POC Object-Oriented Programming in Python 5

Question 1

What is a mixin in Python OOP?

Accepted Answer

A class designed to provide optional methods to other classes via multiple inheritance without standing alone

Answer

Mixins are small, focused classes providing reusable behavior, combined via multiple inheritance without being used independently.

Question 2

What is the difference between `__repr__` and `__str__`?

Accepted Answer

`__repr__` is for developers (unambiguous), `__str__` is for end-users (readable)

Answer

`__repr__` should return an unambiguous developer-facing string; `__str__` returns a readable user-facing string.

Question 3

Which of the following demonstrates operator overloading in Python?

Accepted Answer

Defining `__add__` in a class so `+` works on custom objects

Answer

Operator overloading is achieved by implementing dunder methods like `__add__`, `__mul__`, etc., in a class.

Question 4

What happens when you use `__slots__` in a Python class?

Accepted Answer

It restricts the object to only the listed attributes, saving memory

Answer

`__slots__` prevents creation of a `__dict__` per instance and restricts attribute names, reducing memory usage.

Question 5

In Python, what is composition (as opposed to inheritance)?

Accepted Answer

Building a class that contains instances of other classes as attributes, rather than inheriting from them

Answer

Composition models a 'has-a' relationship — a class holds references to objects of other classes rather than extending them.

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