Python Decorators - Practice Questions 2026 - Free Online Course

Master Python Decorators: Comprehensive Practice Exams

Are you looking to master one of Python's most powerful and elegant features? Python Decorators are essential for writing clean, reusable, and efficient code. Whether you are preparing for a technical interview or looking to enhance your professional development skills, these practice exams are designed to transform you from a beginner to an expert.

Why Serious Learners Choose These Practice Exams

Serious learners understand that watching a video is only the first step. True mastery comes from testing your knowledge against challenging, varied scenarios. This course provides a safe environment to fail, learn, and improve. By engaging with these practice tests, you ensure that the logic behind higher-order functions and closures becomes second nature. Our question bank is built to simulate real-world coding hurdles, ensuring you are not just memorizing syntax but understanding the underlying architecture of the Python language.

Course Structure

Our curriculum is divided into six logical pillars to ensure a smooth learning curve:

Basics / Foundations: This section focuses on the prerequisites of decorators. You will be tested on first-class functions, inner functions, and how scope works in Python. Understanding how a function can be passed as an argument is the bedrock of everything that follows.
Core Concepts: Here, we dive into the @decorator syntax. You will practice wrapping simple functions, understanding the execution flow, and ensuring that the identity of the decorated function remains intact using tools like functools.wraps.
Intermediate Concepts: This module introduces complexity by challenging you with decorators that accept arguments. You will learn the "triple-nested" function structure required to pass configuration parameters into your decorators.
Advanced Concepts: We push the boundaries by exploring Class-based decorators, stacking multiple decorators on a single function, and decorating methods within a class. This is where you learn to handle the self and cls arguments correctly.
Real-world Scenarios: Practice exams in this section focus on practical applications such as logging, timing execution, rate-limiting, and authentication checks. These are the exact types of decorators you will encounter in professional frameworks like Flask, Django, or FastAPI.
Mixed Revision / Final Test: A comprehensive evaluation that pulls questions from every previous section. This final stage is designed to build your confidence and ensure long-term retention of the material.

Sample Practice Questions

QUESTION 1

What is the primary purpose of using functools.wraps(func) when creating a custom decorator?

OPTION 1: To ensure the decorator runs faster by caching the results.
OPTION 2: To allow the decorated function to accept an unlimited number of arguments.
OPTION 3: To preserve the original function's metadata, such as its name and docstring.
OPTION 4: To automatically handle exceptions raised by the wrapped function.
OPTION 5: To convert a function-based decorator into a class-based decorator.

CORRECT ANSWER: OPTION 3

CORRECT ANSWER EXPLANATION: When you wrap a function with a decorator, the original function is replaced by the wrapper function. Without functools.wraps, if you check my_function.__name__, it would return 'wrapper' instead of 'my_function'. Using @wraps(func) copies the original metadata back to the wrapper.

WRONG ANSWERS EXPLANATION:

OPTION 1: Incorrect. functools.wraps does not perform caching; that is the role of functools.lru_cache.
OPTION 2: Incorrect. Handling arguments is done via *args and **kwargs within the wrapper function, not by the wraps utility.
OPTION 4: Incorrect. wraps does not provide error-handling logic; you must write try-except blocks manually.
OPTION 5: Incorrect. wraps is a decorator itself used within both function and class decorators, but it does not change the type of the decorator structure.

QUESTION 2

What will be the output of the following code?

Python

def my_dec(func):

def wrapper():

return func() + " world"

return wrapper

@my_dec

def greet():

return "hello"

print(greet())

OPTION 1: hello
OPTION 2: world
OPTION 3: hello world
OPTION 4: AttributeError
OPTION 5: NameError

CORRECT ANSWER: OPTION 3

CORRECT ANSWER EXPLANATION:

The decorator my_dec takes the function greet. Inside the wrapper, it calls the original function (which returns "hello") and concatenates it with the string " world". When greet() is called, it is actually the wrapper being executed, resulting in "hello world".

WRONG ANSWERS EXPLANATION:

OPTION 1: Incorrect. The decorator has modified the output, so "hello" alone is no longer the result.
OPTION 2: Incorrect. The original function's return value "hello" is included in the wrapper's logic.
OPTION 4: Incorrect. This is valid Python syntax; no attribute errors are triggered.
OPTION 5: Incorrect. All functions and variables are properly defined within the scope.

What You Get With This Course

Welcome to the best practice exams to help you prepare for your Python Decorators.