newbe question

[Don O'Donnell]

John Thingstad wrote:
> 
> I wrote the following function to use polymorphism.
> 
> def rootClassName(var):
>     """Return the name of the root of a sigle inheretance class tree.
>     If multiple inheritance is used the leftmost class is traversed."""
>     if type(var) is ClassType:
>         cls = var
>         while len(cls.__bases__) != 0:
>             cls = cls.__bases__[0]
>         return cls.__name__
>     else:
>         return ""
> 
> Is there a built in function to do this ?
> 

Not that I know of. 

But just a note on Pythonic style --

Okay (but a lot of unnecessary processing cycles going on here):
        while len(cls.__bases__) != 0:

Better (!=0 is redundant at the end of a logical expression):
        while len(cls.__bases__):

Best (an empty sequence evaluates as false in a boolean context):
        while cls.__bases__:

Cheers,
Don