Lorenzo Di Gregorio <[EMAIL PROTECTED]> wrote: > When employing Python it's pretty straightforward to translate the > instance to an object. > > instance = Component(input=wire1,output=wire2) > > Then you don't use "instance" *almost* anymore: it's an object which > gets registered with the simulator kernel and gets called by reference > and event-driven only by the simulator kernel. We might reuse the > name for calling some administrative methods related to the instance > (e.g. for reporting) but that's a pretty safe thing to do. Of course > all this can be done during initialization, but there are some good > reasons (see Verilog vs VHDL) why it's handy do be able to do it > *anywhere*. The annoying problem was that every time the program flow > goes over the assignment, the object gets recreated.
If you originally set, e.g., instance = None then using in your later code: instance = instance or Component(...) will stop the multiple creations. Other possibilities include using a compound name (say an.instance where 'an' is an instance of a suitable container class) and overriding the __new__ method of class Component so that it will not return multiple distinct objects with identical attributes. "Has this *plain* name ever been previously assigned to anything at all" is simply not a particularly good condition to test for (you COULD probably write a decorator that ensures that all uninitialized local variables of a function are instead initialized to None, but I'd DEFINITELY advise against such "black magic"). Alex -- http://mail.python.org/mailman/listinfo/python-list
