Python Decorators and Closures

Question 1

What is a decorator in Python?

Accepted Answer

A function that modifies or extends the behavior of another function

Answer

A decorator is a function that takes another function as input and returns a modified or extended version of it.

Question 2

Which symbol is used in Python's decorator syntax?

Accepted Answer

@

Answer

The @ symbol placed before a function definition applies the decorator to that function.

Question 3

What does functools.wraps do when used inside a decorator?

Accepted Answer

Copies the original function's metadata (like __name__ and __doc__) to the wrapper

Answer

functools.wraps preserves the original function's metadata such as its name and docstring, which would otherwise be replaced by the wrapper function's metadata.

Question 4

What is a closure in Python?

Accepted Answer

A function that captures and remembers variables from its enclosing scope

Answer

A closure is an inner function that remembers the values from its enclosing scope even when execution has moved outside that scope.

Question 5

What will the following code print?

def outer():
    x = 10
    def inner():
        return x
    return inner

f = outer()
print(f())

Accepted Answer

10

Answer

The inner function forms a closure over variable x from the outer function's scope, so it can access and return x even after outer has finished executing.

Python Practice Test

Python Practice Test

Python Decorators and Closures