Object Oriented Programming in Python

Study Notes

Classes & Objects

A class serves as a blueprint for creating objects and defines a new data type.
Objects consist of data (stored in instance variables) and behaviors (defined by methods in the class).
The structure of a class combines variables, functions, and statements, representing data and behaviors.

Object Oriented Programming (OOP)

OOP views programs as collections of objects that have attributes (what they know) and methods (what they can do).
Objects can communicate and interact to perform tasks, leveraging their attributes and methods.

Python as an OOP Language

Python implements OOP by utilizing classes for all data types, allowing creation of objects such as lists and strings.
Lists and strings are examples of collections; methods on these objects allow manipulation, like sorting a list or changing string case.

Python Objects

In Python, even classes themselves are considered objects, emphasizing the universal application of object-oriented principles.

Characteristics of OOP

Data is stored in objects, which are instances of classes; classes act as blueprints for object creation.
OOP features include:
- Encapsulation: Hides implementation details and binds data with functions, improving clarity and ease of modification (e.g., a string stored as data has associated methods).
- Polymorphism: Enables the same method call to behave differently based on the object type.
- Inheritance: Allows new objects to inherit characteristics from existing ones while modifying or extending them.
- Modularity: Enables standalone objects suitable for reuse, exemplified by modules like math or random.

Naming Conventions in OOP

Class names start with a capital letter using PascalCase (e.g., StudentRecord).
Method names align with function naming and typically use verb phrases, such as get_value.
Constant names are written in uppercase.
Variable names begin with a lowercase letter and often use underscores (e.g., my_name).

The 'type' Function

The type() function determines the type of an object, revealing its class and associated properties.
Example outputs indicate the specific data structure type, such as list or dictionary.

Class & Instance

A class is a template used to create instances (objects), defining their attributes and operations.
Each instance holds distinct data but adheres to the class structure.

Built-In Classes in Python

Python's built-in data structures (e.g., list, str, dict, and tuple) are defined as classes.
Creating an instance of these structures results in objects with specific types and associated methods for data manipulation.

Class Definition

Defined using the keyword class, followed by a class name in PascalCase and parentheses.
An empty class can be initiated with the pass statement, indicating future intent to add functionality.

The 'dir' Function

The dir() function lists all attributes and methods of a class, providing insight into object capabilities.
Utilized with a class name, it shows built-in attributes that pertain to the class structure and behavior.

Description

This quiz covers the fundamentals of Object Oriented Programming (OOP) in Python, focusing on classes, objects, and their interactions. Understand how to create and manipulate objects and the significance of methods and attributes within the OOP paradigm.