Decorators

What You’ll Learn

You’ll learn how to use decorators to modify or enhance the behavior of a function without changing its source code.

Higher-Order Functions

In Python, functions are first-class objects. This means functions can be passed around and used as arguments, just like any other object (string, int, float, list, and so on).

What is a Decorator?

A decorator takes in a function, adds some functionality, and returns it. It’s marked with the @ symbol.

# The Decorator
def my_decorator(func):
    def wrapper():
        print("Something is happening before the function is called.")
        func()
        print("Something is happening after the function is called.")
    return wrapper

# Applying the Decorator
@my_decorator
def say_hello():
    print("Hello!")

# Calling the function
say_hello()

Expected Output:

Something is happening before the function is called.
Hello!
Something is happening after the function is called.

Decorators are widely used in frameworks like Flask or Django to check if a user is logged in before allowing them to view a page.