You can use Bar = superClassCreator() in foo (at the module level).
Alternatively, from another module, you can add Bar as an attribute on foo:
import foo
foo.Bar = superClassCreator()
or, if the name must be taken from the generated class:
import foo
generatedClass = superClassCreator()
setattr(foo, generatedClass.__name__, generatedClass)
From within the foo module, you can set it directly on globals():
generatedClass = superClassCreator()
globals()[generatedClass.__name__] = generatedClass
del generatedClass
with an optional del statement to remove the generatedClass name from the namespace again.