Message 63783 - Python tracker

I am commenting on issue2371 patch here, so that I does not get lost in
a non-showstopper issue.  Taek, please reattach your patch here when you
get a chance.

With the additional -3 logic, code duplication between tuple and
non-tuple case becomes unbearable.  I suggest separating both string and
subclass checks in a separate function.