Python Decorator

 In Python, a decorator is a design pattern that allows you to extend or modify the behavior of functions or methods without modifying their actual code. Decorators are applied using the @decorator syntax and are a concise way to wrap a function or method with additional functionality.

It helps you to off/on some functionality.

def log_function_call(func):
    def wrapper(*args):
        print(f"Calling {func.__name__} with arguments {args}")
        result = func(*args)
        print(f"{func.__name__} execution completed.")
        return result
    return wrapper

@log_function_call
def add_numbers(a, b):
    return a + b

@log_function_call
def multiply_numbers(x, y):
    return x * y

# Calling decorated functions
result_add = add_numbers(3, 5)
print(result_add)
result_multiply = multiply_numbers(4, 6)
print(result_multiply)

Output:

Calling add_numbers with arguments (3, 5)
add_numbers execution completed.
8
Calling multiply_numbers with arguments (4, 6)
multiply_numbers execution completed.
24

Now if we comment out the decorator,

def log_function_call(func):
    def wrapper(*args):
        print(f"Calling {func.__name__} with arguments {args}")
        result = func(*args)
        print(f"{func.__name__} execution completed.")
        return result
    return wrapper

# @log_function_call
def add_numbers(a, b):
    return a + b

# @log_function_call
def multiply_numbers(x, y):
    return x * y

# Calling decorated functions
result_add = add_numbers(3, 5)
print(result_add)
result_multiply = multiply_numbers(4, 6)
print(result_multiply)

Output:
8
24