits)
• Change PIN
• View balance and account summary
• Close account

Security highlights

• Admin passwords and customer PINs are hashed with Argon2id
• SQLite storage (no plaintext credentials)
• Input validation at the service layer
• Transaction updates are atomic

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Architecture Overview

The project is split into clear layers:

• UI layer: bank_app/ui.py
  • Tkinter windows and user interactions
• Service layer: bank_app/services.py
  • Business rules, validation, and security
• Storage layer: bank_app/storage.py
  • SQLite schema and persistence
• Security: bank_app/security.py
  • Argon2id hashing and verification

This separation makes the code easier to test, reason about, and change safely.

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Data Model (SQLite)

The app stores data in data/bank.db with three tables:

admins

• username (unique)
• password_hash
• created_at

customers

• account_number (primary key)
• pin_hash
• balance (integer)
• created_at
• name
• account_type (Savings or Current)
• date_of_birth (DD/MM/YYYY)
• mobile
• gender
• nationality
• kyc_document

transactions

• account_number
• amount
• tx_type (deposit or withdraw)
• balance_after
• created_at

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Requirements

• Python 3.10+ (3.11 recommended)
• Tkinter (bundled with most Python installs on Windows/macOS)

Install runtime dependencies:

python -m venv .venv
.\.venv\Scripts\Activate.ps1

pip install -r requirements.txt

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Run the App

From the repo root:

python mainProject.py

You can also run:

python -m bank_app

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First-Time Admin Setup

If no admin exists, the Admin Login screen shows a Create First Admin button.

You can also bootstrap via environment variables (optional):

• BANKAPP_BOOTSTRAP_ADMIN_ID
• BANKAPP_BOOTSTRAP_ADMIN_PASSWORD

Example (PowerShell):

$env:BANKAPP_BOOTSTRAP_ADMIN_ID="admin"
$env:BANKAPP_BOOTSTRAP_ADMIN_PASSWORD="admin@123"
python mainProject.py

After the first admin is created, normal admin login is enabled.

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Usage Walkthrough

Admin

1. Open the app and choose Employee
2. Log in as admin
3. Use the menu to:
   • Create admins
   • Create customer accounts
   • View customer summaries
   • Close accounts

Customer

1. Open the app and choose Customer
2. Log in with account number + PIN
3. Use the menu to:
   • Deposit and withdraw money
   • Change PIN
   • Check balance
   • Close account

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Business Rules

• PIN must be exactly 4 digits
• Passwords must be at least 6 characters
• Minimum balance: 10000
• Max deposit/withdraw per transaction: 25000
• Date format: DD/MM/YYYY

These rules are enforced in bank_app/services.py and bank_app/validation.py.

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Tests

Install dev dependencies:

pip install -r requirements-dev.txt

Run the test suite:

pytest -q

Tests cover:

• Argon2id hashing and verification
• Validation rules (dates, mobile numbers)
• Core service workflows (admin/customer, deposit/withdraw)

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CI (GitHub Actions)

A workflow is included at .github/workflows/python-ci.yml to run tests on pushes and pull requests.

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Legacy Data Migration (Optional)

Older versions stored data in flat text files under database/. Those files are now deprecated and not used by the app.

If you need to import legacy data into SQLite:

python scripts/migrate_legacy.py

The script reads:

• database/Admin/adminDatabase.txt
• database/Customer/customerDatabase.txt

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Project Structure

bank_app/
  config.py
  errors.py
  security.py
  services.py
  storage.py
  ui.py
scripts/
  migrate_legacy.py
tests/
  test_security.py
  test_services.py
  test_validation.py
images/
mainProject.py
README.md

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Notes for Contributors

• Keep UI code in bank_app/ui.py and business logic in bank_app/services.py.
• Always validate inputs in the service layer.
• Avoid storing secrets in plaintext.
• If you add new features, add at least one test.

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Troubleshooting

App opens but icons are missing

• Make sure you run the app from the repo root so images/ is discoverable.

Tkinter is missing

• On Linux, install python3-tk via your package manager.

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