using del() to 'unimport'

[Donnal Walter]

When the the following module is imported, I want only 'MyClass' (NOT
'Useful' and 'Mixin1') to be publicly accessible.

======= mymodule.py ==================
from utilities import Useful, Mixin1

class MyClass(Useful, Mixin1): pass
======================================


So my question is this: Is it an acceptable Python idiom to use del()
at the end of a module to remove previously imported names from the
global namespace as shown below? Is there a better alternative?

======= mymodule.py ==================
from utilities import Useful, Mixin1

class MyClass(Useful, Mixin1): pass

del(Useful)
del(Mixin1)
======================================