Why OOPs In Python?

Classes, Objects and Constructors

Instance and Class Variables

Class Methods In Python

Class Methods As Alternative Constructor

Static Methods In Python oops

Inheritance In Python oops

[Hindi] Magic/Dunder Methods In Python? | Object Oriented Programming Using Python Tutorial #8

[Hindi] Property Decorators, Setters & Deleters? | Object Oriented Programming Using Python #9

In the previous article, we have discussed classes, instance variables, and methods. In this article, we are going to study Inheritance. Inheritance is considered one of the four pillars of object-oriented programming. So, let us, deep-dive into this concept.
<h4>What is Inheritance?</h4>
<ul>
<li>Inheritance allows us to define a class that inherits all the methods and properties from another class. The parent class is the class being inherited from, also called the base class. The child class is the class that inherits from another class, also called the derived class.</li>
<li>The question is, why we want to inherit a class? Why can't we simply copy and paste the same code for a different class? The straightforward answer to this question is that we do not want to copy and paste the code because it violates the first rule of programming, i.e., Do Not Repeat Yourself.</li>
<li>The concept of inheritance was introduced to deal with the scenarios where we want to use the methods and variables of a class in some other class.</li>
<li>Inheritance increases the reusability of a code so that we don&rsquo;t have to write the same code again and again.</li>
</ul>
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In the previous tutorial, we created a class Employee with class methods, static methods, and instance variables. Below is the code for the same:
<pre class="language-python"><code>class Employee:
 increment = 1.5
 no_of_employe= 0
 def __init__(self,fname,lname,salary): 
 self.fname=fname
 self.lname=lname
 self.salary=salary
 self.increment=1.4
 Employee.no_of_employe +=1
 
 def increase(self):
 self.salary = int(self.salary * Employee.increment)
 
 @classmethod
 def change_increment(cls,amount):
 cls.increment = amount
 
#shubham =Employee("shubham", "jackson", "88000")
#rohan = Employee("rohan","das",4400)</code></pre>
To understand the concept of inheritance, we will create a new class named Programmer that will inherit the Employee class. So, let's get started.
<h4>Creating a new class:</h4>
<pre class="language-python"><code>class Programmer(Employee):
 pass</code></pre>
<ol style="list-style-type: lower-alpha;">
<li>Here, the class Programmer will inherit all the methods and functions of class Employee as we have passed Employee as the parameter in Programmer class.</li>
<li>Let us create an object of class Programmer: 
<pre class="language-python"><code>harry = Programmer("harry","jackson",99000)
</code></pre>
<h5>Printing the output:</h5>
<pre class="language-python"><code>print(harry.fname)
print(harry.lname)
print(harry.salary)</code></pre>
<h5>Output:</h5>
<pre class="language-python"><code>harry
jackson
99000
</code></pre>
Here, the Programmer class has inherited/copied all the methods, functions, and working of a class Employee. Like any other class, we can also create constructors, methods, and attributes for the Programmer class. So, let's do it.</li>
</ol>
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<h4>Creating a constructor: </h4>
<pre class="language-python"><code>def __init__(self,lname,fname,salary,proglang,exp):
 super.__init__(fname, lname, salary)
 self.proglang = proglang
 self.exp = exp
</code></pre>
<ul>
<li>In the above code, we've used super.__init__&nbsp; to call the __init__ of the super class.</li>
<li>We've also created two instance variables named prolang and exp for the Programmer class.</li>
</ul>
<h5>Creating an object of the programmer class:</h5>
<pre class="language-python"><code>abhishek = Programmer("abhishek","Pathak",10000,"python","1 yrs")
</code></pre>
In the above code: 
<ul>
<li> fname = &ldquo;abhishek&rdquo;</li>
<li> lname = &ldquo;Pathak&rdquo;</li>
<li> Salary = 10000</li>
<li> proglang = &ldquo;python&rdquo;</li>
<li> exp = &ldquo;1 yrs&rdquo;</li>
</ul>
<h5>Getting the output:</h5>
<pre class="language-python"><code>print(abhishek.fname)
print(abhishek.lname)
print(abhishek.salary)
print(abhishek.proglang)
print(abhishek.exp)</code></pre>
<h5>Output:</h5>
<pre class="language-python"><code>abhishek
Pathak
10000
python
1 yrs</code></pre>
This tutorial ends here, and I will see you in the next tutorial. Till then, keep coding and keep learning.