Object-Oriented Programming Basics Flashcards

What is the purpose of a `@staticmethod` in Python?

Answer: It cannot access the class or instance

Static methods belong to the class namespace but receive neither `self` nor `cls`, so they cannot modify class or instance state.

What does `isinstance(obj, MyClass)` return?

Answer: True if obj is an instance of MyClass or any of its subclasses

`isinstance()` returns `True` for the specified class and all its subclasses, supporting polymorphic checks.

In Python, what is the Method Resolution Order (MRO)?

Answer: The order Python searches base classes when resolving a method call

MRO, computed by the C3 linearization algorithm, determines which class's method is invoked in multiple-inheritance hierarchies.

What does the `@property` decorator do?

Answer: Allows a method to be accessed like an attribute

`@property` lets you define getter logic for an attribute so callers use `obj.name` instead of `obj.get_name()`.

Which of the following demonstrates composition over inheritance?

Answer: class Car: def __init__(self): self.engine = Engine()

Composition means a class contains an instance of another class as an attribute, favoring 'has-a' over 'is-a' relationships.

What happens when you call `del obj.attr` where `attr` has a `@property` setter but no deleter?

Answer: Python raises an AttributeError

Without a `@attr.deleter` defined, attempting to delete the property raises `AttributeError: can't delete attribute`.

Which dunder method allows instances to be used as callables (e.g., `obj()`)?

Answer: __call__

Defining `__call__` on a class makes its instances callable, executing the `__call__` body when `obj()` is used.