Why is __init__() always called after __new__() in python?
Python is having special type of methods called magic methods named with preceded and double underscores.
if we want to talk about magic method __new__ then obviously will also need to talk about __init__ method.
The magic method __new__ will be called when instance is being created.where as
__init__ method will be called to initialize instance when you are creating instance.
Example
Live Demo
class X():
_dict = dict()
def __new__(self):
if 'data' in X._dict:
print ("new instance Exists")
return X._dict['data']
else:
print ("magic method New")
return super(X, self).__new__(self)
def __init__(self):
print ("instantiation")
X._dict['data'] = self
print ("")
a1 = X()
a2 = X()
a3 = X()Output
magic method New
instantiation
new instance Exists
instantiation
new instance Exists
instantiation
important to remember :
The __init__ function is called a constructor, or initializer, and is automatically called when you create a new instance of a class.
Published on 23-May-2019 15:27:17
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