Python Classes Demo

This repo is a small, progressive demo of Python classes, inheritance, and simple business rules using a food-themed domain. It includes base classes, subclasses, and behavior rules to illustrate how state and logic can live on objects.

What’s Inside

• food.py
  • Base class: Food
  • Subclasses: Fruit, Meat, Beverage
• meal.py
  • Composition: Meal
• person.py
  • Base class: Person
  • Subclass: Vegetarian

Key Principles Illustrated

• Inheritance and method overriding (Fruit.eat, Meat.eat, Beverage.drink)
• Composition (Meal contains multiple Food items)
• State and validation inside methods (edibility, allergies, hand-washing)
• Polymorphism (different Food types can be handled uniformly)
• Simple domain rules (vegetarian restriction, diabetic fruit limit, alcohol age check)

Rules Modeled

• People must wash hands before eating/drinking.
• Fruit must be washed and ripe before it can be eaten.
• Meat must be cooked before it can be eaten.
• Vegetarian cannot eat Meat.
• Diabetics can only eat one fruit.
• Alcoholic beverages require age 21+.
• During a Meal, people only become full at the end of the meal.

Examples

Run any example with:

python example01.py

Example progression:

• example01.py — Minimal: 1 Person, 1 Food
• example02.py — Meat cooking requirement
• example03.py — Fruit washing/ripening + Meat
• example04.py — Allergies, Vegetarian, and diabetic fruit limit
• example05.py — Beverage with adult vs child
• example06.py — Allergy restriction example
• example07.py — Meal with beverages and age rules
• example.py — Full demo combining multiple features

Files

• food.py
• meal.py
• person.py
• example.py
• example01.py
• example02.py
• example03.py
• example04.py
• example05.py
• example06.py
• example07.py