You don't want to change what type
returns. You want to make your class a new-style one which (apart from many other advantages) means the string representation of this class object will mention its name, like all proper types (including but not limited to builtins). Change
class my_class:
...
to
class my_class(object):
...
If my_class
inherits from another class which is old-style itself, make that class new-stlye instead.