Steve Holden wrote: > Fuzzyman wrote: > > Steven D'Aprano wrote: > > > >>On Wed, 08 Feb 2006 13:58:13 +1100, Delaney, Timothy (Tim) wrote: > >> > >> > >>>adam johnson wrote: > >>> > >>> > >>>>Hi All. > >>>>I was wondering why defining a __call__ attribute for a module > >>>>doesn't make it actually callable. > >>> > >>>For the same reason that the following doesn't work > >> > >>[snip example] > >> > >>>The __call__ attribute must be defined on the class (or type) - not on > >>>the instance. A module is an instance of <type 'module'>. > >> > >>That's not a _reason_, it is just a (re-)statement of fact. We know that > >>defining a __call__ method on a module doesn't make it callable. Why not? > >>The answer isn't "because defining a __call__ method on a module or an > >>instance doesn't make it callable", that's just avoiding the question. > >> > >>Someone had to code Python so that it raised an error when you try to call > >>a module object. Is there a reason why module() should not execute > >>module.__call__()? I would have thought that by the duck typing principle, > >>it shouldn't matter whether the object was a class, a module or an int, if > >>it has a __call__ method it should be callable. > >> > > > > > > It would nice if you could make modules callable. > > > Right. While we're at it, why don't we make strings callable. Calling a > string could call the function whose name (in some namespace or other) > was in the string. And we can make integers callable too - that could > just assume that the integer was the address of a function to be called. > > In case you think I'm joking, I am. > > Why should a module be callable? What's the advantage? Should we be able > to add two modules together, yielding a module that contains all the > code of both modules? What happens if I multiply a module by two - > presumably the result should be the same as adding a module to itself? > Perhaps we should be able to divide a module by a function? > > The pursuit of orthogonality, while admirable, can lead to insanity if > pushed too far. >
Sure - feel free to venture as far down the road of insanity as you like :-) To pursue your analogy, why don't we answer all usenet posts by pushing suggestions to ridiculous levels ? ;-) What would actually be the problem with allowing modules to define a __call__ though ? This would allow for nice clean namespaces at the module level. Ok, so there are other ways of doing it - but it's not at all illogical. Fuzzyman http://www.voidspace.org.uk/python/index.shtml > regards > Steve > -- > Steve Holden +44 150 684 7255 +1 800 494 3119 > Holden Web LLC www.holdenweb.com > PyCon TX 2006 www.python.org/pycon/ -- http://mail.python.org/mailman/listinfo/python-list
