How to create constructors in python

#1

if init can’t be a constructor how we can create constructors in python like in other languages like c++, java

#2

Hi @shankarmulakalapalli_a9515409b9f01ffd

  • __init__() is not a constructor. The self as the first parameter which is nothing but the object itself i.e object already exists.

  • __init__() is called immediately after the object is created and is used to initialize it.

The answer is __new__()

__new__(cls, *args, **kwargs) # signature

__new__() takes cls as the first parameter which represents the class that is needed to be instantiated, and the compiler automatically provides this parameter at the time of instantiation. args and **kwargs are arguments to be passed.

__new__ () is always called before __init__()

Example:

class Power:

def __new__(cls,*args):
    print("new method")
    print(cls)
    print(args)
    obj = super().__new__(cls)  #create our object and return it
    return obj

def __init__(self,n):         
    print("init method")
    self.n=n

def cal(self):
    return self.n**self.n

p=Power(5)
p.cal()

Output :

new method
<class ‘__main__.Power’>
(5,)
init method
3125

Hope this might helps :slight_smile:

#3

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