I love the decorator in Python!!!

[K.-Michael Aye]

On 2011-12-08 08:59:26 +0000, Thomas Rachel said:

> Am 08.12.2011 08:18 schrieb 88888 Dihedral:
>> I use the @ decorator to behave exactly like a c macro that
>> does have fewer side effects.
>> 
>> I am wondering is there other interesting methods to do the
>> jobs in Python?
> 
> In combination with a generator, you can do many funny things.
> 
> 
> For example, you can build up a string:
> 
> def mkstring(f):
>      """Turns a string generator into a string,
>      joining with ", ".
>      """
>      return ", ".join(f())
> 
> def create_answer():
>      @mkstring
>      def people():
>          yield "Anna"
>          yield "John"
>          yield "Theo"
> 
>      return "The following people were here: " + people
> 
> 
> Many other things are thinkable...
> 
> 
> Thomas

I am still perplexed about decorators though, am happily using Python 
for many years without them, but maybe i am missing something?
For example in the above case, if I want the names attached to each 
other with a comma, why wouldn't I just create a function doing exactly 
this? Why would I first write a single name generator and then decorate 
it so that I never can get single names anymore (this is the case, 
isn't it? Once decorated, I can not get the original behaviour of the 
function anymore.
So, above, why not
def mkstring(mylist):
with the same function declaration and then just call it with a list of 
names that I generate elsewhere in my program?
I just can't identify the use-case for decorators, but as I said, maybe 
I am missing something.

Michael