Method Overriding - Definition

• When a child class defines a method with the same name and parameters as a method in its parent class.
• The child class method replaces (overrides) the parent class method when called on a child instance.
• Used for runtime polymorphism and customizing inherited behavior.

Method Overriding - Key Points

• Method name and parameters must be the same as in the parent class.
• Child class method takes priority when called on a child object.
• super() can be used to call the parent’s method inside the child’s overridden method.
• Overriding only applies to methods, not attributes (though attributes can be shadowed separately).

Method Overriding - Basic Example

class Parent:
    def show(self):
        print("This is the Parent class method")

class Child(Parent):
    def show(self):
        print("This is the Child class method (Overridden)")

c = Child()
c.show()  # Output: This is the Child class method (Overridden)
      

Method Overriding - Using super()

class Parent:
    def show(self):
        print("Parent class method")

class Child(Parent):
    def show(self):
        print("Child class method starts...")
        super().show()  # Calls parent method
        print("Child class method ends...")

c = Child()
c.show()
# Output:
# Child class method starts...
# Parent class method
# Child class method ends...
      

Method Overriding - Different Logic

class BankAccount:
    def interest_rate(self):
        return 5  # Default interest rate

class SavingsAccount(BankAccount):
    def interest_rate(self):
        return 7  # Higher interest rate

sa = SavingsAccount()
print(sa.interest_rate())  # Output: 7
      

Method Overriding - Multiple Inheritance

class A:
    def display(self):
        print("Class A")

class B(A):
    def display(self):
        print("Class B")

class C(A):
    def display(self):
        print("Class C")

class D(B, C):
    pass

obj = D()
obj.display()       # Output: Class B (MRO: D -> B -> C -> A)
print(D.mro())      # Shows Method Resolution Order