Don Taylor <[EMAIL PROTECTED]> wrote: ... > Does Python have the notion of static class attributes?
No. > Just what was going on when I redefined my __slots__ attribute? Nothing. > It looks as if __slots__ is something really special, or I am managing Yep: it acts at *class-creation time*, only -- when the class statement executes (specifically: the class body executes, building a dict; that dict together with the classname and tuple of bases is passed to the metaclass, normally 'type' -- 'type' builds a slotted class iff it sees '__slots__' as a key in the dict, otherwise a normal class). Most other class attributes matter during the class's lifetime (e.g., __metaclass__ matters at class creation time, since it defines which metaclass is called to do the class creation, but it also matters later, since the current value of metaclass defines what specialmethods operate on the classobject), but __slots__ doesn't. A reasonable design choice: all existing instances couldn't be retroactively modified to change their slots, and having two instances of the "same class" that are incompatible with each other would be weird. Ideally, 'type' could transform a class's __slots__ into a readonly property (specifically a tuple of strings, to make it immutable), to catch any confusion about __slots__ ASAP. However, since __slots__ was meant for extremely RARE use, and only by very advanced programmers who fully know what they're doing, so nobody at the time took the trouble of building such strong fences around it (it wouldn't save us many of the huge stream of questions and misunderstandings we're getting all the time about it, anyway). Alex -- http://mail.python.org/mailman/listinfo/python-list
