>
>
> Do you propose to
> 1. Only use StringKeyDicts when non-string keys are not possible?  (Where
> would this be?)
> 2. Switch to a normal dict when a non-string key is added?  (But likely
> not switch back when the last non-string key is removed.)
> 3. Deprecate and remove the option to add non-string keys to namespace
> dicts?  (Proposed and rejected at least once as not gaining much.)
>
>
>

2. We already do such hack for key sharing dict.
And yes, deleting non string key doesn't switch back. d[0]=0; del d[0];
loop must be amortized O(1).
Only dict.clear() switches back.