On 07 May 2011 02:49:53 GMT, Steven D'Aprano <steve+comp.lang.pyt...@pearwood.info> wrote: : On Fri, 06 May 2011 16:05:09 -0400, Adam Tauno Williams wrote: : : > I'd never accept code like "if not x" as an empty test. : : So much the worse for you then. : : The point of the "if x" idiom is that it is a polymorphic test which is : independent of the type.
Normally, polymorphisms implies multiple forms only, where the different forms has some form of common interpretation. That's what makes polymorphism useful and helpful, increasing legibility. In this case, the interpretation of an arbitrary object as a boolean is peculiar for python. An empty list is a real, existing object, and the supposition that [] be false is counter-intuitive. It can be learnt, and the shorthand may be powerful when it is, but it will confuse many readers. -- :-- Hans Georg -- http://mail.python.org/mailman/listinfo/python-list
