It would be extremely unlikely that you would replicate the name as a local variable if it was in a dict, but regardless a dict doesn't have that limitation. The namespace thing is atrocious and bad design -- no straightforward way to iterate over them, merging/updating them is awful, collides with keyword methods (keys, items, etc.), and so on; thankfully more modern argument parsing libraries didn't repeat this mistake. It's just a shame this ended up in the standard library, but then Python standard library has never really been any good, e.g. logging and urllib1234567.