Classes and Objects in Python

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Python is an object-oriented, high-level programming language. Object-oriented means that objects are the fundamental building blocks. A property is an attribute of an object. A method is a function associated with an object. A Class is like an object constructor or a “blueprint” for creating objects. Both properties and methods are called “attributes”. This article will help you to understand Classes and Objects in Python.

While all this may seem confusing; these are some of the very basic terms one needs to know before starting to program in Python. While learning how to program in Python is a challenge, it is worthwhile to learn how to use Python because of how easy it is to create and read. Python is a lot like other languages in that you have to use many different variables to perform different actions, but Python works faster than other languages. These classes have properties and methods, and the methods have attributes. It’s a lot like a recipe for baking – you have a list of ingredients, the steps for creating the object, and the outcome of creating the object. In this article, we’ll show you what these things are, how they work, and some examples of them. 

Classes

A class is a base on which a method executes; it’s a blueprint of an object. It is a user-defined data type that allows one to create multiple objects that contain similar data attributes and methods. These objects can then be used to create instances. An instance is an object that is created from a class. A class can contain variables, constants, as well as other methods which can be executed by the class object. If you are familiar with C++, Java, or PHP, a class is not unlike structs. A basic example of a class is shown below:

class MyClass:
  name = 'python'
  x = 5

The class statement creates a new class definition. The name of the class immediately follows the keyword class followed by a colon as shown.

Objects

Objects are anything that nails down some specific piece of state and gives you procedures for manipulating it. There’s a good chance that you’ve already been using objects at least implicitly, as many built-in types in Python behave like objects (e.g., integers, strings, lists). You may also have heard the word “interface” thrown around now and then, perhaps with a dismissive connotation, perhaps not. For now, all you really need to know is that they’re an object thing too. 

We can use class MyClass to create an object named p1, and print the value of x:

p1 = MyClass()
print(p1.x) 

Attributes and Methods in Python:

A class by itself is of no use. A class is a collection of related code called attributes. The way you work with a class and its attributes is by defining a series of operations called functions, which are associated with specific values contained within the attributes. Classes only provide structure and an abstracted form of storing data.

For example, you can define a class with the name MyClass and add a variable called name and put some string in it, as shown:

class MyClass:
    name = "python"

Class attributes are variables of a class that are shared between all of its instances. This is called object instantiation. You will then be able to access the attributes (variable) that are present inside the class using the dot “.” operator. For example, in the MyClass example above, you can access the attribute name of the class MyClass.

MyClass = MyClass()

print(MyClass.name)
python

Similarly, if an attribute (a variable) is meant to be associated with an instance of a class, then you must define a function within your class that will access that attribute to perform various functions. These functions are called methods and when you’re defining them you should generally provide the first argument with the self keyword as it’s a special type of the local variable used to refer to itself within that given method.

For example, you can define a class MyClass, which has one attribute name and one method change_name. The method change name will take in an argument new_name along with the keyword self.

class MyClass:
    name = "python"
def change_name(self, new_name):
    self.name = new_name

Now, you can instantiate this class MyClass with a variable MyClass and then change the name with the method change_name.

MyClass = MyClass()

print(MyClass.name)
python

MyClass.change_name("anaconda")
print(MyClass.name)
anaconda

Advanced Object-Oriented Features

Python is distinguished by being one of the main languages that you can use to create OOP. Python can efficiently modify the behavior of objects. For example, one can reroute attributes and methods to new local variables and otherwise modify classes on demand. Obviously, one should be thoroughly conversant in OO programming concepts before attempting this. Also, some of Python’s more professional features, such as creating helper classes from inside functions and having class instances create other instances at runtime, lend themselves best to very advanced uses of the popular language.

Multiple Inheritance

Multiple inheritances allows derived classes to inherit the properties of more than one base class. The derived class is known as a multiple derived class. This can also be called a case of multiple inheritances. The derived class is bound to inherit the properties of all the base classes.

An example of this would be:

class Car:
    def go(self):
        print('Going')


class Flyable:
    def fly(self):
        print('Flying')

class FlyingCar(Flyable, Car):
    pass

Here I have defined classes Car and Flyable that have the go() and Fly() methods respectively. Then there is a FlyingCar class that inherits from both Car and Flyable classes; it reuses the methods from those classes. It means you can call the go() and fly() methods together on an instance of the FlyingCar.

Like this:

if __name__ == '__main__':
    fc = FlyingCar()
    fc.go()
    fc.fly()

Final Words

In this article, we’ve discussed various types of OOP Concepts, Classes and Objects in Python in detail with examples. We’ve also tried to answer some basic questions like What is OOP in Python? What are the different types of Python OOP Concepts? If you’ve any questions, please feel free to ask them, we’d be happy to help you further. 

Here are some useful tutorials that you can read:

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