Constructor and Destructor

Constructor

Constructor is special function which invokes automatically at the time of object creation.

Syntax :

constructor_syntax.py
def __init__ (self):

Example :

constructor.py
class ATM:

  def normal_function(self):
    print("Normal Function Called...")

  def __init__(self):
    print("Welcome to BOB !")

obj = ATM()
obj.normal_function()

Output :

Welcome to BOB !
Normal Function Called...

Example Exaplanation :

In the above example, we create class ATM in this class create function normal_function() with a self parameter then create a constructor with a self parameter & print massage, create the object for ATM that is obj and call function normal_function().

Example :

constructor.py
class sample:
  def showSample(self, param):
    print("This is sample",param)

  def __init__(self):
    print("Constructer Called..")

obj = sample()
obj.showSample("code")

Output :

Constructer Called..
This is sample code

Destructor

Destructor invokes when object goes out of scope .

Syntax :

destructor_syntax.py
def __del__(self):

Example :

destructor.py
class ATM:

  def normal_function(self):
    print("Normal Function Called...")

  def __init__(self):
    print("Welcome to BOB !")

  def __del__(self):
    print("Destructor Called...")

obj = ATM()
obj.normal_function()

Output :

Welcome to BOB !
Normal Function Called...
Destructor Called...

Example :

destructor.py
class ATM:

  def normal_function(self):
    print("Normal Function Called...")

  def __init__(self):
    print("Welcome to BOB !")

  def __del__(self):
    print("Destructor Called ...")

obj = ATM()
obj.normal_function()
del obj

Output :

Welcome to BOB ! Normal Function Called... Destructor Called ...

Constructor​

Destructor​

Constructor

Destructor