> ===== Original Message From tripie@[...].org (Tomas Styblo) =====
> """
> Static class members ?
> 
> Hello. I've found no way to properly create static data members in
> Python classes.
> By static members I mean data that are shared by all instances of a
> class.
> A textbook example of usage of static data is a counter of all
> instances of said class.
> I tried the following:
> """
> 
> # Beginning of a module.
> 
> class Parent:
> 
>     INSTANCES = 0
> 
>     def __init__():
>         Parent.INSTANCES = Parent.INSTANCES + 1
> 
>     def get_INSTANCES():
>         return Parent.INSTANCES
> 
> 
> """ That works OK. Problems come when I derive a new class from this
> Parent.
>     Inherited methods in the derived class then reference the static
> data in
>     Parent. This is not what I expect and need.

Maybe you want something like this?

#---begin code

class Parent:
    counter = 0
    def __init__(self):
        self.__class__.counter += 1
    def getcounter(self):
        return self.__class__.counter

class Child(Parent):
    counter = 0 # set a new counter for this class, so it won't
                # use Parent's counter

# test it...
p1 = Parent()
p2 = Parent()
print p2.getcounter()

c1 = Child()
print c1.getcounter()   # 1, not 3

#---end code

HTH,

--Hans Nowak


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