Question

Make a new class called Thing2 and assign the value 'abc' to a class attribute called letters. Print letters.

Short answer

Create `class Thing2` and assign `letters = 'abc'`, then print with `print(Thing2.letters)`.

Step-by-step solution

Define the Class

Create a new class named `Thing2` by using the `class` keyword followed by `Thing2`. This sets up the class structure.

Define a Class Attribute

Inside the class `Thing2`, define a class attribute `letters` and assign it the value `'abc'`. This is done inside the class block, directly under the class definition.

Print the Class Attribute

Outside of the class definition, use the class name `Thing2` and dot notation to access the `letters` attribute and then use the `print()` function to display its value. This will print the value `'abc'` to the console.

Key concepts

Class Definition

To create a class in object-oriented programming, you begin with a class definition. This is essentially a blueprint for creating objects. You start by using the keyword `class`, followed by the name of the class you want to create. For instance, in our problem, we defined a class named `Thing2`. A class definition does not need to contain any objects or variables yet—it simply sets up a space where these items can be organized. However, it’s important to remember that this setup is the foundation for your objects. You can think of it as designing a house before it's built. It’s worth noting that class names typically start with a capital letter by convention. This helps distinguish them from functions and variables, which are usually written in lowercase.

Class Attribute

A class attribute is a variable that's shared across all instances of a class. Think of it like a shared resource for everything created from this class blueprint. In our example, we assigned the value `'abc'` to a class attribute called `letters` in the `Thing2` class. Defining a class attribute is quite easy. You simply write it inside the class block, directly under the class definition. This means that all objects of `Thing2` will have access to the `letters` attribute and its value. Some key points about class attributes:

• They are shared across all instances of the class.
• Changing the attribute in one instance affects it in all instances unless it’s overridden.
• It's useful for constants or default values that need to be accessible for every object of the class.

In essence, class attributes provide a mechanism for organizing data that is consistent across all objects created from this class.

Dot Notation

Dot notation is the way programmers access an object's attributes and methods in Python. It’s a simple but powerful tool. After defining your class and its attributes, you can use dot notation to call them outside the class. In the provided exercise, we accessed the `letters` attribute of the `Thing2` class using dot notation. Here's how it looks: - Write the class name or the instance name - Add a dot (`.`) - Follow it with the attribute name For example, to print the class attribute `letters`, you write `Thing2.letters`. What happens here is that the Python interpreter looks inside the `Thing2` class for the `letters` attribute and retrieves its value. This dot notation approach is reliable and aligns well with the logical structure of object-oriented programming, making it intuitive for organizing and accessing class data.