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

[Paul Morrow]

Phillip J. Eby wrote:

> 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)'.
> 

That's clear.  Thank you.