Objects and Classes

 we're going to discuss objects and classes. In Python, various data types such as integers, floats, strings, lists, dictionaries, and booleans are all objects. Each object possesses:

1. A type.
2. An internal representation.
3. A set of functions known as methods to interact with the data.

An object represents an instance of a particular type. For instance, we can have multiple objects of type one, each being an instance of type one. Similarly, we can have several objects of type two, each being an instance of type two.

Now, let's delve into less abstract examples. Whenever we create an integer, we're essentially creating an instance of the integer type, or an integer object. Likewise, when we create a list, we're generating an instance of the list type, or a list object.

Determining the type of an object can be achieved using the type command. For instance, we can identify an object of type list, integer, string, or dictionary.

A class or type's methods are functions that every instance of that class or type provides. These methods enable interaction with the object's data. For instance, sorting is a method that modifies the data within a list object.

Next, we'll explore how to construct our own classes. In Python, you can create your own types or classes. This involves defining data attributes and methods for the class. Then, you can create instances or objects of that class.

Let's create two classes: a circle and a rectangle. To define a circle, we require a radius and a color attribute. Similarly, a rectangle necessitates attributes such as color, height, and width.

To create the circle class, you need to specify the class definition with the class name and inherit from the object class. Similarly, the rectangle class is defined in a similar manner, but with different attributes.

Classes serve as blueprints, and we set the attributes to create objects. We can then create objects that are instances of a specific class, initializing their attributes accordingly.

For example, we can create a circle object with a radius of four and a color of red. Similarly, we can instantiate a rectangle object with a height of two, a width of two, and a color of blue.

To construct these classes in Python, we define the class and initialize each instance with data attributes using the class constructor. The __init__ function acts as a constructor and is responsible for initializing the attributes. The self parameter refers to the newly created instance of the class.

Methods in a class are functions that interact with and modify the data attributes of the object. For instance, if we want to change the size of a circle, we can define a method called add_radius. This method takes the self parameter along with other parameters, such as the amount to add to the radius.

In the labs, you'll find a more detailed implementation of classes and methods, along with examples of creating objects and accessing their attributes.

In summary, objects in Python are instances of classes, and classes serve as blueprints for creating objects. We can define data attributes and methods within classes to define their behavior and interactions. Use the dir function to obtain a list of data attributes and methods associated with a class.