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1. Create Class & Object2. Instance vs Class Variables3. Constructors in Python Classes4. Single Inheritance5. Multiple Inheritance6. Multilevel Inheritance7. Polymorphism with Methods8. Method Overloading Simulation9. Encapsulation with Getters/Setters10. Abstraction with ABC11. Operator Overloading12. Custom Iterator13. Class Methods14. Static Methods15. Composition Example16. Aggregation Example17. Private Variables18. Magic Methods Overview19. Object Cloning20. Custom Exceptions21. Class Decorator22. Prototype Pattern23. Singleton Pattern24. MRO (Method Resolution Order) Demo25. Polymorphism (Duck Typing)

MRO (Method Resolution Order) Demo in Python

ClassName.__mro__ is the lookup order. Print it when diamond inheritance gets weird.

IntermediateObject-Oriented ProgramsExample 24 of 25
mro-method-resolution-order-demo.py
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1# Program to demonstrate method resolution order (MRO)
2

3class A:
4    def who_am_i(self):
5        print("I am A")
6

7class B(A):
8    def who_am_i(self):
9        print("I am B")
10

11class C(A):
12    def who_am_i(self):
13        print("I am C")
14

15class D(B, C):
16    pass
17

18d = D()
19d.who_am_i()
20print(D.mro())

Output

I am B
[<class '__main__.D'>, <class '__main__.B'>, <class '__main__.C'>, <class '__main__.A'>, <class 'object'>]

What's going on

D inherits from B and C; Python uses the MRO list to decide which 'who_am_i' implementation to call.

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