Chapter 10 - OOP in Python Flashcards

Questions and Answers

What is an object?

An object is a software entity that contains both data and procedures.

What is encapsulation?

Encapsulation is the combining of data and code into a single object.

Why is an object's internal data usually hidden from outside code?

To protect the data from accidental corruption and because the outside code does not need to know the internal structure of the data.

What are public methods?

Public methods can be accessed by entities outside the object. Signup and view all the answers

What are private methods?

Private methods cannot be accessed by entities outside the object. Signup and view all the answers

In the metaphor of a blueprint and houses, what does the blueprint represent?

The blueprint represents a class. Signup and view all the answers

In the cookie cutter metaphor for classes and objects, what do the objects represent?

Objects are the cookies. Signup and view all the answers

What is the purpose of the init method?

Its purpose is to initialize an object's data attributes. Signup and view all the answers

What is the purpose of the self parameter in a method?

The self parameter allows a method to reference the specific object's data attributes it operates on. Signup and view all the answers

How do you hide an attribute from code outside the class?

By starting the attribute's name with two underscores. Signup and view all the answers

What is the purpose of the str method?

It returns a string representation of the object. Signup and view all the answers

How do you call the str method?

By passing the object to the built-in str method. Signup and view all the answers

What is an instance attribute?

An attribute that belongs to a specific instance of a class. Signup and view all the answers

What is an accessor method?

A method that returns a value from a class's attribute but does not change it. Signup and view all the answers

What is a mutator method?

A method that stores a value in a data attribute or changes the value of a data attribute in some way. Signup and view all the answers

What appears in the three sections of a typical UML diagram for a class?

The top section holds the class name, the middle section holds a list of fields, and the bottom section holds a list of methods. Signup and view all the answers

What is a problem domain?

A written description of the real-world objects, parties, and major events related to the problem. Signup and view all the answers

Who should write a description of the problem domain when designing an object-oriented application?

If you understand the nature of the problem well, you can write it yourself; otherwise, you should have an expert do it. Signup and view all the answers

How do you identify the potential classes in a problem domain description?

Identify nouns, pronouns, and pronoun phrases, then refine the list to eliminate duplicates and unrelated items. Signup and view all the answers

What are a class's responsibilities?

The things the class is responsible for knowing and the actions it must perform. Signup and view all the answers

What two questions should you ask to determine a class's responsibilities?

<ol> <li>What must the class know? 2) What must the class do?</li> </ol> Signup and view all the answers

Study Notes

Key Concepts in Object-Oriented Programming

An object represents a software entity that encapsulates both data and procedures.
Encapsulation combines data and code into a coherent single unit or object.
An object's internal data is hidden from outside code to protect it from accidental corruption and to reduce dependencies on the object's internal structure.

Accessibility of Methods

Public methods can be accessed by external entities, allowing interaction with the object's data.
Private methods are restricted to internal access, intended solely for use within the object itself.

Metaphorical Representations

A blueprint serves as a metaphor for a class, outlining the design for creating objects.
Objects are likened to cookies, which are the result of the cookie cutter (the class).

Object Initialization and Attributes

The init method initializes an object's data attributes upon object creation.
The self parameter in methods allows the function to know which object's attributes to manipulate, linking methods to their respective instances.
Attributes can be hidden by prefixing their names with double underscores.

String Representation and Attribute Types

The str method generates a string representation of the object for easy readability.
An instance attribute is specific to an instance, differentiating it from class attributes.

Methods in Classes

An accessor method retrieves values from attributes without modifying them.
A mutator method updates or changes the values of an attribute, performing the necessary state changes.

UML and Design

A typical UML diagram for a class has three sections: class name, fields (attributes), and methods.
A problem domain refers to a written depiction of real-world elements involved in the problem being solved.

Problem Domain Analysis

When writing a problem domain description, a person with thorough understanding or an expert in the field should be consulted to ensure clarity.
Identify potential classes by pinpointing nouns and phrases in the domain description, then refining that list to focus on relevant classes.

Class Responsibilities

A class's responsibilities encompass what the class needs to know and the actions it must perform.
To determine a class's responsibilities, ask:
- What must the class know?
- What must the class do?

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge of object-oriented programming concepts with these flashcards from Chapter 10 of 'Starting Out with Python, 3e'. Cover key terms such as objects and encapsulation, and explore their significance in software development.