Install an handler for unhandled exceptions is not something new: there is already sys.displayhook and sys.excepthook.
I'm not sure that it's useful to get the "default" handler. Just give access to the current handler. So when you setup a new handler, just call the previous if you don't know what to do with it. It is the design chosen for the new malloc API, PEP 445. So you just need two function: get and set. For sys.displayhook/excepthook, the default is stored in sys.__displayhook/excepthook__. Victor
