Part of what classes are used for in Python is to represent data. It is by using the __init__ function that we can accept data into an object as it is created, and assign those data values to the object using the self keyword. You might notice that sometimes this code setup has a lot of boilerplate to it. In other words, you have to write the same structure of code to simply store simple values on an object.…
Magic Methods in Python are a collection of methods that are automatically associated with every class definition in the language. If you create your own classes, you can override one or more standard magic methods to customize their behavior. There are many magic methods in Python, and we include a table of them at the end of this tutorial. For now, we want to take a look at some of the more commonly used magic methods which can be useful in day to day programming.…
Inheritance in Python is nice since it facilitates a great deal of code reuse. We put common data and behavior into a Base class and then implement any extra data and behavior needed in derived classes. Therefore when using inheritance, you are making use of an “is a” relationship. For example, a Car is a Vehicle. Another approach to code reuse when using the object-oriented style of programming in Python is Composition.…
By using a combination of multiple inheritance and abstract classes, you can use a design pattern in Python called an Interface. Interfaces are a common technique in object-oriented programming and programming languages like C# and Java implement this feature natively. Interfaces aren’t actually part of the Python language itself, but you can still use this type of design pattern with Python. In interface is a promise, or contract, that forces a given class to implement a given behavior.…
Python has the ability to make use of multiple inheritance, which allows a subclass to inherit functionality from multiple parent classes. Often times, multiple inheritances can be quite tricky, and some programming languages like Java strictly prohibit it. There are times when multiple inheritances can have its uses. It can be used to create objects that have two distinct sets of behaviors. Python makes use of something called the Method Resolution Order, or MRO, to determine how to inherit from more than one Superclass.…
Abstract base classes are special types of classes in Python. They allow a programmer to define a base class as a template for other classes to inherit from. The difference between abstract base classes and normal classes in Python is that with abstract base classes you don’t want consumers of your base class to be able to create instances of the base class itself. The abstract base class servers only as a blueprint.…
A key concept of object-oriented programming is that of inheritance. In this tutorial, we’re going to see how basic inheritance works in Python. Inheritance defines a way for a given class to inherit attributes and methods (variables and functions) from one or more base classes. This technique gives programmers the ability to centralize common functionality and data in a single place instead of having it spread out and duplicated across multiple classes.…
When writing a program in Python, you may need to check what type or class a given object is. You may also want to see if a particular object is an instance of a particular class. There are two built-in functions for doing this type of thing in Python. These are the type() function, and the isinstance() function. Everything in Python is an object, and the type() function will tell you what type of object a given variable is.…