Super keyword in python

• super can invoke parent class method
• super can invoke parent class constructor
• super can invoke parent class variable

Super can invoke parent class method.calling Super class methods : by using super()

class A10:
	def displayInsatneMethod1(self):
		print("Instance Method A10")
class B10(A10):
	def displayInsatneMethod2(self):
		print("Instance Method B10")
		super().displayInsatneMethod1()	
b10=B10();#child class Object
b10.displayInsatneMethod2()

Instance Method B10
Instance Method A10

Super can invoke parent class method with argument

class A10:
	def displayInsatneMethod1(self,fname,lname):
		print("Instance Method A10 :", fname ,lname )
class B10(A10):
	def displayInsatneMethod2(self):
		print("Instance Method B10")
		super().displayInsatneMethod1("ABC","XYZ")	
b10=B10();#child class Object
b10.displayInsatneMethod2()

Instance Method B10
Instance Method A10 : ABC XYZ

Super invoke parent class Variable with different name

comName="XYZ"
localtion="UP"
class A10:
	comName1="JBB"
	localtion1="US"
	
class B10(A10):

	comName2="APP"
	localtion2="California"

	def displayInsatneMethod2(self,comName3,localtion3):
		#as class variable
		print(self.comName1+" "+self.localtion1)
		#as class variable
		print(self.comName2+" "+self.localtion2)
		#as globals variable
		print(globals()['comName']+" "+globals()['localtion'])
		print(comName3+" "+localtion3)#as local variable
b10=B10();#child class Object
b10.displayInsatneMethod2("JBBAPP","Germany")		

JBB US
APP California
XYZ UP
JBBAPP Germany

Super invoke parent class, class variable with same name

comName="XYZ"
localtion="UP"
class A10:
	comName="JBB"
	localtion="US"
	
class B10(A10):

	comName="APP"
	localtion="California"

	def displayInsatneMethod2(self,comName3,localtion3):
		#current class variable comName and localtion
		print(self.comName+" "+self.localtion)
		#parent class variable comName and localtion
		print(super().comName+" "+super().localtion)
		#as globals variable
		print(globals()['comName']+" "+globals()['localtion'])
		print(comName3+" "+localtion3)#as local variable
b10=B10();#child class Object
b10.displayInsatneMethod2("JBBAPP","Germany")	

APP California
JBB US
XYZ UP
JBBAPP Germany

Super invoke parent class default constructor

class A10:

	def __init__(self):
		print("Default Constructor A10")

class B10(A10):

	def __init__(self):
		print("Default Constructor B10")
		super().__init__()	

b10=B10();#child class Object

Default Constructor B10
Default Constructor A10

Super invoke parent class parameterized constructor

class A10:

	def __init__(self,fname,lname):
		print("Default Constructor A10 :", fname, lname)

class B10(A10):

	def __init__(self):
		print("Default Constructor B10")
		super().__init__("JBB","Pvt. Ltd.")	

b10=B10();#child class Object

Default Constructor B10
Default Constructor A10 : JBB Pvt. Ltd.

Parent class Constructor call multiple time form child class

class A10:
	
	def __init__(self):
		print("parent class Constructor")

class B10(A10):
	
	def __init__(self):
		super().__init__()
		print("child class Constructor")
		super().__init__()
		super().__init__()

b10=B10();#child class Object

parent class Constructor
child class Constructor
parent class Constructor
parent class Constructor

Two way to call parent class constructor

• by super keyword
• by parent class Name :

class A10:
	
	def __init__(self):
		print("parent class Constructor")

class B10(A10):
	
	def __init__(self):
		super().__init__()
		print("child class Constructor")
b10=B10();#child class Object

parent class Constructor
child class Constructor

Here if you are calling the parent class constructor by using class Name in this case frist args must be self args

class A10:
	
	def __init__(self,email):
		print("parent class Constructor",email)

class B10(A10):
	
	def __init__(self):
		super().__init__("ashu@gmail.com")
		print("1 child class Constructor")
		A10.__init__(self,"arun@gmail.com")
		print("2 child class Constructor")

b10=B10();#child class Object

parent class Constructor ashu@gmail.com
1 child class Constructor
parent class Constructor arun@gmail.com
2 child class Constructor

copy constructor

class HrEmploye:
	
	def __init__(self,fn,ln):
		self.fn=fn
		self.ln=ln
class Employee(HrEmploye):

	def __init__(self,fn,ln,em):
		#super().__init__(fn,ln)
		#OR
		HrEmploye.__init__(self,fn,ln)
		self.em=em

	def display(self):
		print("Fn:",self.fn," Ln:",self.ln," Em:",self.em)
		print("Fn:{} Ln:{} Em:{}".format(self.fn,self.ln,self.em))

e1=Employee("Ashutosh","Mishra","ashumishra9015@gmail.com")
e1.display()

Fn: Ashutosh  Ln: Mishra  Em: ashumishra9015@gmail.com
Fn:Ashutosh Ln:Mishra Em:ashumishra9015@gmail.com