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. 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
