Ben Finney writes: > How can I ensure incidental names don't end up in the class > definition, with code that works on both Python 2 and Python 3? > > With the following class definition, the incidental names `foo` and > `bar`, only needed for the list comprehension, remain in the `Parrot` > namespace:: > > __metaclass__ = object > > class Parrot: > """ A parrot with beautiful plumage. """ > > plumage = [ > (foo, bar) for (foo, bar) in feathers.items() > if bar == "beautiful"] > > assert hasattr(Parrot, 'plumage') # ← okay, has the wanted name > assert not hasattr(Parrot, 'foo') # ← FAILS, has an unwanted name > assert not hasattr(Parrot, 'bar') # ← FAILS, has an unwanted name [- -] > How can I write the class definition with the list comprehension and > *not* keep the incidental names — in code that will run correctly on > both Python 2 and Python 3?
Make them an implementation detail: plumage = [ (__foo__, __bar__) for (__foo__, __bar__) in feathers.items() if __bar__ == "beautiful" ] -- https://mail.python.org/mailman/listinfo/python-list