[Python-Dev] Re: __metaclass__ and __author__ are already decorators

[Phillip J. Eby]

At 06:54 PM 8/21/04 -0400, Paul Morrow wrote:
>Thanks.  Of the 5 examples there, the first two are apparently not 
>implemented correctly, as they expect that the function/class to be 
>decorated is passed directly to them, rather than to the function they 
>return.  Would you agree?  I pasted them here for your consideration...

They're correct.  You're missing the fact that '@x' and '@x()' are not the 
same thing.  '@x' means 'func=x(func)', while '@x()' means 'func = 
x()(func)'.  There's no inconsistency here at all, it's just ordinary 
Python semantics.

The only time a decorator needs to return a function is if it needs 
arguments other than the function being decorated.  In which case, it might 
properly be termed a decorator factory, i.e. a function returning a 
decorator.  Thus, in the '@' syntax, a decorator expression is always 
either '@decorator' or '@decorator_factory(arguments)'.