Object-Oriented Programming Basics Flashcards

How do you define a class method (not an instance method) in Python?

Answer: Use @classmethod decorator with 'cls' as first parameter

@classmethod receives the class as the first argument (conventionally named 'cls') and can access or modify class state.

What is method overriding in Python?

Answer: A child class provides its own implementation of a method inherited from the parent

Method overriding lets a subclass redefine an inherited method, replacing the parent's behavior with its own.

What is the output of: class A: x = 10 a1 = A() A.x = 20 print(a1.x)

Answer: 20

a1.x resolves to the class attribute A.x because no instance attribute 'x' was set on a1; after A.x = 20, it reads 20.

Which statement about Python's __str__ method is correct?

Answer: It is called by str() and print() to get a human-readable string

__str__ should return a user-friendly string; Python calls it automatically when you use str(obj) or print(obj).

What does super() do in a subclass?

Answer: Returns a proxy that delegates method calls to the parent class

super() returns a proxy object that forwards method calls to the next class in the MRO, typically the parent class.

How do you create a static method in Python?

Answer: Use the @staticmethod decorator and no 'self' or 'cls' parameter

@staticmethod marks a method that takes neither 'self' nor 'cls', behaving like a regular function scoped to the class.

What is multiple inheritance in Python?

Answer: A class derives from more than one parent class

Python supports multiple inheritance with class Child(Parent1, Parent2):, and uses the MRO to resolve method lookups.