Python
In this tutorial we will learn about inheritance in Python.
Inheritance is one of the core concepts of OOP - Object Oriented Programming. It helps us to create hierarchy.
Inheritance is a concept were a child class inherits the properties and methods from the parent class.
The class that is used to create other classes is called the parent class or super class.
The class that inherits the attributes and methods of the parent class is called the sub class or child class.
Following is the syntax of inheritance in Python.
# parent class class ParentClass: # # some attributes of the parent class # # # some methods of the parent class # class ChildClass(ParentClass): # # some attributes of the child class # # # some methods of the child class #
Note! The attributes and methods of the ParentClass is inherited by the ChildClass.
ParentClass
ChildClass
In the following Python program we have a parent class Employee and a child class Manager.
# parent class class Employee: def __init__(self, id, name): print("Hello from Employee.__init__()") self.id = id self.name = name def employeeDetail(self): print("ID: %s" %self.id) print("Name: %s" %self.name) # child class class Manager(Employee): def __init__(self, id, name, project): super().__init__(id, name) print("Hello from Manager.__init__()") self.project = project def projectDetail(self): print("Project: %s" %self.project) # object of Manager class obj = Manager(1, 'Jane Doe', 'Android App') # output print("-----Manager Detail-----") obj.employeeDetail() print("-----Project Detail-----") obj.projectDetail()
The above code will print the following output.
Hello from Employee.__init__() Hello from Manager.__init__() -----Manager Detail----- ID: 1 Name: Jane Doe -----Project Detail----- Project: Android App
We have the parent class Employee and the child class Manager which inherits attributes and methods of the parent class.
Employee
Manager
In this class we have the __init__ method that takes two arguments id and name of the employee which we are saving using the self keyword.
__init__
id
name
self
Then we have the employeeDetail method that prints the detail of the employee.
employeeDetail
This class also includes the __init__ method and it takes three arguments id, name and project of the employee.
project
Using the super method in the child class we call the __init__ method of the parent class.
super
Inside the __init__ method of the Manager class we are calling the __init__ method of the Employee class and passing the id and name value.
We are assigning the value of project to the instance attribute project using the self keyword.
Then, there is the projectDetail method that prints out the project name.
projectDetail
We create an object of the Manager class which inherits all the properties and methods of the Employee class.
While instantiating an object of the Manager class we are passing the id, name and project name of the employee.
Finally, we are calling the employeeDetail and projectDetail methods which prints the values set for the employee.