how do I make a class global?

[harold]

basically, you can create new types on the fly using type() with three
arguments:

my_class = type("className",(BaseClass,),class_dict)

then, you can assign this vlass to the golbal namespace using
globals():

globals()["className"] = my_class

In your case, you would need to populate the class_dict by a function
object
that you parameterize to your needs, e.g.

def create_class(name,params) :
    def cls_init(self) :
        BaseClass.__init__(self)
        self.params = params

    cls_dict = {
        "__init__" : cls_init
    }

    new_cls = type(name,(BaseClass,),cls_dict)
    globals()[name] = new_cls

the result would be like this:

>>> create_class("test_class",42)
>>> instance = test_class()
>>> print instance.params
42