Decorators are flexible way to modify or extend behavior of functions or methods, without changing their actual code.
- A decorator is essentially a function that takes another function as an argument and returns a new function with enhanced functionality.
- Decorators are often used in scenarios such as logging, authentication and memorization, allowing us to add additional functionality to existing functions or methods in a clean, reusable way.
Now you can easily add on extra functionality with a decorator
@some_decorator
def simple_func():
# Do Simple stuff
return something
- We will go through the steps of manually building out a decorator ourselves, to show what @operator is doing behind the scenes
def func():
return 1
print(func())
print(func)
Output
1
def hello():
return "Hello!"
print(hello()) # Hello!
print(hello) #
#Copy one function to another
greet = hello
print(greet()) #'Hello!'
print(hello())
# o/p: 'Hello!'
# Deleting function
del hello
print(hello())
=> It will throw error as function hello deleted already
print(greet())
# o/p: 'Hello!'
Examples:1
def hello(name='Raju')
print('The hello() function has been executed!')
def greet():
return 't This is the greet() func inside hello!'
def welcome():
return 't This is welcome() inside hello'
print(greet())
print(welcome())
print('This is the end of the hello function!')
Examples:2
def hello(name='Raju')
print('The hello() function has been executed!')
def greet():
return 't This is the greet() func inside hello!'
def welcome():
return 't This is welcome() inside hello'
if name == 'Raju':
return greet
else :
return welcome
my_new_func = hello('Raju')
#o/P:
print(my_new_func())
Example:3
def cool():
def super_cool():
return 'I am very cool!'
return super_cool
some_func=cool()
some_func
some_func()
Passing function as a parameter to function
Example:1
def hello():
return 'Hi Jose!'
def other(some_def_func):
print('Other code runs here!')
print(some_def_func())
# passing raw function not executable function as parameter
other(Hello)
Output : It will throw error
Example:2
def new_decorator(orginal_func):
def wrap_func():
print('Some extra code, before the original function')
original_func()
print('Some extra code, after the original function!')
return wrap_func
def func_needs_decorator():
print("I want to be decorated!!")
func_needs_decorator()
o/p:
decorated_func = new_decorator(func_needs_decorator)
decorated_func()
# decorator
@new_decorator
def func_needs_decorator():
print("I want to be decorated!!")
# check the output
def func_needs_decorator():
print("I want to be decorated!!")
# check the output
References to extend your decorators concepts
1.Decorators are used for web frameworks
3.Creating web pages in python using Django
