multipleinheritance.md

Multiple Inheritance

Introduction

• When a single child class inherit's from multiple parent classes, it is called as Multiple inheritances.
• We specify all parent Classes as a comma-separated list in child class.
• if two-parent class have the same method and you calling that method using the object of child class then the method call is dependent on which class is initialized first.

Example:

def __init__(self):
    A.__init(self)
    B.__init(self)

here, class, A method is called First if that method not present in class A then it will execute it from class B

def __init__(self):
    B.__init(self)
    A.__init(self)

Here class B method is called First

Algorithm

1. create a parent class

class A:

2. Define methods and attributes

def __init__(self):
    self.varsa="I am from class A"

3. Create an Another Parent class named B

class B:

4. Define methods and attributes for class B

def __init__(self):
    self.varsb="I am from class B

5. Now create a child class by inheriting the class A and Class B

class C(A, B):

6. Initialize and call the constructor of class A and Class B in Construction oof class C

def __init__(self):
    A.__init__(self)
    B.__init__(self)

7. Now you can use class A and Class B variables in Class C

def __init__(self):
    A.__init__(self)
    B.__init__(self)
    #Get data of two-parent classes using self 
    print(self.varsa)
    print(self.varsb)

8. Then create an object of child class and call required methods and attributes using it

c1=C()

Example 1

#Parent Class
class A:
    def __init__(self):
      self.name='Python'
      
#Parent Class
class B:
    def __init__(self):
      self.age=20
#Derive from 2 Different class
class C(B,A):
  #Constructor
  def __init__(self):
    B.__init__(self) #First B class is Initilized
    A.__init__(self)
    self.year=2019
  def ShowData(self):
    print(self.name)
    print(self.age)
    print(self.year)
c1=C()

print("Call The ShowData()")
c1.ShowData()

Output:

Call The ShowData()
Python
20
2019

Example 2

#Parent class 1
class A:
    def __init__(self):
      print("class A is Initialized")
      self.name='Python'

#parent class 2
class B():
    def __init__(self):
      print("Class B is Initialized")
      self.age=20

#child class C inherit from parent class 1 and parent class 2
class C(B,A):
  def __init__(self):
    print("Class C is Initialized")

    #initilize constructor B
    B.__init__(self)

    #initilize constructor A
    A.__init__(self)

    #Initilize C instance Variable
    self.year=2019

  def ShowData(self):
    print(self.name)
    print(self.age)
    print(self.year)

#Create an object of C class
c1=C()

#Call method of C Class
c1.ShowData()

Output

Class C is Initialized
Class B is Initialized
class A is Initialized
Python
20
2019