Rustom Mody <rustompm...@gmail.com>: > But for that Ive to use is > And as a teacher Ive to explain is > Might as well use C and get on with pointers > > To me 'is' is a can of worms
I'm not against "is," but it must be carefully defined and taught. As far as "x is None" is concerned, a key piece of information is presented on <URL: http://docs.python.org/3.2/library/constants.html>: None The sole value of the type NoneType. Unfortunately the page is a bit confusing. It says: A small number of constants live in the built-in namespace. So an essential characteristic of the None object (uniqueness) is mentioned in the middle of the discussion on the built-in namespace. The index doesn't contain an entry on NoneType. Thus, there might still be a nagging concern that a second NoneType object x such that x == None and x is not None could crop up (from native code, perhaps). Marko -- https://mail.python.org/mailman/listinfo/python-list
