Class Inheritance Advanced

In Python a class can inherit one or more classes.

Inheriting multiple classes

Let's look at the following example:

class A: def printA(self): print("A") class B: def printB(self): print("B") class C(A, B): def printC(self): print("C") cObject = C() cObject.printA() cObject.printB() cObject.printC()

Output:

A B C

Explanation:

• At line 9 class C inherits two classes - A and B.
• Because of that class C has 3 members functions - printA, printB and printC.

Multilevel Inheritance

A class can inherit a class that inherits other class. A long chain can be formed.

Each child in the chain inherits functions and members from the ones before it (it's parents grandparents etc...).

Here's an example:

class A: def getA(self): return "A" class B (A): def getB(self): return "B" class C (B): def getC(self): return "C" class D (C): def getD(self): return "D" sampleObject = D() print(sampleObject.getA()) print(sampleObject.getB()) print(sampleObject.getC()) print(sampleObject.getD())

Output:

A B C D

Explanation:

• There is an inheritance chain: A is inherited by B. B is inherited by C. C is inherited by D.
• At line 5 class B inherits class A.
• At line 9 class C inherits class B. Class C inherits the members from B and A. So class C has functions - getA, getB and getC.
• At line 13 class D inherits class C. Class D is at the bottom of the inherit chain. So it inherits members from A, B and C. Class D has functions getA, getB, getC and getD.