Decorators and Closures Flashcards

What is a decorator in Python?

Answer: A function that modifies or extends the behavior of another function

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

Which symbol is used in Python's decorator syntax?

Answer: @

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

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

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

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.

What is a closure in Python?

Answer: A function that captures and remembers variables from its enclosing scope

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

What will the following code print? def outer(): x = 10 def inner(): return x return inner f = outer() print(f())

Answer: 10

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.

What does the @property decorator do in Python?

Answer: Allows a method to be accessed like an attribute

The @property decorator allows you to define methods that can be accessed like attributes, enabling getter behavior without explicit method calls.

Which of the following is NOT a built-in Python decorator?

Answer: @private

@private is not a built-in Python decorator; Python does not have built-in access modifier decorators, though @staticmethod, @classmethod, and @property are all built-in.