Inheriting properties from built-in classes

Python gives you the ability to create a class that inherits properties from any Python built-in class in order to get a new class that can enrich the parent's attributes or methods. As a result, your newly-created class has the advantage of all of the well-known functionalities inherited from its parent or even parents and you can still access those attributes and methods.

Later, you can override the methods by delivering your own modifications for the selected methods.

In the following example, we’ll create an implementation of our own list class, which will only accept elements of the integer type. But, wait – why might you need such an object?

Imagine that you need to collect the serial numbers of sold tickets. Sound reasonable enough?

Your new class will be based on the Python list implementation and will also validate the type of elements that are about to be placed onto it.

Such a list can be used in an application that requires the list elements to be of a specific type (integers in the ticketing example), and control over the types of elements is given to the mechanisms of the new class.

As a result, when solving a domain problem, we focus on the problem and not on type control.