Python Decorators and Closures 3

Question 1

What does @staticmethod mean when applied to a method inside a class?

Accepted Answer

The method receives no implicit first argument — no self or cls

Answer

The method can only be called once per instance

Answer

The method is automatically inherited by all subclasses

Answer

The method is private and cannot be called from outside the class

Question 2

What is the key difference between @classmethod and @staticmethod?

Accepted Answer

@classmethod receives the class as its first argument (cls), @staticmethod receives no implicit argument

Answer

There is no practical difference between them

Answer

@staticmethod receives the class, @classmethod receives the instance

Answer

@classmethod can only be used with abstract base classes

Question 3

What is the output of the following code?

def make_multiplier(n):
    def multiplier(x):
        return x * n
    return multiplier

double = make_multiplier(2)
triple = make_multiplier(3)
print(double(5), triple(5))

Accepted Answer

10 15

Answer

10 10

Answer

5 5

Answer

Error: n is not defined

Question 4

What is a common use of decorators in Python web frameworks like Flask?

Accepted Answer

Route registration — mapping URLs to handler functions with @app.route

Answer

Defining database schemas

Answer

Rendering HTML templates automatically

Answer

Managing database connection pools

Question 5

What happens to a decorated function if you do not use functools.wraps inside the wrapper?

Accepted Answer

The wrapped function loses its original metadata such as __name__ and __doc__

Answer

The decorator will not work at all

Answer

The decorator raises a TypeError at call time

Answer

The function runs significantly slower

Question 6

Which description best defines memoization as implemented with a decorator?

Accepted Answer

A decorator that caches function results keyed by arguments to avoid redundant computation

Answer

A decorator that makes a function execute in parallel threads

Answer

A decorator that logs all function calls with timestamps

Answer

A decorator that converts a function into a generator

Question 7

Which built-in Python module provides the lru_cache decorator for automatic memoization?

Accepted Answer

functools

Answer

itertools

Answer

collections

Answer

operator