Returns True iff o1 and o2 are of the same class lineage (that is, a direct line of descent, without branches).

def same_lineage(o1, o2):
    '''Returns True iff o1 and o2 are of the same class lineage (that is, a direct line of descent, without branches).'''
    def comp(x, y):
        return issubclass(x, y) or issubclass(y, x)

    if isinstance(o1, type) and isinstance(o2, type):
        return comp(o1, o2)
    elif not (isinstance(o1, type) or isinstance(o2, type)):
        return comp(type(o1), type(o2))
    raise TypeError("Cannot compare type and object")