Question concerning Python decorators

Question

In the SL-Python-course there is the example:

# begin of code
def decor(func):
def wrap():
print("============")
func()
print("============")
return wrap

@decor
def print_text():
print("Hello world!")

print_text()
# end of code

I do not understand, how I would have to change the code to print common strings in the function print_text().

I changed the code into:

# begin of code
def decor(func,x):
def wrap(x):
print("============")
func(x)
print("============")
return wrap(x)

@decor
def print_text(x):
print(x)

print_text("Hello world!")
# end of code

This produces errors. Could somebody please correct the second code that I can see how to enter variables in decorators.

Answer 1

I am not familiar with decorators, but this code runs fine.

https://code.sololearn.com/cHaWQtg4SE5m/?ref=app

Answer 2

It's really not that hard, Jan. Just think of this:

@dec
def func():
pass

As this:

def func():
pass
func = dec(func)

-------------------------

All that our decorator function (dec) is doing here is that:
1. It takes in a function
2. It then defines a new function, that calls the first function along with doing other
things that add functionality to the first function (in most cases)
3. Finally, it returns the new function.

So after applying the decorator, when we call the original function with some arguments, we are really just calling the new (wrap) function with the same arguments.

李立威's answer demonstrates the same.

-------------------------

If you're still confused, try this video. It helped me get the concept
https://www.youtube.com/watch?v=MYAEv3JoenI

Let me know if I can clear anything else up :)

Answer 3

Look at my answer in github https://github.com/chinua-luo/learning_python_record/blob/master/decor.py

Answer 4

I accidentally make this code, and I think that it may help in understanding decorators better.

https://code.sololearn.com/c7w0aAy4P6sf/?ref=app
https://code.sololearn.com/cabFO2TqM1an/?ref=app

Answer 5

Here's an example:
https://code.sololearn.com/cD09ijlIS6Ev/?ref=app

Answer 6

I think this could help to understand decoration
https://code.sololearn.com/cXiJWAB6AhS9/?ref=app