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Python — Simplifying Decorators

🐍 Decorators can be complex. But if you study the following, you will understand it in the best form.

Step 1: Create Function

Input
def my_function():
    print('Step 1: Create first function') 

my_function()

Output
Step 1: Create first function

Step 2: Create Decorator

Input
def my_decorator(func):
    print('Step 2: Create a decorator. A decorator is a function')
    func()
    print('Step 3: Call first function') 

@my_decorator
def my_function():
    print('Step 1: Create first function') 

my_function()

Output
Step 2: Create a decorator. A decorator is a function
Step 1: Create first function
Step 3: Call first function

Step 3: Add a function and  decorator within the decorator

Input
import functools

def my_decorator(func):
    @functools.wraps(func)
    def func_that_runs_func():
        print('Step 2: Create a decorator. A decorator is a function')
        func()
        print('Step 3: Call first function')
    return func_that_runs_func()

@my_decorator
def my_function():
    print('Step 1: Create first function')

my_function()
Output
Step 2: Create a decorator. A decorator is a function
Step 1: Create first function
Step 3: Call first function

Step 3: Passing an argument to a decorator

Input
import functools

def my_decorator_with_argument(num):
    def my_decorator(func):
        @functools.wraps(func)
        def func_that_runs_func(*args, **kwargs):
            if num==56:
                func()
            else:
                print(num)
            print('Step 3: Call first function')
        return func_that_runs_func()
    return my_decorator

@my_decorator_with_argument(56)
def my_function():
    print('Step 1: Create first function')

my_function()
Output
Step 1: Create first function
Step 3: Call first function
Use tutorialspoint to run code online
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