On Nov 21, 5:11 pm, Joe Strout <[EMAIL PROTECTED]> wrote:
> I have a function that takes a reference to a class, and then
> instantiates that class (and then does several other things with the
> new instance). This is easy enough:
>
> item = cls(self, **itemArgs)
>
> where "cls" is the class reference, and itemArgs is obviously a set of
> keyword arguments for its __init__ method.
>
> But now I want to generalize this to handle a set of mix-in classes.
> Normally you use mixins by creating a class that derives from two or
> more other classes, and then instantiate that custom class. But in my
> situation, I don't know ahead of time which mixins might be used and
> in what combination. So I'd like to take a list of class references,
> and instantiate an object that derives from all of them, dynamically.
>
> Is this possible? If so, how?
Easily:
derived_cls = type('Derived', (cls1, cls2, *rest_classes), {})
item = derived_cls(**itemArgs)
You will probably want to cache the generated classes so that at most
one class is created for each combination of mixins.
HTH,
George
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