A Preface to Data Structures in Python

Before we get started, we should address a few important terms that will be used in this lesson.

Class, Objects, and Methods

A class is a blueprint for creating objects. An object is an instance of a class. Along with this, a method is a function that is defined within a class. Along with this, we also have attributes within classes. These are just variables that are defined within a class. You use methods a lot within python and especially when working with the built-in data structures.

Example:

[1, 2, 3].append(4)

This is a really helpful bit of code. The append keyword is a method within the list class, and acts as a way to add an element to the end of the list.

We will discuss this further in classes.

Mutable and Immutable Objects

In Python, there are two main types of objects: mutable and immutable. Mutable objects can be modified after creation, while immutable objects cannot. Some examples of immutable objects include strings, integers, and tuples. Whenever you modify an immutable object, a new object is created (new value). Mutable objects include lists and dictionaries, which can be changed in place without creating a new object.