Python super()

Difficulty Level : Basic
Last Updated : 07 Jan, 2021

One of the important OOP features is Inheritance in Python. When a class inherits some or all of the behaviors from another class is known as Inheritance. In such a case, the inherited class is the subclass and the latter class is the parent class.
In an inherited subclass, a parent class can be referred to with the use of the super() function. The super function returns a temporary object of the superclass that allows access to all of its methods to its child class.

Note: For more information, refer to Inheritance in Python

Furthermore, The benefits of using a super function are:-

Need not remember or specify the parent class name to access its methods. This function can be used both in single and multiple inheritances.
This implements modularity (isolating changes) and code reusability as there is no need to rewrite the entire function.
Super function in Python is called dynamically because Python is a dynamic language unlike other languages.

There are 3 constraints to use the super function:-

The class and its methods which are referred by the super function
The arguments of the super function and the called function should match.
Every occurrence of the method must include super() after you use it.

Super function in single inheritance

Example: Let’s take an example of animals. Dogs, cats and cows are part of animals. They also share common characteristics like –

They are mammals.
They have a tail and four legs.
They are domestic animals.

So, the classes dogs, cats and horses are subclass of animal class. This is an example of single inheritance because many subclass are inherited from a single parent class.

Python3

# Python program to demonstrate
# super function
 
 
class Animals:
     
    # Initializing constructor
    def __init__(self):
        self.legs = 4
        self.domestic = True
        self.tail = True
        self.mammals = True
     
    def isMammal(self):
        if self.mammals:
            print("It is a mammal.")
     
    def isDomestic(self):
        if self.domestic:
            print("It is a domestic animal.")
     
class Dogs(Animals):
    def __init__(self):
        super().__init__()
 
    def isMammal(self):
        super().isMammal()
 
class Horses(Animals):
    def __init__(self):
        super().__init__()
 
    def hasTailandLegs(self):
        if self.tail and self.legs == 4:
            print("Has legs and tail")
 
# Driver code
Tom = Dogs()
Tom.isMammal()
Bruno = Horses()
Bruno.hasTailandLegs()

Output:

It is a mammal.
Has legs and tail

Super function in multiple inheritance

Example: Let’s take another example. Suppose a class canfly and canswim inherit from a mammal class and these classes are inherited by the animal class. So the animal class inherits from the multiple base classes. Let’s see the use of super in this case.

Python3

class Mammal():
     
    def __init__(self, name):
        print(name, "Is a mammal")
         
class canFly(Mammal):
     
    def __init__(self, canFly_name):
        print(canFly_name, "cannot fly")
         
        # Calling Parent class
        # Constructor
        super().__init__(canFly_name)
             
class canSwim(Mammal):
     
    def __init__(self, canSwim_name):
         
        print(canSwim_name, "cannot swim")
             
        super().__init__(canSwim_name)
         
class Animal(canFly, canSwim):
     
    def __init__(self, name):
         
        # Calling the contructor
        # of both thr parent
        # class in the order of 
        # their inheritance
        super().__init__(name)
 
 
# Driver Code
Carol = Animal("Dog")

Output:

Dog cannot fly
Dog cannot swim
Dog Is a mammal

The class Animal inherits from two-parent classes – canFly and canSwim. So, the subclass instance Carol can access both of the parent class constructors.

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