Topic 8. Classes and objects: attributes, methods, constructors, properties, and encapsulation

Goal: learn to design classes with invariants, initializers, properties, and different kinds of methods; distinguish class state from instance state, and model object relationships with UML.

Lecture contents

1. Classes, initialization, and attributes — Objects and classes · Class definition and initialization · Class and instance attributes
2. Encapsulation and properties — Encapsulation and the public interface · Properties: reading, writing, and deleting
3. Class methods and string representation — Class methods and static methods · String representation and object relationships
4. Identity and class design — Identity, equality, and the lifecycle · Design and working in PyCharm

Practice and review

• Practice — 3 worked examples with complete code
• Tasks — 30 variants, each with tasks at three difficulty levels
• Summary — conclusions, self-check questions, and useful links