Constructor and Destructor in Python | INIT Method in python | Input and Output Method in Python Class

In Python constructors and destructor are special methods used in class. They allow you to initialize and clean up objects respectively. Here’s how you can define a constructor and destructor in python

Constructor

The constructor method is called when an object is created from a class. It is used to initialize the attributes of the object. In Python the constructor is defined using the __init__ Method

Example

def __init__(self):
        print("init function")

Destructor

The destructor method is called when an object is about to be destroyed or cleaned up. It is used to perform any necessary cleanup operation the object is removed from memory. In python the destructor is defined using the __del__ method

Example

def __del__(self):
        print("destructor call")

Program Source Code:

import os

class student:



    def __init__(self):

        print("init function")

        self.mark = 60

    def show(self):

        objshow = student()

        print("marks :",self.mark)

        os.system("pause")

        objshow.display()

    def display(self):

        print("in display function")

    def __del__(self):

        print("destructor call")



obj1 = student()

os.system("pause")

obj1.show()

os.system("pause")

obj3 = student()

obj3.display()

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Input Method

To handle input, you can define a method in your class that prompts the user for input or accepts input as parameters. This method can then process the input and update the object’s attributes accordingly

Example

def inputMethod(self):
        self.rollno = int(input("Enter Rollno :"))
        self.name = input("Enter Name :")
        self.grade = input("Enter Grade:")

Output Method

To handle output you can define a method in your class that formats and displays the object’s data or returns it as a result

Example

def display(self):
        print("rollno :",self.rollno)
        print("Name :",self.name)
        print("Grade :",self.grade)

Program Source Code

class student:

    def inputMethod(self):

        self.rollno = int(input("Enter Rollno :"))

        self.name = input("Enter Name :")

        self.grade = input("Enter Grade:")

    def display(self):

        print("rollno :",self.rollno)

        print("Name :",self.name)

        print("Grade :",self.grade)

ali = student()

print("--------Input Student Data--------------")

ali.inputMethod()

print("--------Output Student Data--------------")

ali.display()