newbe question

[John Thingstad]

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 ?