MenuMatrix CLI Application

Overview

MenuMatrix is a Python-based Command Line Interface (CLI) application designed to manage a restaurant’s menu system. Built using SQLAlchemy for ORM and Alembic for migrations, it offers a smooth, terminal-driven experience to add menu items, place orders, and interact with stored data seamlessly

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Learning Goals

• Build a modular CLI application using Python
• Implement SQLAlchemy ORM for persistent data handling
• Apply Alembic for database schema migrations
• Follow clean coding, separation of concerns, and best practices in project organization

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Project Structure

.
├── alembic.ini          # Alembic configuration file
├── app.db               # SQLite database file (can be replaced with any DB)
├── CONTRIBUTING.md      # Guidelines for contributing to the project
├── LICENSE.md           # Project license information
├── lib
│   ├── cli.py           # Entry point for the CLI app
│   ├── db.py            # Database engine and session setup
│   ├── helpers.py       # Helper functions for CLI commands
│   ├── debug.py         # Script to manually test models or sessions
│   ├── models
│   │   ├── __init__.py  # Initializes DB connection constants
│   │   └── models.py    # SQLAlchemy models (MenuItem, Order, etc.)
│   └── db
│       ├── session.py   # SQLAlchemy session instance
│       └── app.db       # SQLite database file
├── migrations           # Folder containing Alembic migration scripts
│   ├── versions         # Individual migration scripts
│   └── ...
├── Pipfile              # Defines Python dependencies
├── Pipfile.lock         # Locked Python dependency versions
├── README.md            # Project documentation

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How to Run the App

1. Clone the Repository

git clone git@github.com:DevBrianKE/menumatrix.git
cd menumatrix

2.Install dependencies:

pipenv install
pipenv shell

3. Run the database migrations:

alembic upgrade head

4. Start the CLI:

python -m lib.cli

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Features

• View menu items

• Add new menu items

• Place new orders

• View existing orders

• Delete menu items or orders

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Tech Stack & Tools

• Python 3.8+ – Core programming language
• SQLAlchemy – ORM for database interactions
• Alembic – Database migration tool
• Tabulate – For displaying pretty CLI tables
• SQLite – Lightweight, file-based relational database
• Modular Structure – Scalable and organized codebase

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Key Files and Their Roles

lib/cli.py

Main program loop for the CLI:

def main():
    while True:
        print_menu()
        choice = input("Enter your choice (1-6): ").strip()
        if choice == "1":
            # Add a Menu Item
            ...
        elif choice == "2":
            # List Menu Items
            ...
        elif choice == "3":
            # Create New Order
            ...
        elif choice == "4":
            # Add Item to Order
            ...
        elif choice == "5":
            # View Order Items
            ...
        elif choice == "6":
            exit_program()
        else:
            print("Invalid choice, please enter a number between 1 and 6.")

lib/helpers.py

Handles the logic:

def view_menu():
    items = session.query(MenuItem).all()
    for item in items:
        print(item)

• add_menu_item(name, price, description=None): Adds a new menu item to the database.
• list_menu_items(): Retrieves all menu items.
• create_order(): Creates a new order.
• add_item_to_order(order_id, menu_item_id, quantity=1): Adds menu items to an existing order.
• get_order_details(order_id): Fetches detailed information about an order.
• exit_program(): Gracefully exits the application.

lib/models/models.py

SQLAlchemy models defining relationships:

class MenuItem(Base):
    __tablename__ = 'menu_items'
    id = Column(Integer, primary_key=True)
    name = Column(String(100), nullable=False)
    price = Column(Float, nullable=False)
    description = Column(String(250), nullable=True)

class Order(Base):
    __tablename__ = 'orders'
    id = Column(Integer, primary_key=True)
    timestamp = Column(DateTime, default=datetime.utcnow)
    status = Column(String(50), default='pending')
    order_items = relationship('OrderItem', back_populates='order')

class OrderItem(Base):
    __tablename__ = 'order_items'
    id = Column(Integer, primary_key=True)
    order_id = Column(Integer, ForeignKey('orders.id'))
    menu_item_id = Column(Integer, ForeignKey('menu_items.id'))
    quantity = Column(Integer, default=1)
    order = relationship('Order', back_populates='order_items')
    menu_item = relationship('MenuItem')

lib/db/session.py

Handles session management:

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, scoped_session

DATABASE_URL = "sqlite:///lib/db/app.db"

engine = create_engine(DATABASE_URL, echo=False, future=True)

SessionLocal = scoped_session(
    sessionmaker(autocommit=False, autoflush=False, bind=engine)
)

def get_session():
    return SessionLocal()

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Database Migrations with Alembic

Running Migrations

1. Modify Models

Update your models in lib/models/models.py as needed.

2. Generate Migration Script

alembic revision --autogenerate -m "Your migration message"

3. Apply the Migration to Your Database

Upgrade your database to reflect the new schema:

alembic upgrade head

3. Apply Migration

alembic upgrade head

Configuration Notes

• Ensure Alembic can detect your models by importing them in your env.py or migration environment:

-In your alembic.ini file, set the database URL:

sqlalchemy.url = sqlite:///lib/db/app.db 

Author

Kipchumba Brian
Full-Stack Developer | Software Engineer | Data Enthusiast

• Portfolio: https://devbrianke.github.io/My-Portfolio/
• LinkedIn: https://www.linkedin.com/in/kipchumba-brian-3a3a41150/
• GitHub: https://github.com/DevBrianKE
• Blog: MenuMatrix Python CLI Menu Management