Decorators in python.

Question

I made the decorators course in solo learn but I don't have pro, so I couldn't try it. I understand nothing! Can someone explain me decorators, higher order functions and this functions in functions AND give me examples why and how to use? This course I so short and badly to understand!!!

Answer 1

you don't need a pro account to write decorator functions.
there are external sources that can help you learn about decorators.

https://realpython.com/primer-on-JUMP_LINK__&&__python__&&__JUMP_LINK-decorators/

yes, i agree, the courses have become less and less educational with each revision.

not enough explanation and examples, all for the sake of keeping the lesson format consistent and 'cute'. a case of form over function.

anyway, decorators are higher-order functions.

they accept functions as arguments. they call the function internally and perform additional operations on the result.

the @decorator is just a convenient syntax sugar.

the lesson have this example:

def uppercase(func):
def wrapper():
orig_message = func()
modified_message = orig_message.upper()
return modified_message
return wrapper

@uppercase
def greet():
return "Welcome!"

# Using the decorated function
print(greet())

if you comment out @uppercase, you could use uppercase like:

print(uppercase(greet)())

Answer 2

Thank you! This article is so much better than the sololearn course!

Answer 3

why this ⬇️?
uppercase(greet)()

because uppercase returns another function -> wrapper. you have to call that to get the final result. uppercase(greet)() is the same as wrapper().

it's awkward, thus the @uppercase decorator syntax. then you just have to use greet().

Answer 4

Can you give an example for what it is really useful?

Answer 5

the RealPython link have a few examples at the end. i think it's commonly used in Flask, class decorators, lru cache, etc...

Answer 6

But RealPython isn't free

Answer 7

some articles are free.

Answer 8

Ok