Decorator

[Martin Blume]

"bruno at modulix" schrieb 
> 
> What Python 2.4 adds is only syntactic sugar for decorators. 
> You can do the same - somewhat more explicitely - in 2.3.
> 
> > What is the decorator useful for?
> 
> 
> The whole things looks like this:
> 
> def deco(func):
>   print "decorating %s" % func.__name__
>   def _wrapper(*args, **kw):
>     print "%s called " % func.__name__
>     res = func(*args, **kw)
>     print "%s returned %s" % (func.__name__, str(res))
      return res
      ^^^^^^^^^^
Shouldn't here be a return res, so that wrapper
behaves like the original function?

>   return _wrapper
> 
> # python < 2.4
> def somefunc():
>   print "in somefunc"
>   return 42
> 
> somefunc = deco(somefunc)
> 

Thanks for the explanation.


Another question: Isn't decorating / wrapping usually
done at runtime, so that the @deco notation is pretty
useless (because you'd have to change the original 
code)?
What do I miss here?

Martin