Another amazingly simple, yet clear, and most impressively - concise explanation of a technical topic from this channel. Thank you and please keep making more!
I saw your response of someone asking why do you need the wrapper function. I still don’t understand why you couldn’t just place everything in the wrapper function just inside the scope of log_function(func) and return func()
What you're tryin to say is why can't we place the code directly within the log_function. Okay let me explain According to you: def log_function(func): print(f"Calling function {func.__name__}") return func() @log_function def say_hello(): return "Hello, world!" This approach is okay but in limited cases, here log_function immediately calls the func() after printing the logging message. Now in this approach, you can't call the say_hello function as this will result in an error. print(say_hello()) # error print(say_hello) # code will execute There's no flexibility in this code, you can't do much. But but but... What if your function accepts some argument, how will you pass that argument? You can't pass it in the log_function, you need a nested function to handle all this. That's where a funtion like wrapper needed to preserve the signature of the original function and simultanoeusly modifying the behaviour. For instance, take a look at the following example: def log_function(func): def wrapper(*args): print(f"Calling function {func.__name__}") return func(*args) return wrapper @log_function def say_hello(text): return text print(say_hello("Hello")) Here, wrapper function handles all the stuff printing logging msg and returning the func with argument. Now when you called the say_hello function with an argument, it is passed to the log_function and log_function hand over to wrapper function to do the stuff. After all the the modification, the log_function returns the modified function.
The wrapper calls the original function and can modify the behaviour in some way which allows the decorator to extend the functionality of the original function without changing it's code directly. When you apply decorate a function, for instance, @log_function def say_hello(): The above code is equivalent to say_hello = log_function(say_hello) Now this say_hello name points to the wrapper function within log_function and if you print (print(say_hello), you'll get the wrapper function reference, which means the wrapper function is needed to preserve the original function's signature while adding the extra behaviour or functionality.
@@emasa97 for the first case, 2 will be squared first, we get 4 and the it will get summed 4+4=8 for the second case, 5 will get summed, we get 10 and then it will be squared 10**2=100 Hence, we got 8 and 100 in the video.
This is better than gold! Clearly explained. No BS.
Thanks!
Beautiful and elegant
Thank you! Cheers!
I've worked with decorators and used them in my Python programs, there are several built-in decorators also that can ease your work. Great one...
Good to know!
This channel is just great! No talking around, just clear and understandable knowledge in just 2 minutes. Thank you!
Wow, thanks!
Another amazingly simple, yet clear, and most impressively - concise explanation of a technical topic from this channel. Thank you and please keep making more!
Glad you liked it!
Pure gold
Thanks for appreciation.
Wonderfully explained, well done my friend!
Thank you kindly!
So much easier than the docs for beginners!!
Great
I remember asking for this topic. Just wanted to thank you, got it perfectly!
got u bruh
Great job. Keep producing the great stuff.
Thanks, will do!
Please make a video on Concurrency:
How do you achieve concurrency in Python? Please your explanation is so good !
definitely
really a good explanation every second worth
Glad you liked it
cool Thanks! beautifully explained
You're welcome!
Well explained... Keep it up
Thanks a lot
I have no word to thank keep it up
Yeah, thanks for the support
Very clean, thanks!
Glad you like it!
Great explanation. Worth it more views
Glad you think so!
Well explained.
Thanks
I saw your response of someone asking why do you need the wrapper function. I still don’t understand why you couldn’t just place everything in the wrapper function just inside the scope of log_function(func) and return func()
What you're tryin to say is why can't we place the code directly within the log_function. Okay let me explain
According to you:
def log_function(func):
print(f"Calling function {func.__name__}")
return func()
@log_function
def say_hello():
return "Hello, world!"
This approach is okay but in limited cases, here log_function immediately calls the func() after printing the logging message. Now in this approach, you can't call the say_hello function as this will result in an error.
print(say_hello()) # error
print(say_hello) # code will execute
There's no flexibility in this code, you can't do much.
But but but... What if your function accepts some argument, how will you pass that argument?
You can't pass it in the log_function, you need a nested function to handle all this. That's where a funtion like wrapper needed to preserve the signature of the original function and simultanoeusly modifying the behaviour. For instance, take a look at the following example:
def log_function(func):
def wrapper(*args):
print(f"Calling function {func.__name__}")
return func(*args)
return wrapper
@log_function
def say_hello(text):
return text
print(say_hello("Hello"))
Here, wrapper function handles all the stuff printing logging msg and returning the func with argument.
Now when you called the say_hello function with an argument, it is passed to the log_function and log_function hand over to wrapper function to do the stuff. After all the the modification, the log_function returns the modified function.
I must say, that is a great question. Appreciate it.
The same question I thought in my mind, but got the answer here.
@@2MinutesPythanks for explaining this
I needed that one❤
Why do I need a wrapper in my decorater function? What is the principle behind the wrapper?
The wrapper calls the original function and can modify the behaviour in some way which allows the decorator to extend the functionality of the original function without changing it's code directly.
When you apply decorate a function, for instance,
@log_function
def say_hello():
The above code is equivalent to say_hello = log_function(say_hello)
Now this say_hello name points to the wrapper function within log_function and if you print (print(say_hello), you'll get the wrapper function reference, which means the wrapper function is needed to preserve the original function's signature while adding the extra behaviour or functionality.
cool
👍
hey shouldn't the numbers be 16 and 50? it looks like the order of the decorators were the other way around :/
And could you explain how
@@2MinutesPy First sum 2+2=4, then square 4^2=16
Okay now I see the order is nested like 2:21. What you say at 2:08 was confusing for me
@@emasa97 for the first case, 2 will be squared first, we get 4 and the it will get summed 4+4=8
for the second case, 5 will get summed, we get 10 and then it will be squared 10**2=100
Hence, we got 8 and 100 in the video.
Let’s say a better way of writing helpers.
This all has been copy pasted from the chat gpt result
great